Nexus/Vulcan

The Vulcan standalone cluster's compute nodes have folded into Nexus as of the scheduled maintenance window for August (Thursday 8/17, 5-8pm).

The Nexus cluster already has a large pool of compute resources made possible through leftover funding for the Brendan Iribe Center. Details on common nodes already in the cluster (Tron partition) can be found here.

The Vulcan cluster's standalone submission nodes vulcansub00.umiacs.umd.edu and vulcansub01.umiacs.umd.edu will be retired on Thursday, September 21st, 2023 during that month's maintenance window (5-8pm), as they are no longer be able to submit jobs to Vulcan compute nodes. Please use nexusvulcan00.umiacs.umd.edu and nexusvulcan01.umiacs.umd.edu for any general purpose Vulcan compute needs after this time.

Please see the Timeline section below for concrete dates in chronological order.

Please contact staff with any questions or concerns.

Usage

The Nexus cluster submission nodes that are allocated to Vulcan are nexusvulcan00.umiacs.umd.edu and nexusvulcan01.umiacs.umd.edu. You must use these nodes to submit jobs to Vulcan compute nodes. Submission from vulcansub00.umiacs.umd.edu or vulcansub01.umiacs.umd.edu is no longer available.

All partitions, QoSes, and account names from the standalone Vulcan cluster have been moved over to Nexus. However, please note that vulcan- is prepended to all of the values that were present in the standalone Vulcan cluster to distinguish them from existing values in Nexus. The lone exception is the base account that was named vulcan in the standalone cluster (it is also named just vulcan in Nexus).

Here are some before/after examples of job submission with various parameters:

Standalone Vulcan cluster submission command	Nexus cluster submission command
srun --partition=dpart --qos=medium --account=abhinav --gres=gpu:rtxa4000:2 --pty bash	srun --partition=vulcan-dpart --qos=vulcan-medium --account=vulcan-abhinav --gres=gpu:rtxa4000:2 --pty bash
srun --partition=cpu --qos=cpu --pty bash	srun --partition=vulcan-cpu --qos=vulcan-cpu --pty bash
srun --partition=scavenger --qos=scavenger --account=vulcan --gres=gpu:4 --pty bash	srun --partition=vulcan-scavenger --qos=vulcan-scavenger --account=vulcan --gres=gpu:4 --pty bash

Vulcan users (exclusively) can schedule non-interruptible jobs on Vulcan nodes with any non-scavenger job parameters. Please note that the vulcan-dpart partition has a GrpTRES limit of 100% of the available cores/RAM on vulcan## nodes plus 50% of the available cores/RAM on legacy## nodes, so your job may need to wait if all available cores/RAM (or GPUs) are in use. It also has a max submission limit of 500 jobs per user simultaneously so as to not overload the cluster. This is codified by the partition QoS named vulcan.

Please note that the Vulcan compute nodes are also in the institute-wide scavenger partition in Nexus. Vulcan users still have scavenging priority over these nodes via the vulcan-scavenger partition (i.e., all vulcan- partition jobs (other than vulcan-scavenger) can preempt both vulcan-scavenger and scavenger partition jobs, and vulcan-scavenger partition jobs can preempt scavenger partition jobs).

Nodes

There are currently 45 GPU nodes available running a mixture of NVIDIA RTX A6000, NVIDIA RTX A5000, NVIDIA RTX A4000, NVIDIA Quadro P6000, NVIDIA GeForce GTX 1080 Ti, NVIDIA GeForce RTX 2080 Ti, and NVIDIA Tesla P100 cards. There are also 2 CPU-only nodes available.

All nodes are scheduled with the SLURM resource manager.

Partitions

There are three partitions available to general Vulcan SLURM users. You must specify a partition when submitting your job.

• vulcan-dpart - This is the default partition. Job allocations are guaranteed.
• vulcan-scavenger - This is the alternate partition that allows jobs longer run times and more resources but is preemptable when jobs in other vulcan- partitions are ready to be scheduled.
• vulcan-cpu - This partition is for CPU focused jobs. Job allocations are guaranteed.

There are a few additional partitions available to subsets of Vulcan users based on specific requirements.

Accounts

Vulcan has a base SLURM account vulcan which has a modest number of guaranteed billing resources available to all cluster users at any given time. Other faculty that have invested in Vulcan compute infrastructure have an additional account provided to their sponsored accounts on the cluster, which provides a number of guaranteed billing resources corresponding to the amount that they invested.

If you do not specify an account when submitting your job, you will receive the vulcan account. If your faculty sponsor has their own account, it is recommended to use that account for job submission.

