UMIACS - User contributions [en]

Printing

2011-02-10T20:42:02Z

Pjk:

==Printing==

* [[PrinterQueueNaming|Selecting A Print Queue (Color, Banners, etc)]]

* [[CUPS|Linux and UNIX Printing Guide (Linux and Solaris)]]

* [[WirelessPrinting|Printing from the wireless or Non-UMIACS Networks]]

* [[WindowsPrinting|Windows Printing Guide]]

* [[OSXPrinting|Mac OS X Printing Guide]]

* [[UNIXPrinting|Legacy UNIX Printing Guide (Linux and Solaris)]]

Main Page

2011-02-10T20:19:32Z

Pjk:

__NOTOC__
==Anouncements==

===New Torque/MAUI System on the [[OpenLAB]] Cluster===
When: Monday, February 14 at 8:30AM

This coming Monday, February 14 we will be installing a new version of the Torque/MAUI service on the [[OpenLAB]] cluster. The new version will provide improved stability, fix several bugs, and allow compatibility with future feature enhancements. Logins to openlab.umiacs.umd.edu, opensub00, and opensub01 will be unaffected. We expect to return the queue to full operation by 9:00 AM.

The upgrade process will stop any running jobs and will empty the queue. All running or queued jobs will need to be re-submitted. Please contact the UMIACS Help Desk at staff@umiacs.umd.edu or 301-405-1775 if you have any questions or concerns.

===New UNIX Print System===
We are pleased to announce the immediately available [[CUPS]] print system for our UNIX (rhel/ubuntu) users. Please contact staff@umiacs.umd.edu with any issues.

<startFeed />
==Technical Reference==

Welcome to UMIACS Wiki. This is the main place to find documentation and information about your account and the technical services that UMIACS offers. If this is your first time please start here [[GettingStarted| Getting Started]].

We provide many [[CoreServices|Core Services]] which include [[EMail]], [[Backups]] and [[VPN]].

We have lots of specific [[LabFacilities|Lab Facilities]] that you may be interested in.

Please check here if you are interested in [[OrderingEquipment|Ordering Equipment]].

Main Page

2010-10-13T13:35:37Z

Pjk:

__NOTOC__
==Anouncements==
<startFeed />
===Comcast DNS Issues===
We are currently experiencing issues with Comcast home internet in PG county not correctly handling DNS resolution for UMIACS hostnames, that can seem to be affecting connectivity to UMIACS.

If you are having problems getting to UMIACS hosts you can use our name servers to resolve those specific host names then connect using the IP addresses you lookup. Our name servers are 128.8.120.19, 128.8.120.50, and 128.8.132.75 to use this information to get the ip address of the host somehost.umiacs.umd.edu you would use the command "nslookup somehost.umiacs.umd.edu 128.8.120.19", from a linux, windows or mac command prompt.

Unfortunately the problem seems to lie in an interaction of Comcast's name servers with those run by OIT, but we are looking into ways we can interact with those parties to get this issue resolved.
<endFeed />

==Technical Reference==

Welcome to UMIACS Wiki. This is the main place to find documentation and information about your account and the technical services that UMIACS offers. If this is your first time please start here [[GettingStarted| Getting Started]].

We provide many [[CoreServices|Core Services]] which include [[EMail]], [[Backups]] and [[VPN]].

We have lots of specific [[LabFacilities|Lab Facilities]] that you may be interested in.

Please check here if you are interested in [[OrderingEquipment|Ordering Equipment]].

Main Page

2010-10-07T13:11:28Z

Pjk:

__NOTOC__
==Anouncements==
<startFeed />
===Off Campus Connectivity Problems 9:00AM, 10/7===
The University is currently experiencing issues with off campus internet connectivity. We are in contact with Campus OIT's Network Operations Center and will update this page as soon as we know more.
<endFeed />

<startFeed />
===Comcast DNS Issues===
We are currently experiencing issues with Comcast home internet in PG county not correctly handling DNS resolution for UMIACS hostnames, that can seem to be affecting connectivity to UMIACS.

If you are having problems getting to UMIACS hosts you can use our name servers to resolve those specific host names then connect using the IP addresses you lookup. Our name servers are 128.8.120.19, 128.8.120.50, and 128.8.132.75 to use this information to get the ip address of the host somehost.umiacs.umd.edu you would use the command "nslookup somehost.umiacs.umd.edu 128.8.120.19", from a linux, windows or mac command prompt.

Unfortunately the problem seems to lie in an interaction of Comcast's name servers with those run by OIT, but we are looking into ways we can interact with those parties to get this issue resolved.
<endFeed />

==Technical Reference==

Welcome to UMIACS Wiki. This is the main place to find documentation and information about your account and the technical services that UMIACS offers. If this is your first time please start here [[GettingStarted| Getting Started]].

We provide many [[CoreServices|Core Services]] which include [[EMail]], [[Backups]] and [[VPN]].

We have lots of specific [[LabFacilities|Lab Facilities]] that you may be interested in.

Please check here if you are interested in [[OrderingEquipment|Ordering Equipment]].

Main Page

2010-09-21T22:36:16Z

Pjk:

__NOTOC__
==Anouncements==
<startFeed />

===UMIACS Linux Systems Reboot===

'''When: Thursday 9/23 8pm - Friday 9/24 12am'''

This past weekend a critical security vulnerability was revealed for Linux systems. A patch is now available for this exploit, designated CVE-2010-3081. To implement this fix we will need to reboot all affected Linux systems which will install a new, secure kernel version. Due to the seriousness of this vulnerability, we need to apply this fix as soon as possible and have scheduled a restart of all affected systems this Thursday, 9/23/10 at 8:00PM. We apologize for the limited notice but quick action is needed to ensure the security of our systems, users, and data. UMIACS technical staff is able to identify any systems that may be compromised and we have been diligently monitoring all UMIACS systems since the original announcement.

