[slurm-users] Defining an empty partition

[Tina Friedrich]

Yeah, I had that problem as well (trying to set up a partition that 
didn't have any nodes - they're not here yet).

I figured that one can have partitions with nodes that don't exist, 
though. As in, not even in DNS.

I currently have this:

[arc-slurm ~]$ sinfo
PARTITION AVAIL  TIMELIMIT  NODES  STATE NODELIST
short        up   12:00:00      1  down* arc-c023
short        up   12:00:00      1  alloc arc-c001
short        up   12:00:00     43   idle arc-c[002-022,024-045]
medium       up 2-00:00:00      0    n/a
long*        up   infinite      0    n/a

with medium & long partition containing nodes 'arc-c[046-297]':

PartitionName=medium
    AllowGroups=ALL AllowAccounts=ALL AllowQos=ALL
    AllocNodes=ALL Default=NO QoS=N/A
    DefaultTime=12:00:00 DisableRootJobs=NO ExclusiveUser=NO GraceTime=0 
Hidden=NO
    MaxNodes=UNLIMITED MaxTime=2-00:00:00 MinNodes=0 LLN=NO 
MaxCPUsPerNode=UNLIMITED
    Nodes=arc-c[046-297]...

which don't exist as of today:

[arc-slurm ~]$ host arc-c046
Host arc-c046 not found: 3(NXDOMAIN)

which - as you can see - simply ends up with SLURM showing the partition 
with no nodes.

So you could just put a dummy nodename in the slurm.conf file?

Tina


On 18/12/2020 11:13, Steve Brasier wrote:
> Having tried just not even defining any partitions you hit this this 
> <https://github.com/SchedMD/slurm/blob/master/src/common/node_conf.c#L383>check 
> which seems to ensure you can't create a cluster with no nodes. Is it 
> possible to create a control node without any compute nodes, e.g. as 
> part of a staged deployment?
>
> http://stackhpc.com/ <http://stackhpc.com/>
> Please note I work Tuesday to Friday.
>
>
> On Fri, 18 Dec 2020 at 10:56, Steve Brasier <steveb at stackhpc.com 
> <mailto:steveb at stackhpc.com>> wrote:
>
>     Hi all,
>
>     According to the relevant manpage
>     <https://slurm.schedmd.com/archive/slurm-20.02.5/slurm.conf.html>
>     it's possible to define an empty partition using "Nodes= ".
>
>     However this doesn't seem to work (slurm 20.2.05):
>
>     [centos at testohpc-login-0 ~]$ grep -n Partition /etc/slurm/slurm.conf
>     72:PriorityWeightPartition=1000
>     105:PartitionName=compute Default=YES MaxTime=86400 State=UP Nodes=
>
>     (note there is a space after that final "=" but I've tried both
>     with and without)
>
>     [centos at testohpc-login-0 ~]$ sinfo
>     sinfo: error: Parse error in file /etc/slurm/slurm.conf line 105:
>     " Nodes= "
>     sinfo: fatal: Unable to process configuration file
>
>     Is this a bug, or am I doing it wrong?
>
>     thanks for any suggestions
>
>     Steve
>
>     http://stackhpc.com/ <http://stackhpc.com/>
>     Please note I work Tuesday to Friday.
>