Revisiting this thread after 2 months... On 01/12/2011 05:45 PM, Robin Humble wrote: > On Thu, Jan 06, 2011 at 05:42:24PM -0700, [email protected] wrote: >> I am looking for more information regarding the "size on MDS" feature as >> it exists for lustre-1.8.x. Testing on our system (which started out as >> 1.6.6 and is now 1.8.x) indicates that there are many files which do not >> have the size information stored on the MDT. So, my basic question: >> under what conditions will the "size hint" attribute be updated? Is >> there any way to force the MDT to query the OSTs and update it's >> information? > > atime (and the MDT size hint) wasn't being updated for most of the 1.8 > series due to this bug: > https://bugzilla.lustre.org/show_bug.cgi?id=23766 > the atime fix is now in 1.8.5, but I'm not sure if anyone has verified > whether or not the MDT size hint is now behaving as originally intended.
I wanted to report back that I applied the patch in that bug and it appears as though the MDT size hint is working. This is tested with lustre-1.8.4.ddn2.2 and linux-2.6.18-194.32.1 on the MDS. > BTW, once you have 1.8.5 on the MDS, then a hack to populate the MDT > size hints might be to read 4k from every file in the system. that > should update atime and the size hint. please let us know if this works. > Yes, performing "ls -l" on the file from the client was not sufficient. The size hint was updated on the MDS after reading 1k from the file on the client. Running 'du --apparent-size' now reports the exact same value on the MDT snapshot as on the client. -Nathan _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