The specific version of Linux affected is Red Hat Enterprise Linux, Version 5. Unfortunately, this list includes most of the Institute's clusters, web services, database services, computational nodes, and workstations. If you are unsure whether one of the systems you use is affected, please refer to the complete list on our wiki here: https://wiki.umiacs.umd.edu/umiacs/index.php/LinuxRebootList-2010_09_21 .

Please send any questions or comments to [mailto:staff@umiacs.umd.edu staff@umiacs.umd.edu].

===UMIACS Web/FTP Filesystem migration===

'''When: Tuesday 9/21 10pm - Wednesday 9/22 2am'''

We are going to be migrating the main UMIACS web and ftp file system to a new backend storage system which will require both the file systems to be read-only and then offline for a very short period. There will only be a 15 minute window at the tail end of the maintenance window where we will not be serving web and ftp content. No other services within UMIACS will be affected.

Please send any questions or comments to [mailto:staff@umiacs.umd.edu staff@umiacs.umd.edu].

===Comcast DNS Issues===
We are currently experiencing issues with Comcast home internet in PG county not correctly handling DNS resolution for UMIACS hostnames, that can seem to be affecting connectivity to UMIACS.

If you are having problems getting to UMIACS hosts you can use our name servers to resolve those specific host names then connect using the IP addresses you lookup. Our name servers are 128.8.120.19, 128.8.120.50, and 128.8.132.75 to use this information to get the ip address of the host somehost.umiacs.umd.edu you would use the command "nslookup somehost.umiacs.umd.edu 128.8.120.19", from a linux, windows or mac command prompt.

Unfortunately the problem seems to lie in an interaction of Comcast's name servers with those run by OIT, but we are looking into ways we can interact with those parties to get this issue resolved.

===UMIACS Staff Jira===
We have upgraded our request tracker to [[Jira]]. Please email [mailto:staff@umiacs.umd.edu staff@umiacs.umd.edu] if you have questions or comments.

<endFeed />

==Technical Reference==

Welcome to UMIACS Wiki. This is the main place to find documentation and information about your account and the technical services that UMIACS offers. If this is your first time please start here [[GettingStarted| Getting Started]].

We provide many [[CoreServices|Core Services]] which include [[EMail]], [[Backups]] and [[VPN]].

We have lots of specific [[LabFacilities|Lab Facilities]] that you may be interested in.

Please check here if you are interested in [[OrderingEquipment|Ordering Equipment]].

Main Page

2010-09-21T22:36:01Z

Pjk:

__NOTOC__
==Anouncements==
<startFeed />

===UMIACS Linux Systems Reboot===

'''When: Thursday 9/23 8pm - Friday 9/24 12am'''

Hi~

This past weekend a critical security vulnerability was revealed for Linux systems. A patch is now available for this exploit, designated CVE-2010-3081. To implement this fix we will need to reboot all affected Linux systems which will install a new, secure kernel version. Due to the seriousness of this vulnerability, we need to apply this fix as soon as possible and have scheduled a restart of all affected systems this Thursday, 9/23/10 at 8:00PM. We apologize for the limited notice but quick action is needed to ensure the security of our systems, users, and data. UMIACS technical staff is able to identify any systems that may be compromised and we have been diligently monitoring all UMIACS systems since the original announcement.

The specific version of Linux affected is Red Hat Enterprise Linux, Version 5. Unfortunately, this list includes most of the Institute's clusters, web services, database services, computational nodes, and workstations. If you are unsure whether one of the systems you use is affected, please refer to the complete list on our wiki here: https://wiki.umiacs.umd.edu/umiacs/index.php/LinuxRebootList-2010_09_21 .

Please send any questions or comments to [mailto:staff@umiacs.umd.edu staff@umiacs.umd.edu].

===UMIACS Web/FTP Filesystem migration===

'''When: Tuesday 9/21 10pm - Wednesday 9/22 2am'''

We are going to be migrating the main UMIACS web and ftp file system to a new backend storage system which will require both the file systems to be read-only and then offline for a very short period. There will only be a 15 minute window at the tail end of the maintenance window where we will not be serving web and ftp content. No other services within UMIACS will be affected.

Please send any questions or comments to [mailto:staff@umiacs.umd.edu staff@umiacs.umd.edu].

===Comcast DNS Issues===
We are currently experiencing issues with Comcast home internet in PG county not correctly handling DNS resolution for UMIACS hostnames, that can seem to be affecting connectivity to UMIACS.

If you are having problems getting to UMIACS hosts you can use our name servers to resolve those specific host names then connect using the IP addresses you lookup. Our name servers are 128.8.120.19, 128.8.120.50, and 128.8.132.75 to use this information to get the ip address of the host somehost.umiacs.umd.edu you would use the command "nslookup somehost.umiacs.umd.edu 128.8.120.19", from a linux, windows or mac command prompt.

Unfortunately the problem seems to lie in an interaction of Comcast's name servers with those run by OIT, but we are looking into ways we can interact with those parties to get this issue resolved.

===UMIACS Staff Jira===
We have upgraded our request tracker to [[Jira]]. Please email [mailto:staff@umiacs.umd.edu staff@umiacs.umd.edu] if you have questions or comments.

