Thanks Andreas. Is this documented anywhere? We are facing inode shortage problems on our filesystem and I would like to show this to my professors. The reason why this is occurring is..
I checked the operations manual and Lustre "inter galactic" file system but no luck of this issue. TIA On Wed, Aug 20, 2008 at 1:55 AM, Andreas Dilger <[EMAIL PROTECTED]> wrote: > On Aug 19, 2008 20:27 -0400, Mag Gam wrote: >> Yes, I have looked thru the lists but I could not really get this >> question answered. tune2fs is a ext2/3 setting, and I though each file >> I create on a Lustre filesystem an inode gets created on the MDS and >> the OST as an object. >> >> But, I don't understand how there is that much of a space discrepancy. > > The reason for this discrepancy is because of "safety". It is possible > that the striping is too large to fit into the inode, so it needs an > external block. If that is needed for every remaining inode on the MDS > then the limit on the number of files created is equal to the number of > free blocks on the MDS. In order to avoid over-stating the number of > possible files that can be created (sometimes important to e.g. RPM > or regression tests), "df" and "lfs df" will return min(free inodes, > free blocks) for the inode count. > > If (as usually happens) inodes are created that do not need external blocks > to store the striping information then more inodes "appear" (i.e. as > "IUsed" increases so does "Inodes" and "IFree" stays constant). > >> Also, how does striping account for in inodes? Lets say I stipe a file >> on 4 OSTs, I suppose 5 (1 for MDS, 4 for OSTs) inodes are occupied, >> correct? > > Yes, though each of the inodes are in different filesystems. > >> On Tue, Aug 19, 2008 at 4:30 PM, Brian J. Murrell <[EMAIL PROTECTED]> wrote: >> > On Sun, 2008-08-17 at 15:50 -0700, Mag Gam wrote: >> >> My departments Lustre's lfs df -i looks like this >> >> >> >> UUID Inodes IUsed IFree IUse% Mounted on >> >> xfs001-MDT0000_UUID 82565322 19073586 63491736 23% >> >> /xfs/engine1/xfs001[MDT:0] >> >> xfs001-OST0000_UUID 41943040 5076445 36866595 12% >> >> /xfs/engine1/xfs001[OST:0] >> >> xfs001-OST0001_UUID 41943040 3735715 38207325 8% >> >> /xfs/engine1/xfs001[OST:1] >> >> xfs001-OST0002_UUID 41943040 4784447 37158593 11% >> >> /xfs/engine1/xfs001[OST:2] >> >> xfs001-OST0003_UUID 41943040 4556627 37386413 10% >> >> /xfs/engine1/xfs001[OST:3] >> >> >> >> filesystem summary: 82565322 19073586 63491736 23% >> >> /xfs/engine1/xfs001 >> >> >> >> >> >> Is it safe to say, " >> >> My MDT has "19073586" 19 million inodes free? or should I consider. >> >> >> >> However, when I check my inode count on my mds using tune2fs it reports >> >> this. >> >> Inode count: 524288000 >> >> Free inodes: 505214414 >> >> >> >> Am I missing something? >> > >> > Yes. lfs df does not simply report the free inodes on the MDT. It's >> > more complicated than that. This has been discussed either here or in a >> > bugzilla bug (don't recall which). I don't recall the bug or when the >> > lustre-discussion was, offhand, but a search should not be terribly >> > difficult to find the answer. >> > >> > b. >> > >> > >> > _______________________________________________ >> > Lustre-discuss mailing list >> > Lustre-discuss@lists.lustre.org >> > http://lists.lustre.org/mailman/listinfo/lustre-discuss >> > >> > >> _______________________________________________ >> Lustre-discuss mailing list >> Lustre-discuss@lists.lustre.org >> http://lists.lustre.org/mailman/listinfo/lustre-discuss > > Cheers, Andreas > -- > Andreas Dilger > Sr. Staff Engineer, Lustre Group > Sun Microsystems of Canada, Inc. > > _______________________________________________ Lustre-discuss mailing list Lustre-discuss@lists.lustre.org http://lists.lustre.org/mailman/listinfo/lustre-discuss