Nexus/CBCB
The Nexus scheduler houses CBCB's new computational partition. Only CBCB lab members are able to run non-interruptible jobs on these nodes.
Submission Nodes
You can SSH to nexuscbcb.umiacs.umd.edu to log in to a submission host.
If you store something in a local directory (/tmp, /scratch0) on one of the two submission hosts, you will need to connect to that same submission host to access it later. The actual submission hosts are:
nexuscbcb00.umiacs.umd.edunexuscbcb01.umiacs.umd.edu
Nodes
All nodes in CBCB-owned partitions (see below section) owned by CBCB faculty are named in the format cbcb##. The sets of nodes are:
- 22 nodes that were purchased in October 2022 with center-wide funding. They are cbcb[00-21].
- 4 nodes from the previous standalone CBCB cluster that moved in as of Summer 2023. They are cbcb[22-25].
- A few additional nodes purchased by Dr. Heng Huang since then. They are all remaining 'cbcb' named nodes.
| Nodenames | Quantity | CPU cores per node (CPUs) | Memory per node (type) | Local storage per node (type/location) | GPUs per node (type) |
|---|---|---|---|---|---|
| cbcb[00-21] | 22 | 32 (Dual AMD EPYC 7313) | ~2TB (DDR4 3200MHz) | ~350GB (SATA SSD /scratch0), ~2TB (NVMe SSD /scratch1) | 0 |
| cbcb22 | 1 | 28 (Dual Intel Xeon E5-2680 v4) | ~768GB (DDR4 2400MHz) | ~650GB (SATA SSD /scratch0) | 0 |
| cbcb[23-24] | 2 | 24 (Dual Intel Xeon E5-2650 v4) | ~256GB (DDR4 2400MHz) | ~800GB (SATA SSD /scratch0) | 0 |
| cbcb25 | 1 | 24 (Dual Intel Xeon E5-2650 v4) | ~256GB (DDR4 2400MHz) | ~1.4TB (SATA SSD /scratch0) | 2 (1x NVIDIA GeForce GTX 1080 Ti, 1x NVIDIA GeForce RTX 2080 Ti) |
| cbcb26 | 1 | 128 (Dual AMD EPYC 7763) | ~512GB (DDR4 3200MHz) | ~3.4TB (NVMe SSD /scratch0), ~14TB (NVMe SSD /scratch1) | 8 (NVIDIA RTX A5000) |
| cbcb27 | 1 | 64 (Dual AMD EPYC 7513) | ~256GB (DDR4 3200MHz) | ~3.4TB (SATA SSD /scratch0), ~3.5TB (NVMe SSD /scratch1) | 8 (NVIDIA RTX A6000) |
| cbcb[28-29] | 2 | 32 (Dual AMD EPYC 9124) | ~768GB (DDR5 4800MHz) | ~350GB (SATA SSD /scratch0), ~7TB (NVMe SSD /scratch1) | 8 (NVIDIA RTX 6000 Ada Generation) |
| Total | 30 | 1060 (various) | ~49TB (various) | ~94TB (various) | 34 (various) |
Here is the listing of nodes as shown by the Slurm alias show_nodes (again, all nodes are named in the format cbcb##):
[root@nexusctl00 ~]# show_nodes | grep cbcb NODELIST CPUS MEMORY AVAIL_FEATURES GRES STATE cbcb00 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb01 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb02 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb03 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb04 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb05 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb06 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb07 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb08 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb09 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb10 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb11 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb12 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb13 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb14 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb15 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb16 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb17 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb18 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb19 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb20 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb21 32 2061175 rhel8,Zen,EPYC-7313 (null) idle cbcb22 28 771245 rhel8,Xeon,E5-2680 (null) idle cbcb23 24 255150 rhel8,Xeon,E5-2650 (null) idle cbcb24 24 255150 rhel8,Xeon,E5-2650 (null) idle cbcb25 24 255278 rhel8,Xeon,E5-2650,Pascal,Turi gpu:rtx2080ti:1,gpu:gtx1080ti:1 idle cbcb26 128 513243 rhel8,Zen,EPYC-7763,Ampere gpu:rtxa5000:8 idle cbcb27 64 255167 rhel8,Zen,EPYC-7513,Ampere gpu:rtxa6000:8 idle cbcb28 32 771166 rhel8,Zen,EPYC-9124,Ada gpu:rtx6000ada:8 idle cbcb29 32 771166 rhel8,Zen,EPYC-9124,Ada gpu:rtx6000ada:8 idle
Partitions
There is only one partition available to general CBCB SLURM users. You must specify this partition when submitting your job.