<endFeed />

==Technical Reference==

Welcome to UMIACS Wiki. This is the main place to find documentation and information about your account and the technical services that UMIACS offers. If this is your first time please start here [[GettingStarted| Getting Started]].

We provide many [[CoreServices|Core Services]] which include [[EMail]], [[Backups]] and [[VPN]].

We have lots of specific [[LabFacilities|Lab Facilities]] that you may be interested in.

Please check here if you are interested in [[OrderingEquipment|Ordering Equipment]].

LabFacilities

2010-08-30T19:41:59Z

Pjk:

* [[OpenLAB]]
* [[CBCB|Center for Bioinformatics and Computational Biology]] (CBCB) http://www.cbcb.umd.edu
* [[CDIG|Center for Digital International Government]] (CDIG) http://www.umiacs.umd.edu/research/CDIG
* [[CFAR|Center for Automation Research]] (CFAR) http://www.cfar.umd.edu
* [[CHESS|Center for Human Enhanced Secure Systems]] (CHESS) http://chess.umiacs.umd.edu/
* [[CLIP|Computational Linguistics and Information Processing]] (CLIP) http://www.umiacs.umd.edu/research/CLIP
* [[CVL|Computer Vision Laboratory]] (CVL) http://www.cfar.umd.edu/cvl/
* [[DSSL|Distributed Systems Software Laboratory]] (DSSL) http://www.cs.umd.edu/projects/dssl
* [[FCMD|Fraunhofer Center at Maryland]] (FCMD) http://fc-md.umd.edu/
* [[GLCF|Global Land Cover Facility]] (GLCF) http://www.glcf.umiacs.umd.edu
* [[GVIL|Graphics and Visual Informatics Laboratory]] (GVIL) http://www.cs.umd.edu/gvil/
* [[HCIL|Human Computer Interaction Laboratory]] (HCIL) http://www.cs.umd.edu/projects/hcil
* [[KECK|Keck Lab for the Comp. Modeling of Visual Movement]] (KECK) http://www.umiacs.umd.edu/%7Elsd/kecklab.html
* [[LAMP|Language and Media Processing Laboratory]] (LAMP) http://lamp.cfar.umd.edu
* [[LCCD|Laboratory for Computational Cultural Dynamics]] (LCCD) http://www.umiacs.umd.edu/research/LCCD/
* [[LPDC|Laboratory for Parallel and Distributed Computing]] (LPDC) http://www.umiacs.umd.edu/research/LPDC
* [[MIND|Maryland Information and Network Dynamics Lab]] (MIND) http://mindlab.umd.edu/
* [https://wiki.umiacs.umd.edu/maxwell/index.php/Main_Page MaxWell - WiMaX Forum Applications Laboratory] (MaxWell) http://www.umiacs.umd.edu/research/maxwell/
* [[PIRL|Perceptual Interfaces and Reality Laboratory]] (PIRL) http://pirl.umd.edu/
* [[OpenGPU]]

SecureShell

2010-05-05T14:56:00Z

Pjk: /* Passwordless SSH with SSH Keys */

Secure Shell (or [http://en.wikipedia.org/wiki/Secure_Shell SSH]) is a network protocol allowing two computers to exchange data securely over an insecure network. By default use of SSH brings the user to a terminal, but the protocol can be used for other types of data transfer such as [[SFTP]] and [[SCP]].

==Connecting to an SSH Server==
Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS [[OpenLAB]].
# ssh bkirz@openlab.umiacs.umd.edu
This will give you access to a terminal on any one of the [[OpenLAB]] servers. Note that by default you will not have access to applications that require X11 to run.

On Windows XP or Vista hosts there are no SFTP clients installed by default. Users can install either which will enable SSH and SFTP access.

* [http://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY]
* [http://ttssh2.sourceforge.jp/ ttssh2]

Alternatively, all users can use the UMIACS Intranet SFTP Web Applet located [https://intranet.umiacs.umd.edu/ssh/ here] without installing any additional software.

==X11 Forwarding==
By default, SSH only gives the user shell access to a host. Enabling X11 Forwarding allows users to run applications with Graphical User Interfaces.

Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS [[OpenLAB]] using X11 Forwarding.
# ssh '''-X''' bkirz@openlab.umiacs.umd.edu

'''Note:''' Mac users must have X11 installed in their systems for X11 forwarding to work. This can be checked by looking for X11.app in /Applications/Utilities. You can find the installer [http://www.apple.com/support/downloads/x11formacosx.html here].

Windows users can enable X11 forwarding on UMIACS desktops by using cygwin to ssh -X.
If you do not have Cygwin, you will need to forward X through Xming.
First, enable X forwarding on your secure ssh client. The option is under tunneling in the ssh client settings. This only has to be done once.

[[Image:sshXForward.jpg]]

Next, click save in the main ssh appication window to save this setting.

After this has been done, every time you want to use X forwarding, you need to make sure Xming has been started (it will appear in your task tray) through the start menu programs.
Now, you will be able to use Xwindow programs from your ssh client.

Note that the UMIACS Intranet SFTP Web Applet does ''not'' allow X11 Forwarding.

==SSH Tunneling==

You can tunnel one or more ports through an SSH connection such that your packets will look like they are coming from the host you are tunneling to. This is helpful for services that you would be normally blocked by a firewall.

Please see the [[SecureShellTunneling]] page for more information.

==Passwordless SSH with SSH Keys==

There are some situations where it is important to be able to ssh without entering a password. This is mostly required when working in clusters. This is done using ssh keys. Instead of authenticating with a password, ssh can use a pre-defined set of encryption keys to establish an authorized connection.
To setup passwordless ssh, do the following.