The current faculty accounts are:

• vulcan-abhinav
• vulcan-djacobs
• vulcan-jbhuang
• vulcan-lsd
• vulcan-metzler
• vulcan-rama
• vulcan-ramani
• vulcan-yaser
• vulcan-zwicker

$ sacctmgr show account format=account%20,description%30,organization%10
             Account                          Descr        Org
-------------------- ------------------------------ ----------
                 ...                            ...        ...
              vulcan                         vulcan     vulcan
      vulcan-abhinav   vulcan - abhinav shrivastava     vulcan
      vulcan-djacobs          vulcan - david jacobs     vulcan
      vulcan-jbhuang         vulcan - jia-bin huang     vulcan
          vulcan-lsd           vulcan - larry davis     vulcan
      vulcan-metzler         vulcan - chris metzler     vulcan
         vulcan-rama        vulcan - rama chellappa     vulcan
       vulcan-ramani     vulcan - ramani duraiswami     vulcan
        vulcan-yaser          vulcan - yaser yacoob     vulcan
      vulcan-zwicker      vulcan - matthias zwicker     vulcan
                 ...                            ...        ...

Faculty can manage this list of users via our Directory application in the Security Groups section. The security group that controls access has the prefix vulcan_ and then the faculty username. It will also list slurm://nexusctl.umiacs.umd.edu as the associated URI.

You can check your account associations by running the show_assoc command to see the accounts you are associated with. Please contact staff and include your faculty member in the conversation if you do not see the appropriate association.

$ show_assoc
      User          Account MaxJobs       GrpTRES                                                                              QOS
---------- ---------------- ------- ------------- --------------------------------------------------------------------------------
       ...              ...     ...                                                                                            ...
   abhinav          abhinav      48                           vulcan-cpu,vulcan-default,vulcan-high,vulcan-medium,vulcan-scavenger
   abhinav           vulcan      48                                       vulcan-cpu,vulcan-default,vulcan-medium,vulcan-scavenger
       ...              ...     ...                                                                                            ...

You can also see the total number of Track-able Resources (TRES) allowed for each account by running the following command. Please make sure you give the appropriate account that you are looking for. As shown below, there is a concurrent limit of 64 total GPUs for all users not in a contributing faculty group.

$ sacctmgr show assoc account=vulcan format=user,account,qos,grptres
      User    Account                  QOS       GrpTRES
---------- ---------- -------------------- -------------
               vulcan                        gres/gpu=64
                  ...                                ...

QoS

You need to decide the QOS to submit with which will set a certain number of restrictions to your job. If you do not specify a QoS when submitting your job using the --qos parameter, you will receive the vulcan-default QoS assuming you are using a Vulcan account.

The following sacctmgr command will list the current QOS. Either the vulcan-default, vulcan-medium, or vulcan-high QOS is required for the vulcan-dpart partition. Please note that only faculty accounts (see above) have access to the vulcan-high QoS.

The following example will show you the current limits that the QOS have.

$ show_qos
                Name     MaxWall                        MaxTRES MaxJobsPU MaxSubmitPU                      MaxTRESPU              GrpTRES
-------------------- ----------- ------------------------------ --------- ----------- ------------------------------ --------------------
                 ...         ...                            ...       ...         ...                            ...                  ...
       vulcan-medium  3-00:00:00       cpu=8,gres/gpu=2,mem=64G         2
         vulcan-high  1-12:00:00     cpu=16,gres/gpu=4,mem=128G         2
      vulcan-default  7-00:00:00       cpu=4,gres/gpu=1,mem=32G         2
    vulcan-scavenger  3-00:00:00     cpu=32,gres/gpu=8,mem=256G
        vulcan-janus  3-00:00:00    cpu=32,gres/gpu=10,mem=256G
       vulcan-exempt  7-00:00:00     cpu=32,gres/gpu=8,mem=256G         2
          vulcan-cpu  2-00:00:00                cpu=1024,mem=4T         4
    vulcan-exclusive 30-00:00:00
       vulcan-sailon  3-00:00:00     cpu=32,gres/gpu=8,mem=256G                                          gres/gpu=48
                 ...         ...                            ...       ...         ...                            ...                  ...

Storage

Vulcan has the following storage available. Please also review UMIACS Local Data Storage policies including any volume that is labeled as scratch.

Vulcan users can also request Nexus project allocations.

Home Directory

You have 20GB of storage available at /nfshomes/<username>. It has both Snapshots and Backups available if need be.

Home directories are intended to store personal or configuration files only. We encourage users to not share any data in their home directory.

Scratch Directories

Scratch data has no data protection including no snapshots and the data is not backed up. There are two types of scratch directories in the Vulcan compute infrastructure:

• Network scratch directory
• Local scratch directories

Network Scratch Directory

You are allocated 300GB of scratch space via NFS from /vulcanscratch/$username. It is not backed up or protected in any way. This directory is automounted so you will need to cd into the directory or request/specify a fully qualified file path to access this.

