Hi Alexander,
The error "can't find address for host cn7" would indicate a DNS
problem. What is the output of "host cn7" from the srun host li1?
How many network devices are in your subnet? It may be that the Linux
kernel is doing "ARP cache trashing" if the number of devices approaches
512. What is the result of "arp cn7"?
To fix ARP cache trashing look in my Slurm Wiki page
https://wiki.fysik.dtu.dk/niflheim/Slurm_configuration#configure-arp-cache-for-large-networks
Best regards,
Ole
On 5/29/19 3:00 PM, Alexander Åhman wrote:
Hi,
Have a very strange problem. The cluster has been working just fine
until one node died and now I can't submit jobs to 2 of the nodes using
srun from the login machine. Using sbatch works just fine and also if I
use srun from the same host as slurmctld.
All the other nodes works just fine as they always has, only 2 nodes are
experiencing this problem. Very strange...
Have checked network connectivity and DNS and that is OK. I can ping,
ssh to all nodes just fine. All nodes are identical and using Slurm 18.08.
Also tested to reboot the 2 nodes and slurmctld but still same problem.
[alex@li1 ~]$ srun -w cn7 hostname
srun: error: fwd_tree_thread: can't find address for host cn7, check
slurm.conf
srun: error: Task launch for 1088816.0 failed on node cn7: Can't find an
address, check slurm.conf
srun: error: Application launch failed: Can't find an address, check
slurm.conf
srun: Job step aborted: Waiting up to 32 seconds for job step to finish.
srun: error: Timed out waiting for job step to complete
[alex@li1 ~]$ srun -w cn6 hostname
cn6.ydesign.se
What is this error "can't find address for host" about? Have searched
the web but can't find any good information about what the problem is or
what to do to resolve it.
Any kind soul out there who knows what to do next?