First, you will need to create a ssh key pair. It is possible to use a password that you will need to enter at the beginning of your work session. This is preferable as it is more secure but may cause problems for some clustered work, particularly our TORQUE/MAUI clusters. If you simply hit '''[enter]''', you will never be prompted for a password when ssh'ing which can lead to security problems.

To create a '''''passwordless''''' key, type the following. '''NOTE: This is ''REQUIRED'' for our [[ClusterGuide|TORQUE/MAUI]]-based clusters!'''

# ssh-keygen -N "" -t dsa

To create a '''''password-protected''''' (more-secure) key, type the following. Do not use this option if you plan to use our any of [[ClusterGuide|TORQUE/MAUI]]-based clusters.

# ssh-keygen -t dsa

This will produce two files, '''id_dsa''' and '''id_dsa.pub''', the private and public keys respectively. Once you've created the keys, you will need to put them into place as follows:

# mkdir ~/.ssh
# chmod 700 ~/.ssh
# mv id_dsa ~/.ssh
# chmod 600 ~/.ssh/id_dsa
# touch ~/.ssh/authorized_keys2
# chmod 600 ~/.ssh/authorized_keys2
# cat id_dsa.pub >> ~/.ssh/authorized_keys2
# rm id_dsa.pub

It is '''very''' important that you keep your private key secure! Ensure that it is chmod'd to 600 and that you do not put it anywhere visible to other users!

If you did not select a passphrase when you generated your keys, you can now ssh without a password. If you did select a passphrase, you will need to activate the keys as follows:

# ssh-agent [SHELL]
# ssh-add -t [TIME]

In this case, "[SHELL]" is your preferred shell and "[TIME]" is the amount of time you'd like the key to be active in seconds. So, the following would start a bash shell with passwordless ssh active for 30 minutes:

# ssh-agent bash
# ssh-add -t 1800

You will be prompted for your passphrase and, when entered correctly, you will be able to ssh without entering a password.

To disable this functionality, simply delete your private key file ('''~/.ssh/id_dsa''') and remove the public key from your '''~/.ssh/authorized_keys2''' file.

==Further Information==
[http://www.openssh.org/ OpenSSH]

[http://www.openssh.com/windows.html Windows Clients]

SecureShell

2010-05-05T14:53:59Z

Pjk: Merged SSH Key stuff

Secure Shell (or [http://en.wikipedia.org/wiki/Secure_Shell SSH]) is a network protocol allowing two computers to exchange data securely over an insecure network. By default use of SSH brings the user to a terminal, but the protocol can be used for other types of data transfer such as [[SFTP]] and [[SCP]].

==Connecting to an SSH Server==
Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS [[OpenLAB]].
# ssh bkirz@openlab.umiacs.umd.edu
This will give you access to a terminal on any one of the [[OpenLAB]] servers. Note that by default you will not have access to applications that require X11 to run.

On Windows XP or Vista hosts there are no SFTP clients installed by default. Users can install either which will enable SSH and SFTP access.

* [http://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY]
* [http://ttssh2.sourceforge.jp/ ttssh2]

Alternatively, all users can use the UMIACS Intranet SFTP Web Applet located [https://intranet.umiacs.umd.edu/ssh/ here] without installing any additional software.

==X11 Forwarding==
By default, SSH only gives the user shell access to a host. Enabling X11 Forwarding allows users to run applications with Graphical User Interfaces.

Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS [[OpenLAB]] using X11 Forwarding.
# ssh '''-X''' bkirz@openlab.umiacs.umd.edu

'''Note:''' Mac users must have X11 installed in their systems for X11 forwarding to work. This can be checked by looking for X11.app in /Applications/Utilities. You can find the installer [http://www.apple.com/support/downloads/x11formacosx.html here].

Windows users can enable X11 forwarding on UMIACS desktops by using cygwin to ssh -X.
If you do not have Cygwin, you will need to forward X through Xming.
First, enable X forwarding on your secure ssh client. The option is under tunneling in the ssh client settings. This only has to be done once.

[[Image:sshXForward.jpg]]

Next, click save in the main ssh appication window to save this setting.

After this has been done, every time you want to use X forwarding, you need to make sure Xming has been started (it will appear in your task tray) through the start menu programs.
Now, you will be able to use Xwindow programs from your ssh client.

Note that the UMIACS Intranet SFTP Web Applet does ''not'' allow X11 Forwarding.

==SSH Tunneling==

You can tunnel one or more ports through an SSH connection such that your packets will look like they are coming from the host you are tunneling to. This is helpful for services that you would be normally blocked by a firewall.

Please see the [[SecureShellTunneling]] page for more information.

==Passwordless SSH with SSH Keys==

There are some situations where it is important to be able to ssh without entering a password. This is mostly required when working in clusters. This is done using ssh keys. Instead of authenticating with a password, ssh can use a pre-defined set of encryption keys to establish an authorized connection.
To setup passwordless ssh, do the following.

First, you will need to create a ssh key pair. It is possible to use a password that you will need to enter at the beginning of your work session. This is preferable as it is more secure but may cause problems for some clustered work, particularly our TORQUE/MAUI clusters. If you simply hit '''[enter]''', you will never be prompted for a password when ssh'ing which can lead to security problems.

To create a '''''passwordless''''' key, type the following. '''NOTE: This is ''REQUIRED'' for our [[ClusterGuide|TORQUE/MAUI]]-based clusters!'''

# ssh-keygen -N "" -t dsa

To create a '''''password-protected''''' (more-secure) key, type the following. Do not use this option if you plan to use our any of [[ClusterGuide|TORQUE/MAUI]]-based clusters.