You may request a temporary increase of up to 500GB total space for a maximum of 120 days without any faculty approval by contacting staff@umiacs.umd.edu. Once the temporary increase period is over, you will be contacted and given a one-week window of opportunity to clean and secure your data before staff will forcibly remove data to get your space back under 300GB. If you need space beyond 500GB or for longer than 120 days, you will need faculty approval and/or a project directory.

This file system is available on all submission, data management, and computational nodes within the cluster.

Local Scratch Directories

Each computational node that you can schedule compute jobs on has one or more local scratch directories. These are always named /scratch0, /scratch1, etc. These are almost always more performant than any other storage available to the job. However, you must stage their data within the confine of their job and stage the data out before the end of their job.

These local scratch directories have a tmpwatch job which will delete unaccessed data after 90 days, scheduled via maintenance jobs to run once a month at 1am. Different nodes will run the maintenance jobs on different days of the month to ensure the cluster is still highly available at all times. Please make sure you secure any data you write to these directories at the end of your job.

Datasets

We have read-only dataset storage available at /fs/vulcan-datasets. If there are datasets that you would like to see curated and available, please see this page.

The following is the list of datasets available:

Dataset	Path
3D-FRONT	/fs/vulcan-datasets/3d-front
3D-FUTURE	/fs/vulcan-datasets/3d-future
Action Genome	/fs/vulcan-datasets/AG
ActivityNet	/fs/vulcan-datasets/ActivityNet
CATER	/fs/vulcan-datasets/CATER
COVID-DA	/fs/vulcan-datasets/COVID-DA
CelebA	/fs/vulcan-datasets/CelebA
CelebA-HQ	/fs/vulcan-datasets/CelebA-HQ
CelebAMask-HQ	/fs/vulcan-datasets/CelebAMask-HQ
Charades	/fs/vulcan-datasets/Charades
CharadesEgo	/fs/vulcan-datasets/CharadesEgo
CIFAR10	/fs/vulcan-datasets/cifar-10-python
CIFAR100	/fs/vulcan-datasets/cifar-100-python
CityScapes	/fs/vulcan-datasets/cityscapes
COCO	/fs/vulcan-datasets/coco
Conceptual Captions	/fs/vulcan-datasets/conceptual_captions
CUB	/fs/vulcan-datasets/CUB
DeepFashion	/fs/vulcan-datasets/DeepFashion
Digits	/fs/vulcan-datasets/digits_full
Edges2handbags	/fs/vulcan/datasets/edges2handbags
Edges2shoes	/fs/vulcan/datasets/edges2shoes
EGTEA	/fs/vulcan/datasets/EGTEA
emnist	/fs/vulcan-datasets/emnist
EPIC Kitchens 2018	/fs/vulcan-datasets/Epics-kitchen-2018
EPIC Kitchens 2020	/fs/vulcan-datasets/EPIC-Kitchens-2020
Facades	/fs/vulcan/datasets/facades
from_games (GTA5)	/fs/vulcan-datasets/from_games
FFHQ	/fs/vulcan-datasets/ffhq-dataset
FineGym	/fs/vulcan-datasets/FineGym
Google Landmarks Dataset v2	/fs/vulcan-datasets/google-landmark-v2
HAA500	/fs/vulcan-datasets/haa500
HICO	/fs/vulcan-datasets/HICO
HMDB51	/fs/vulcan-datasets/HMDB51
Honda_100h	/fs/vulcan-datasets/honda_100h
HPatches	/fs/vulcan-datasets/HPatches
Human3.6M	/fs/vulcan-datasets/human3.6
IM2GPS (test only)	/fs/vulcan-datasets/im2gps
ImageNet	/fs/vulcan-datasets/imagenet
iNaturalist Dataset 2021	/fs/vulcan-datasets/inat_comp_2021
InteriorNet	/fs/vulcan-datasets/InteriorNet
Kinetics-400	/fs/vulcan-datasets/Kinetics-400
Labelled Faces in the Wild	/fs/vulcan-datasets/lfw
LibriSpeech	/fs/vulcan-datasets/LibriSpeech
LSUN	/fs/vulcan-datasets/LSUN
LVIS	/fs/vulcan-datasets/LVIS
Maps	/fs/vulcan-datasets/maps
Matterport3D	/fs/vulcan-datasets/Matterport3D
MegaDepth	/fs/vulcan-datasets/MegaDepth
MineRL	/fs/vulcan-datasets/MineRL
Mini-ImageNet	/fs/vulcan-datasets/miniImagenet
MIT Indoor	/fs/vulcan-datasets/mit_indoor
MIT Places	/fs/vulcan-datasets/mit_places
Multi-PIE Face	/fs/vulcan-datasets/multipie
Night2day	/fs/vulcan-datasets/night2day
ObjectNet3D	/fs/vulcan-datasets/ObjectNet3D
Occluded Video Instance Segmentation	/fs/vulcan-datasets/ovis-2021
Office	/fs/vulcan-datasets/office
Office-Home	/fs/vulcan-datasets/office_home
omniglot	/fs/vulcan-datasets/omniglot
OOPS	/fs/vulcan-datasets/OOPS
OpenImagesv4	/fs/vulcan-datasets/OpenImagesv4
PartNet	/fs/vulcan-datasets/PartNet
Pascal VOC	/fs/vulcan-datasets/pascal_voc
PIC (HOI-A)	/fs/vulcan-datasets/PIC
PubLayNet	/fs/vulcan-datasets/PubLayNet
Replica	/fs/vulcan-datasets/Replica
ScanNet	/fs/vulcan-datasets/ScanNet
ShapeNetCore.v2	/fs/vulcan-datasets/ShapeNetCore.v2
Something-Something-V1	/fs/vulcan-datasets/SomethingV1
Something-Something-V2	/fs/vulcan-datasets/SomethingV2
SYNTHIA-RAND-CITYSCAPES	/fs/vulcan-datasets/SYNTHIA-RAND-CITYSCAPES
TAPOS	/fs/vulcan-datasets/TAPOS
Tiny ImageNet	/fs/vulcan-datasets/tiny_imagenet
Tumblr GIF Description	/fs/vulcan-datasets/TGIF
Thingi10K	/fs/vulcan-datasets/Thingi10K
UCF101	/fs/vulcan-datasets/UCF101
VirtualHomes	/fs/vulcan-datasets/VirtualHomes
visda17	/fs/vulcan-datasets/visda17
visda17_openset	/fs/vulcan-datasets/VISDA
visda19	/fs/vulcan-datasets/visda
Visual Genome	/fs/vulcan-datasets/VG
Visual Relationship Detection	/fs/vulcan-datasets/VRD
VOCdevkit	/fs/vulcan-datasets/VOCdevkit
VoxCeleb2	/fs/vulcan-datasets/VoxCeleb2
WILDS	/fs/vulcan-datasets/WILDS
xView2	/fs/vulcan-datasets/xView2
YCB Object Models	/fs/vulcan-datasets/YCB
YouTube8M	/fs/vulcan-datasets/YouTube8M
YouTubeVIS-2019	/fs/vulcan-datasets/YouTubeVIS-2019
YouTubeVIS-2021	/fs/vulcan-datasets/YouTubeVIS-2021