- cbcb - This is the default partition. Job allocations on all nodes except those also in the below-mentioned partition are guaranteed.
There is one additional partition available solely to Dr. Heng Huang's sponsored accounts.
- cbcb-heng - This partition is for exclusive priority access to Dr. Huang's purchased GPU nodes. Job allocations are guaranteed.
QoS
CBCB users have access to all of the standard job QoSes in the cbcb partition using the cbcb account.
The additional job QoSes for the CBCB partition specifically are:
highmem: Allows for significantly increased memory to be allocated.huge-long: Allows for longer jobs using higher overall resources.
Please note that the partition has a GrpTRES limit of 100% of the available cores/RAM on the partition-specific nodes in aggregate plus 50% of the available cores/RAM on legacy## nodes in aggregate, so your job may need to wait if all available cores/RAM (or GPUs) are in use.
Jobs
You will need to specify --partition=cbcb and --account=cbcb to be able to submit jobs to the CBCB partition.
[username@nexuscbcb00:~ ] $ srun --pty --ntasks=16 --mem=2000G --qos=highmem --partition=cbcb --account=cbcb --time 1-00:00:00 bash srun: job 218874 queued and waiting for resources srun: job 218874 has been allocated resources [username@cbcb00:~ ] $ scontrol show job 218874 JobId=218874 JobName=bash UserId=username(1000) GroupId=username(21000) MCS_label=N/A Priority=897 Nice=0 Account=cbcb QOS=highmem JobState=RUNNING Reason=None Dependency=(null) Requeue=1 Restarts=0 BatchFlag=0 Reboot=0 ExitCode=0:0 RunTime=00:00:06 TimeLimit=1-00:00:00 TimeMin=N/A SubmitTime=2022-11-18T11:13:56 EligibleTime=2022-11-18T11:13:56 AccrueTime=2022-11-18T11:13:56 StartTime=2022-11-18T11:13:56 EndTime=2022-11-19T11:13:56 Deadline=N/A PreemptEligibleTime=2022-11-18T11:13:56 PreemptTime=None SuspendTime=None SecsPreSuspend=0 LastSchedEval=2022-11-18T11:13:56 Scheduler=Main Partition=cbcb AllocNode:Sid=nexuscbcb00:25443 ReqNodeList=(null) ExcNodeList=(null) NodeList=cbcb00 BatchHost=cbcb00 NumNodes=1 NumCPUs=16 NumTasks=16 CPUs/Task=1 ReqB:S:C:T=0:0:*:* TRES=cpu=16,mem=2000G,node=1,billing=2266 Socks/Node=* NtasksPerN:B:S:C=0:0:*:* CoreSpec=* MinCPUsNode=1 MinMemoryNode=2000G MinTmpDiskNode=0 Features=(null) DelayBoot=00:00:00 OverSubscribe=OK Contiguous=0 Licenses=(null) Network=(null) Command=bash WorkDir=/nfshomes/username Power=
Storage
CBCB still has its current storage allocation in place. All data filesystems that were available in the standalone CBCB cluster are also available in Nexus. Please note about the change in your home directory in the migration section below.
CBCB users can also request Nexus project allocations.
Migration
Home Directories
The Nexus uses NFShomes home directories and not /cbcbhomes/<USERNAME>. As part of the process of migrating into Nexus, you may want (or need) to copy any shell customization from your existing /cbcbhomes to your /nfshomes. To make this transition easier, /cbcbhomes is available to the Nexus CBCB submission nodes.
Operating System / Software
CBCB's standalone cluster submission and compute nodes were running RHEL7. Nexus is exclusively running RHEL8, so any software you may have compiled may need to be re-compiled to work correctly in this new environment. The CBCB module tree for RHEL8 may not yet be fully populated with RHEL8 software. If you do not see the modules you need, please reach out to the CBCB software maintainers.