# ssh-keygen -t dsa

The command will prompt you for a passphrase. If you use a password, you will need to enter it at the beginning of your work session. This is preferable as it is more secure but may cause problems for some clustered work, such as TORQUE/MAUI cluster. If you simply hit '''[enter]''', you will never be prompted for a password when ssh'ing which can lead to security problems.

This will produce two files, '''id_dsa''' and '''id_dsa.pub''', the private and public keys respectively. Once you've created the keys, you will need to put them into place as follows:

# mkdir ~/.ssh
# chmod 700 ~/.ssh
# mv id_dsa ~/.ssh
# chmod 600 ~/.ssh/id_dsa
# touch ~/.ssh/authorized_keys2
# chmod 600 ~/.ssh/authorized_keys2
# cat id_dsa.pub >> ~/.ssh/authorized_keys2
# rm id_dsa.pub

It is '''very''' important that you keep your private key secure! Ensure that it is chmod'd to 600 and that you do not put it anywhere visible to other users!

If you did not select a passphrase when you generated your keys, you can now ssh without a password. If you did select a passphrase, you will need to activate the keys as follows:

# ssh-agent [SHELL]
# ssh-add -t [TIME]

In this case, "[SHELL]" is your preferred shell and "[TIME]" is the amount of time you'd like the key to be active in seconds. So, the following would start a bash shell with passwordless ssh active for 30 minutes:

# ssh-agent bash
# ssh-add -t 1800

You will be prompted for your passphrase and, when entered correctly, you will be able to ssh without entering a password.

To disable this functionality, simply delete your private key file ('''~/.ssh/id_dsa''') and remove the public key from your '''~/.ssh/authorized_keys2''' file.

==Further Information==
[http://www.openssh.org/ OpenSSH]

[http://www.openssh.com/windows.html Windows Clients]

CUDA

2009-10-28T20:02:09Z

Pjk:

[[http://en.wikipedia.org/wiki/CUDA CUDA]] is a programming architecture developed by NVIDIA to allow General Purpose Computing on GPUs or '''"GPGPU"'''.

===CUDA Software on Linux===
The CUDA infrastructure comes in two parts.

First is the driver which installs libraries in /usr/lib.

Second is the CUDA toolkit. The currently supported CUDA toolkit is stored under /usr/local. Please change the "common.mk" settings in your CUDA SDK to set the CUDA root directory to "/usr/local"

You will also need to put the CUDA libraries in your LD_LIBRARY_PATH.
*If you are using a 64-bit machine this will be /usr/local/lib64.
*If you are using a 32-bit machine this will be /usr/local/lib.

Older versions of the CUDA toolkit are stored in /usr/local/stow/cudatoolkit_X.Y where X.Y is the version number. So, CUDA 2.2 is stored in /usr/local/stow/cudatoolkit2.2

SecureShell

2009-03-03T14:26:32Z

Pjk: added ssh key section

Secure Shell (or [http://en.wikipedia.org/wiki/Secure_Shell SSH]) is a network protocol allowing two computers to exchange data securely over an insecure network. By default use of SSH brings the user to a terminal, but the protocol can be used for other types of data transfer such as [[SFTP]] and [[SCP]].

==Connecting to an SSH Server==
Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS [[OpenLAB]].
# ssh bkirz@openlab.umiacs.umd.edu
This will give you access to a terminal on any one of the [[OpenLAB]] servers. Note that by default you will not have access to applications that require X11 to run.

On Windows XP or Vista hosts there are no SFTP clients installed by default. Users can install either which will enable SSH and SFTP access.

* [http://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY]
* [http://ttssh2.sourceforge.jp/ ttssh2]

Alternatively, all users can use the UMIACS Intranet SFTP Web Applet located [https://intranet.umiacs.umd.edu/ssh/ here] without installing any additional software.

==X11 Forwarding==
By default, SSH only gives the user shell access to a host. Enabling X11 Forwarding allows users to run applications with Graphical User Interfaces.

Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS [[OpenLAB]] using X11 Forwarding.
# ssh '''-X''' bkirz@openlab.umiacs.umd.edu

'''Note:''' Mac users must have X11 installed in their systems for X11 forwarding to work. This can be checked by looking for X11.app in /Applications/Utilities. You can find the installer [http://www.apple.com/support/downloads/x11formacosx.html here].

Windows users can enable X11 forwarding in PuTTY by opening the PuTTY Configuration Pane, and checking the box marked "Enable X11 Forwarding" under Categories->Connection->SSH->Tunnels.

Note that the UMIACS Intranet SFTP Web Applet does ''not'' allow X11 Forwarding.

==SSH Tunneling==

You can tunnel one or more ports through an SSH connection such that your packets will look like they are coming from the host you are tunneling to. This is helpful for services that you would be normally blocked by a firewall.

Please see the [[SecureShellTunneling]] page for more information.

==Passwordless SSH with SSH Keys==

There are some situations where it is important to be able to ssh without entering a password. This is mostly required when working in clusters. This is done using ssh keys. Instead of authenticating with a password, ssh can use a pre-defined set of encryption keys to establish an authorized connection. To setup passwordless ssh, do the following.

First, create an ssh key pair:

# ssh-keygen -t dsa

The command will prompt you for a passphrase. If you use a password, you will need to enter it at the beginning of your work session. This is preferable as it is more secure but may cause problems for some clustered work If you simply hit '''[enter]''', you will never be prompted for a password when ssh'ing which can lead to security problems.