Project Storage

Users within the Vulcan compute infrastructure can request project based allocations for up to 10TB for up to 180 days by contacting staff with approval from the Vulcan faculty manager (Dr. Shrivastava). These allocations will be available from /fs/vulcan-projects under a name that you provide when you request the allocation. Near the end of the allocation period, staff will contact you and ask if you would like to renew the allocation for up to another 180 days (requires re-approval from Dr. Shrivastava). If you are no longer in need of the storage allocation, you will need to relocate all desired data within two weeks of the end of the allocation period. Staff will then remove the allocation. If you or the original faculty approver do not respond to staff's request or within one month of the end of the allocation period, staff will remove the allocation.

This data, by default, will be backed up nightly and have a limited snapshot schedule (1 daily snapshot). Upon request, staff can both exclude the data from backups and/or disable snapshots on the project storage volume. We currently have 100TB total to support these projects which includes the snapshot data for this volume.

Object Storage

All Vulcan users can request project allocations in the UMIACS Object Store. Please email staff@umiacs.umd.edu with a short project name and the amount of storage you will need to get started.

An example on how to use the umobj command line utilities can be found here. A full set of documentation for the utilities can be found on the umobj Gitlab page.

Timeline

Each event will be completed within the timeframe specified.

Date	Event
July 21st 2023	Two compute nodes vulcan11 and vulcan12 are moved into Nexus so submission can be tested
August 17th 2023, 5-8pm	All other standalone Vulcan cluster compute nodes are moved into Nexus in corresponding vulcan- named partitions
September 21st 2023, 5-8pm	vulcansub00.umiacs.umd.edu and vulcansub01.umiacs.umd.edu are taken offline

Migration

Home Directories

The Nexus uses NFShomes home directories - if your UMIACS account was created before February 22nd, 2023, you were using /cfarhomes/<username> as your home directory on the standalone Vulcan cluster. While /cfarhomes is available on Nexus, your shell initialization scripts from it will not automatically load. Please copy over anything you need to your /nfshomes/<username> directory at your earliest convenience, as /cfarhomes may be retired in the coming year.