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Re: [Condor-users] Site-wide want_remote_io=false possible?

Carsten Aulbert wrote:

brief questions around want_remote_io:

(1) Is it possible to enable this site-wide, e.g. change the default
setting to False. I guess it is but so far I have failed to find that,
how can that be done?

Well, you can tell condor_submit to add this setting by default into each submit file. If you are able to edit the condor_config file(s) of all machines where your users run condor_submit, the following entry should do the job:

   SUBMIT_EXPRS = WantRemoteIO=True

(the Manual has more details on SUBMIT_EXPRS)

(2) On our system users have their home file system under NFS and then
can also use a local directory which is also automountable via NFS. Does
the user need to avoid writing to the local disk under all circumstances
when want_remote_io is set to false?

No, they can write to local disk, but realize in standard universe if they write to local disk then Condor will not do any work to send the files back to the submit machine; so writing to local disk is fine for temporary files (who will clean them up?) but not such a good idea for output files.

The reason why we want to disable that is that our submit machines are
under very heavy load when large standard usinverse jobs are run and we
suspect remote io playing a key role here.

Maybe your UID_DOMAIN and FILESYSTEM_DOMAIN settings are incorrect?

See the section on shared filesystem settings for Condor in the Manual at URL:

Basically, in standard universe if the UID_DOMAIN and the FILESYSTEM_DOMAIN of between the submit and execute machine are both equal, then Condor should use the shared filesystem to access the file and not use remote I/O. Does your submit machine and execute machine mount the same shared filesystems on the same mount points? If yes, then I would make sure the shared filesystem settings are correct and then Condor should "do the right thing(tm)" and not require you to disable remote I/O all the time.

Thanks in advance

Sure, hope the above is helpful,