This will produce two files, '''id_dsa''' and '''id_dsa.pub''', the private and public keys respectively. Once you've created the keys, you will need to put them into place as follows:

# mkdir ~/.ssh
# chmod 700 ~/.ssh
# mv id_dsa ~/.ssh
# chmod 600 ~/.ssh/id_dsa
# touch ~/.ssh/authorized_keys2
# chmod 600 ~/.ssh/authorized_keys2
# cat id_dsa.pub >> authorized_keys2
# rm id_dsa.pub

It is '''very''' important that you keep your private key secure! Ensure that it is chmod'd to 600 and that you do not put it anywhere visible to other users!

If you did not select a passphrase when you generated your keys, you can now ssh without a password. If you did select a passphrase, you will need to activate the keys as follows:

# ssh-agent [SHELL]
# ssh-add -t [TIME]

In this case, "[SHELL]" is your preferred shell and "[TIME]" is the amount of time you'd like the key to be active in seconds. So, the following would start a bash shell with passwordless ssh active for 30 minutes:

# ssh-agent bash
# ssh-add -t 1800

You will be prompted for your passphrase and, when entered correctly, you will be able to ssh without entering a password.

To disable this functionality, simply delete your private key file ('''~/.ssh/id_dsa''') and remove the public key from your '''~/.ssh/authorized_keys2''' file.

==Further Information==
[http://www.openssh.org/ OpenSSH]

[http://www.openssh.com/windows.html Windows Clients]

UNIXPrinting

2008-12-03T16:53:52Z

Pjk:

==Introduction==

UMIACS uses the LPRng spooling system to provide both a Berkeley UNIX interface to our network printing system.

The commands are located in /usr/local/bin. They include the programs 'lpr', 'lprm', 'lpq', and 'lpstat'.

All of the UNIX queues are configured to handle postscript. See the examples section for more information on how to print different file types.
Basic Commands

==lpr==

Use `lpr -Pprintername filename.ps` to submit the postscript file named filename.ps to the printer queue named printername. If no filename is specified, lpr reads from standard input. If no printer name is specified, then the job is discarded by the print server.

Additional options to specify media handling, page orientation, and double sided printing can be passed to the print spooler using one or more -Z options. Double sided printing is specified with -Zduplex. Page orientation is controlled with -Zportrait, -Zlandscape. Manual feed media (eg. transparencies) is specified with -Zmanual. Please note that not all printers support all -Z options.

==nscript==

Use `nscript -Pprintername filename.txt` to send the text file named filename.txt to the printer named printername. If no filename is specified, then nscript reads from standard input.

Nscript is a weak attempt to simulate Adobe Systems Incorporated nscript programs. It supports a handful of interesting arguments. With the '-G' argument, nscript generates gaudy output that includes header information on each page. The '-2' argument generates two column output and '-r' rotates the job's orientation to landscape mode.

==lprm==

Use 'lprm -Pprintername' to remove jobs from the queue named printername. With no further arguments, it removes the first removable job in the queue. Given a job's id as an argument, it will remove the specified job from the queue and you can remove all removable jobs from a queue with the argument "all".

You are able to remove items from the queue that you have submitted from anywhere, not just the computer from which the job was submitted.

==lpq==

Use 'lpq -Pprintername' to get the status of the queue named printername. With no further arguments, it will print the printer queue, the host queried, and the number of jobs in the queue. With the -l argument, it will specify the id, queue rank, the total size of the job in bytes, and any errors encountered in processing the job.

==Generate Postscript==

Postscript is a Page Description Language that is understood by high quality printers and typically generated by applications. There is a lot of documentation about using and programming in postscript, but for our purposes you'll just need to generate postscript from an existing text file.

You can generate postscript from an existing text file with textps. For example, to convert the Message of the Day file to a postscript file try `textps ... > file.ps`.

==Preview your job==

It's helpful to preview your postscript files before printing by calling Ghostview with `ghostview file.ps`.

Higher quality previewing is available using Ghostview's derivativegv. You can call it as `gv file.ps`.

Both commands should open a window that displays the contents of your postscript file.

==Choose a print queue==

All supported printers are listed at https://printers.umiacs.umd.edu/printers.

You can check list all the print queues with `lpq -a` and you can list just a single queue `lpq -Pprintername` -- eg. ps2109 with `lpq -Pps2109`.

==Send a print job==

After you choose a suitable printer (eg. ps2109), you can send your postscript file to the printer with `lpr -Pps2109 file.ps`.

==Monitor a print job==

You can monitor the job you sent to the printer (eg. ps2109) with `lpq -Pps2109`.

Lpq will return the following output:

[herzog 33] lpq -Pps2109
Printer: ps2109@lpr1 (dest raw@ps2109.umiacs.umd.edu) 'HP 8550 in AVW 2109'
Queue: 2 printable jobs
Server: pid 11833 active
Unspooler: pid 11837 active
Status: waiting for subserver to exit at 14:50:45.141
Rank Owner/ID Class Job Files Size Time
active fmccall@herzog+198 A 198 file.ps 4309 14:50:44
2 bargle@prime+199 A 199 hpss.ps 4309 14:50:45
Active connection from 128.8.120.247
Waiting connection from 128.8.120.247

==Remove a Print Job==

If you would like to remove your job from the queue, you should get the job's id from the output of `lpq`. You can remove it with `lprm -Pps2109 198`

From the output of lpq, I can see that the job id is 198 and I can remove it with lprm as follows:

[herzog 35] lprm -Pps2109 198
Printer ps2109@durer:
checking perms 'fmccall@herzog+198'
dequeued 'fmccall@herzog+198'

Often the last job listed in the printer queue has already spooled to the printer, and lprm will be unable to delete the job. In this case, the only way to cancel the job will be to press the 'cancel' button on the printer.

