On 2011-04-18, at 8:15 PM, Johnny R wrote: > Excuse me for my ignorance,I'm a newbie in Lustre,and I'm planning to > organize the inodes in the MDS used B-tree. > And now I am confused about how things are worked in Lustre.
Lustre itself doesn't handle directly the on-disk layout for directories. That is done using a patched version of ext4, so if you want to do any development with b-trees you can mostly just do it against ext4. That said, you should look at the "IAM" patch in ldiskfs as a starting point. It is essentially implementing btree layout for ext4, but it was never put into production because it didn't include e2fsck support, changed the on-disk layout, and the benefits of it are largely achievable with in-kernel changes. See also the recent presentation about metadata server scaling with pdirops for ext4 http://wiki.whamcloud.com/download/attachments/7634983/Lustre-MDPI.pdf?version=1&modificationDate=1302720127630 slides 16-18, and the patch in Gerrit at http://review.whamcloud.com/#change,375. This is more likely to be the path forward, since it avoids any need to change the underlying filesystem format. > I use version 1.4.8,and there is fs.h fs.c inode.h inode.c in the Lustre > source files. Sorry, but any work done on Lustre 1.4 is completely pointless. You should start with 1.8.5 or the pre-1.8.6 code from git.lustre.org. If you are doing anything for actual inclusion into future Lustre releases, it is best to do it from the pre-2.1 code at git.whamcloud.com. > But when I look up the Lustre arrchives,I find that Lustre seems to use > llite to manage the inode part. > Looking forward to your answers. > > Johnny R > _______________________________________________ > Lustre-discuss mailing list > [email protected] > http://lists.lustre.org/mailman/listinfo/lustre-discuss Cheers, Andreas -- Andreas Dilger Principal Engineer Whamcloud, Inc. _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
