[Lustre-discuss] Running low on inodes

[Andreas Dilger]

On Apr 17, 2008  10:47 -0700, D. Marc Stearman wrote:
> One of our production servers was created with 245M inodes,  which  
> was enough at the time, but then we doubled the size of the file  
> system and are now running low on inodes (only 27M available), and  
> capacity-wise, we are only 60% full.  We ran out of inodes once  
> already, and did a purge to reduce the number of filesystems.
> 
> I would like to migrate all the data on the MDS to another lun on the  
> RAID controller.  I can format a new file system with more inodes and  
> move all the data on the MDS to the new file system.
> 
> Here is my question:  What tools are safe to use to copy all the MDS  
> data?  Are cp, tar, rsync, etc aware of all the EA data in ldiskfs?   
> Is there a lustre tool to copy all the information on the MDS over to  
> a new disk?

If you have a very recent (1.17 from FC8) it supports the --xattr option
to copy EAs.  Otherwise the recommended procedure is described in a KB
article in bugzilla - a search for "backup & restore" gives bug 5716.

Out of curiosity, how big is the MDS LUN, and how much free space is
on the MDS?  We could reduce the default bytes/inode on the MDS to avoid
this problem in the future.  On ZFS it will be a non-issue (dynamic inode
allocation).

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.