FilesystemDataStorage

2008-12-03T16:30:00Z

Pjk:

UMIACS recommends that any and all important data be stored on a redundant, backed-up file server. However, there are a number of cases where this is not feasible.

==Windows Local Storage==
Windows hosts at UMIACS store user directories on their local drives. Supported, UMIACS-managed hosts are automatically backed up using the Institute's backup system. Laptops and non-standard hosts are not automatically backed up and be manually backed up by their users.

==UNIX Local Storage==
UNIX machines use redundant, backed-up network file shares for user directories. Research data storage is also stored on redundant, backed-up network file shares and is generally available under /fs/

All UNIX machines also have local storage available for transitory use. These directories may be used to store temporary, local '''''COPIES''''' of data that is permanently stored elsewhere or as a staging point for output.

These directories may not, '''''under any circumstances''''', be used as permanent storage for unique, important data. UMIACS staff cannot recover damaged or deleted data from these directories and will not be responsible for data loss if they are misused.

Please note that '''/tmp''' in particular is at risk for data loss or corruption as that directory is regularly used by system processes and services for temporary storage.

These directories include:

- /tmp
- /scratch0, /scratch1, /scratch*
- any directory named in whole or in part "tmp", "temp", or "scratch".

==Locally Attached Storage==
Locally attached storage like USB flash drives and USB hard drives are very popular. However, these devices are significantly more vulnerable to data loss or theft than internal or networked data storage. In general, UMIACS discourages the use of locally attached network storage when any other option is available. Please note that these devices are prone to high rates of failure and additional steps should be taken to ensure that the data is backed up and that critical or confidential data is not lost or stolen.

CoreServices

2008-12-03T16:23:08Z

Pjk:

* [[Kerberos|Authenticaion (UMIACS KRB5/UNIX)]]

* [[PCDomain|Authentication (Windows/PC Domain)]]

* [[EMail]]

* [[Printing]]

* [[MailingLists|Mailing Lists]]

* [[OSSupport|Operating Systems Support]]

* [[NAS|Network Attached Storage]]

* [[Web|Web Services]]

* [[FileTransferProtocol |File Transfer Protocol]]

* [[Subversion|Revision Control (Subversion)]]

* [[Programming|Programming Languages]]

* [[Backups]]

* [[VPN|Virtual Private Networking]]

* [[WinXPRemoteAssist|Windows XP Remote Assistance]]

* [[LocalDataStorage|Local Data Storage]]

Main Page

2008-11-20T18:51:23Z

Pjk:

__NOTOC__
==Anouncements==
<startFeed />
*The Color printer in the helpdesk - cps3142 has been repaired and is once again available for use.
<endFeed />

==Technical Reference==

Welcome to UMIACS Wiki. This is main place to find documentation and information about your account and technical services that UMIACS offers. If this is your first time please start here [[GettingStarted| Getting Started]].

We provide many [[CoreServices|Core Services]] which include [[EMail]], [[Backups]] and [[VPN]].

We have lots of specific [[LabFacilities|Lab Facilities]] that you may be interested in.

Please check here if you are interested in [[OrderingEquipment|Ordering Equipment]].

==Additional Support==

If you need additional assistance, please contact the UMIACS Technical Staff.

The Technical Staff can be reached by sending email to [mailto:staff@umiacs.umd.edu staff@umiacs.umd.edu].

If you have a problem with your email or a problem that would be better addressed by speaking to directly to a staffer, you can call or visit our Help Desk,

Monday - Friday
9:00am - 12:30pm and 1:30pm - 5:00pm.

The Help Desk is located in Room [[AVW3142|3142]] of the A.V. Williams Building, and can be reached by phone at 301-405-1775.

PrinterQueueNaming

2008-11-19T16:53:19Z

Pjk:

==Printer Queues==

UMIACS uses a centralized print server to manage all of the printers in the Institute. See [Printing] for more details specific to your OS. We have developed a naming scheme for our printer queues based on the colors the printer can produce, the type of queue, the room number, and whether or not you wish to have a header page (called a "banner") printed at the beginning of your document.

The naming scheme is as follows:

* All color printers begin with a "c". Black & white is the default so nothing extra is needed.
* Then is either "ps" for a postscript queue or "pcl" for a PCL queue. Postscript and PCL are types of printer drivers. If you are unsure what this means, use "ps" for postscript.
* Then add the room number. All printers in the Bio Sciences Building also add the building number. E.g., room 3120H in BSB is "296-3120H" while room 3142 in AV Williams is "3142".
* Finally, if you do not want to print a banner page, add "nb".

[[Image:Printernaming.jpg]]

Some examples:

* cps3142nb is a color printer in AV Williams 3142 that will not print banners.
* ps3142 is a black & white printer in AV Williams 3142 that will print banners.
* pcl3142 is a black & white printer in AV Williams 3142 that will print banners but uses a PCL driver.
* cps296-3120Hb is a color printer in BSB that will print banners.

