[slurm-users] job is pending but resources are available

[Adam Xu]

Hi All,

OS: Rocky Linux 8.4

slurm version: 20.11.7

the partition's name is apollo. the node's name is apollo too. the node 
has 36 cpu cores and 8GPUs in it.

partition info

$ scontrol show partition apollo
PartitionName=apollo
    AllowGroups=ALL AllowAccounts=ALL AllowQos=ALL
    AllocNodes=ALL Default=NO QoS=N/A
    DefaultTime=NONE DisableRootJobs=NO ExclusiveUser=NO GraceTime=0 
Hidden=NO
    MaxNodes=UNLIMITED MaxTime=UNLIMITED MinNodes=0 LLN=NO 
MaxCPUsPerNode=UNLIMITED
    Nodes=apollo
    PriorityJobFactor=1 PriorityTier=1 RootOnly=NO ReqResv=NO 
OverSubscribe=YES:36
    OverTimeLimit=NONE PreemptMode=OFF
    State=UP TotalCPUs=36 TotalNodes=1 SelectTypeParameters=NONE
    JobDefaults=(null)
    DefMemPerNode=UNLIMITED MaxMemPerNode=UNLIMITED

node info

$ scontrol show node apollo
NodeName=apollo Arch=x86_64 CoresPerSocket=18
    CPUAlloc=28 CPUTot=36 CPULoad=7.02
    AvailableFeatures=(null)
    ActiveFeatures=(null)
    Gres=gpu:v100:8,mps:v100:800
    NodeAddr=apollo NodeHostName=apollo Version=20.11.7
    OS=Linux 4.18.0-305.19.1.el8_4.x86_64 #1 SMP Wed Sep 15 19:12:32 UTC 
2021
    RealMemory=1 AllocMem=0 FreeMem=47563 Sockets=2 Boards=1
    State=MIXED ThreadsPerCore=1 TmpDisk=0 Weight=1 Owner=N/A MCS_label=N/A
    Partitions=apollo
    BootTime=2021-09-20T23:43:49 SlurmdStartTime=2021-10-12T16:55:44
    CfgTRES=cpu=36,mem=1M,billing=36
    AllocTRES=cpu=28
    CapWatts=n/a
    CurrentWatts=0 AveWatts=0
    ExtSensorsJoules=n/s ExtSensorsWatts=0 ExtSensorsTemp=n/s
    Comment=(null)

Now I have 7 jobs running but when I submit 8th job, the status of the 
job is pending beacuse Resources.

$ squeue
              JOBID PARTITION     NAME     USER ST       TIME NODES 
NODELIST(REASON)
                879    apollo    do.sh zhining_ PD       0:00 1 (Resources)
                489    apollo    do.sh zhining_  R 13-12:50:45 1 apollo
                490    apollo    do.sh zhining_  R 13-12:41:00 1 apollo
                592    apollo runme-gp junwen_f  R 4-12:42:31 1 apollo
                751    apollo runme-gp junwen_f  R 1-12:48:20 1 apollo
                752    apollo runme-gp junwen_f  R 1-12:48:10 1 apollo
                871    apollo runme-gp junwen_f  R    7:13:45 1 apollo
                872    apollo runme-gp junwen_f  R    7:12:42 1 apollo

$ scontrol show job 879
JobId=879 JobName=do.sh
    UserId=zhining_wan(1001) GroupId=zhining_wan(1001) MCS_label=N/A
    Priority=4294900882 Nice=0 Account=(null) QOS=(null)
    JobState=PENDING Reason=Resources Dependency=(null)
    Requeue=1 Restarts=0 BatchFlag=1 Reboot=0 ExitCode=0:0
    RunTime=00:00:00 TimeLimit=UNLIMITED TimeMin=N/A
    SubmitTime=2021-10-12T16:29:29 EligibleTime=2021-10-12T16:29:29
    AccrueTime=2021-10-12T16:29:29
    StartTime=2021-10-12T21:17:41 EndTime=Unknown Deadline=N/A
    SuspendTime=None SecsPreSuspend=0 LastSchedEval=2021-10-12T21:17:39
    Partition=apollo AllocNode:Sid=sms:1281191
    ReqNodeList=(null) ExcNodeList=(null)
    NodeList=(null) SchedNodeList=apollo
    NumNodes=1-1 NumCPUs=4 NumTasks=4 CPUs/Task=1 ReqB:S:C:T=0:0:*:*
    TRES=cpu=4,node=1,billing=4
    Socks/Node=* NtasksPerN:B:S:C=0:0:*:* CoreSpec=*
    MinCPUsNode=1 MinMemoryNode=0 MinTmpDiskNode=0
    Features=(null) DelayBoot=00:00:00
    OverSubscribe=YES Contiguous=0 Licenses=(null) Network=(null)
Command=/home/zhining_wan/job/2021/20210603_ctla4_double_bilayer/final_pdb_minimize/amber/nolipid/test/do.sh
WorkDir=/home/zhining_wan/job/2021/20210603_ctla4_double_bilayer/final_pdb_minimize/amber/nolipid/test
StdErr=/home/zhining_wan/job/2021/20210603_ctla4_double_bilayer/final_pdb_minimize/amber/nolipid/test/slurm-879.out
    StdIn=/dev/null
StdOut=/home/zhining_wan/job/2021/20210603_ctla4_double_bilayer/final_pdb_minimize/amber/nolipid/test/slurm-879.out
    Power=
    TresPerNode=gpu:1
    NtasksPerTRES:0

After running 7 jobs, the node has 8 cpu cores and 1 gpu left, so I can 
be sure that the remaining resources are sufficient. but why the job is 
pending with reason "Resources"?

-- 
Adam Xu