On Thu, 8 Sep 2016, William Hay wrote: ...
Remember tmpfs is not a ramdisk but the linux VFS layer without an attempt to provide real file system guarantees. It shouldn't be cached any more agressively than other filesystems under normal circumstances. Most of the arguments against it seem to be along the lines of "tmpfs uses swap therefore it must cause swapping" which doesn't seem to be the case.
You've lived with this in production for some time now, so I should bow to your judgement.
But wouldn't you see a big difference in the amount of I/O activity when a system sees a memory pressure, as non-tmpfs filesystems already have more of the data on disk at that point?
Mind you, given the memory utilisation on our clusters and the fact that we recently went large on memory in order to keep buying dual-rank DIMMs, maybe it's not something we'd see under most of our workloads.
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In general I'm fairly comfortable with using btrfs for data that doesn't need to be preserved in the long term (ie working storage or data that can be easily recreated) and it has some neat features. I use other filesystems for data that would take work to recreate or is worth backing up/restoring.
Good to know, I'll take another look
Not sure if you can chgrp a file to a group that doesn't have a quota on a filesystem with group quotas enabled.
Yep, you can on Linux. I can't easily see a tweak to fix this or a way of setting a default quota. Possibly one of the reasons I cannot remember seeing anyone using group quotas...
Being able to do so would make group quotas a pain to administer. However ,if you can, I'd be more worried about innocent subversion than malicious. Anything that did a copy from another filesystem or archive while attempting to preserve permissions could potentially break it.
... Yeah, too many loopholes. Bad idea. Cheers, Mark _______________________________________________ users mailing list users@gridengine.org https://gridengine.org/mailman/listinfo/users