Printing

2008-11-19T16:26:41Z

Pjk: /* Printing */

==Printing==

* [[PrinterQueueNaming|Selecting A Print Queue (Color, Banners, etc)]]

* [[UNIXPrinting|UNIX Printing Guide (Linux and Solaris)]]

* [[WirelessPrinting|Printing from the wireless or Non-UMIACS Networks]]

* [[WindowsPrinting|Windows Printing Guide]]

* [[OSXPrinting|Mac OS X Printing Guide]]

MacOSPrinting

2008-11-19T16:25:32Z

Pjk:

OS X (versions 10.3 and 10.4)

If you are printing from OS X please follow these steps:

* Go to Applications->Utilities
* Click on:
[[Image:osxprinticon.jpg]]
* Press the Add icon
** Choose IP Printer
** Select 'Line Printer Daemon - LPD' for Protocol
** Address: lpr1.umiacs.umd.edu
** Queue: enter the printer name you wish to use (e.g. ps3142)
** Name: default is lpr1.umiacs.umd.edu, you WILL want to change this or if you add another printer they will both have the same name. Put in the name you want for the printer (e.g. ps3142).
** Print Using: the default will work most of the time. However, if you wish to use advanced features like duplexing, click the pull-down and choose "Select a driver to use..." This will bring up a list of printer models and a search field. You can then search for and select the appropriate driver for the printer you are adding.
** click add

[[Image:osxprint.jpg]]

UNIXPrinting

2008-11-19T16:20:27Z

Pjk: /* Choose a print queue */

==Introduction==

UMIACS uses the LPRng spooling system to provide both a Berkeley UNIX interface to our network printing system.

The commands are located in /usr/local/bin. They include the programs 'lpr', 'lprm', 'lpq', and 'lpstat'.

All of the UNIX queues are configured to handle postscript. See the examples section for more information on how to print different file types.
Basic Commands

==lpr==

Use `lpr -Pprintername filename.ps` to submit the postscript file named filename.ps to the printer queue named printername. If no filename is specified, lpr reads from standard input. If no printer name is specified, then the job is discarded by the print server.

Additional options to specify media handling, page orientation, and double sided printing can be passed to the print spooler using one or more -Z options. Double sided printing is specified with -Zduplex. Page orientation is controlled with -Zportrait, -Zlandscape. Manual feed media (eg. transparencies) is specified with -Zmanual. Please note that not all printers support all -Z options.

==lp==

==nscript==

Use `nscript -Pprintername filename.txt` to send the text file named filename.txt to the printer named printername. If no filename is specified, then nscript reads from standard input.

Nscript is a weak attempt to simulate Adobe Systems Incorporated nscript programs. It supports a handful of interesting arguments. With the '-G' argument, nscript generates gaudy output that includes header information on each page. The '-2' argument generates two column output and '-r' rotates the job's orientation to landscape mode.

==enscript==

GNU enscript is coming soon!

==lprm==

Use `lprm -Pprintername` to remove the first removable job from the print queue printername. You can remove a specific job from the queue by specifying its id as an argument and you can remove all removable jobs from a queue with the argument all.
lpq

Use 'lpq -Pprintername' to get the status of the queue named printername. With no further arguments, it will print the printer queue, the host queried, and the number of jobs in the queue. With the -l argument, it will specify the id, queue rank, the total size of the job in bytes, and any errors encountered in processing the job.

==lprm==

Use 'lprm -Pprintername' to remove jobs from the queue named printername. With no further arguments, it removes the first removable job in the queue. Given a job's id as an argument, it will remove the specified job from the queue.

You are able to remove items from the queue that you have submitted from anywhere, not just the computer from which the job was submitted.
Basic Tasks

==Generate Postscript==

Postscript is a Page Description Language that is understood by high quality printers and typically generated by applications. There is a lot of documentation about using and programming in postscript, but for our purposes you'll just need to generate postscript from an existing text file.

You can generate postscript from an existing text file with textps. For example, to convert the Message of the Day file to a postscript file try `textps ... > file.ps`.

==Preview your job==

It's helpful to preview your postscript files before printing by calling Ghostview with `ghostview file.ps`.

Higher quality previewing is available using Ghostview's derivativegv. You can call it as `gv file.ps`.

Both commands should open a window that displays the contents of your postscript file.

==Choose a print queue==

All supported printers are listed at https://printers.umiacs.umd.edu/printers.

You can check list all the print queues with `lpq -a` and you can list just a single queue `lpq -Pprintername` -- eg. ps2109 with `lpq -Pps2109`.

==Send a print job==

After you choose a suitable printer (eg. ps2109), you can send your postscript file to the printer with `lpr -Pps2109 file.ps`.

==Monitor a print job==

You can monitor the job you sent to the printer (eg. ps2109) with `lpq -Pps2109`.

Lpq will return the following output:

[herzog 33] lpq -Pps2109
Printer: ps2109@lpr1 (dest raw@ps2109.umiacs.umd.edu) 'HP 8550 in AVW 2109'
Queue: 2 printable jobs
Server: pid 11833 active
Unspooler: pid 11837 active
Status: waiting for subserver to exit at 14:50:45.141
Rank Owner/ID Class Job Files Size Time
active fmccall@herzog+198 A 198 file.ps 4309 14:50:44
2 bargle@prime+199 A 199 hpss.ps 4309 14:50:45
Active connection from 128.8.120.247
Waiting connection from 128.8.120.247

==Remove a Print Job==

If you would like to remove your job from the queue, you should get the job's id from the output of `lpq`. You can remove it with `lprm -Pps2109 198`

From the output of lpq, I can see that the job id is 198 and I can remove it with lprm as follows:

[herzog 35] lprm -Pps2109 198
Printer ps2109@durer:
checking perms 'fmccall@herzog+198'
dequeued 'fmccall@herzog+198'

Often the last job listed in the printer queue has already spooled to the printer, and lprm will be unable to delete the job. In this case, the only way to cancel the job will be to press the 'cancel' button on the printer.