[lustre-discuss] Full OST, any way of avoiding it without hanging?

[Mohr Jr, Richard Frank (Rick Mohr)]

> On Jan 7, 2019, at 2:09 PM, Jason Williams <jasonw at jhu.edu> wrote:
> 
> One last question, How safe is lfs_migrate?  The man page on the installation says it's UNSAFE for possibly in-use files.  The lustre manual doesn't have the same warning and says something about it being a bit more integrated with the MDS.
> 
> http://doc.lustre.org/lustre_manual.xhtml#dbdoclet.lfs_migrate

I have not used lfs_migrate, so I don’t have any direct experience.  From what I have read online, the lfs_migrate script used to just do a copy/rename of the file.  But now it looks like the “lfs” command has a built-in “lfs migrate” subcommand which supports a “—block” option to prevent file access while the migration is happening.  So it might be safe to use.

Perhaps someone else on the list with more experience using this command could chime in.

--
Rick Mohr
Senior HPC System Administrator
National Institute for Computational Sciences
http://www.nics.tennessee.edu