Greetings All, I have come across a strange scenario using zfs 0.6.4.2-1 and Lustre 2.8.0.
In a nutshell, when we delete items from lustre using rm, the files/dirs are seemingly removed, but the space is not freed on the underlying zfs dataset/zpool. We have unmounted the OST/dataset, exported the zpool, and even rebooted the server altogether. The space is never freed. I have read through many of the issues logged about this on https://github.com/zfsonlinux; many folks have reclaimed the space once they unmount/remount, and/or export/import. As noted above, this has no impact on our dataset/zpool. We currently have a zpool scrub running, and expect this to complete in the next few hours. We DO have zfs compression enabled, and we are using ZFS quota and reservations for the associated OST/dataset. We have copied the dataset to an entirely different zpool (zfs send/receive), and then mounted as native ZFS to poke around. In doing so, we located some of the "broken path" files that were of decent size (4GB) and went a head and removed them with rm. These files were/are ones that we see with the ??? in the path output from zdb. After removing the files, the space was almost immediately freed from the dataset/zpool. Here is an example of a directory and a file from the zdb output. Object lvl iblk dblk dsize lsize %full type 136 2 16K 16K 9.00K 32K 100.00 ZFS directory 144 bonus System attributes dnode flags: USED_BYTES USERUSED_ACCOUNTED dnode maxblkid: 1 path ???<object#136> uid 0 gid 0 atime Wed Dec 31 19:00:00 1969 mtime Wed Dec 31 19:00:00 1969 ctime Wed Dec 31 19:00:00 1969 crtime Thu Mar 10 12:04:52 2016 gen 1020298 mode 40755 size 2 parent 1 links 1 pflags 0 rdev 0x0000000000000000 Fat ZAP stats: Pointer table: 1024 elements zt_blk: 0 zt_numblks: 0 zt_shift: 10 zt_blks_copied: 0 zt_nextblk: 0 ZAP entries: 2 Leaf blocks: 1 Total blocks: 2 zap_block_type: 0x8000000000000001 zap_magic: 0x2f52ab2ab zap_salt: 0x3fdbcd9ab9 Leafs with 2^n pointers: 9: 1 * Blocks with n*5 entries: 0: 1 * Blocks n/10 full: 1: 1 * Entries with n chunks: 3: 2 ** Buckets with n entries: 0: 510 **************************************** 1: 2 * 0 = 38711 (type: not specified) feb93 = 281474976687710 (type: 15 (invalid)) Object lvl iblk dblk dsize lsize %full type 138 1 16K 128K 128K 128K 100.00 ZFS plain file 220 bonus System attributes dnode flags: USED_BYTES USERUSED_ACCOUNTED dnode maxblkid: 0 path ???<object#138> uid 0 gid 0 atime Wed Dec 31 19:00:00 1969 mtime Wed Dec 31 19:00:00 1969 ctime Wed Dec 31 19:00:00 1969 crtime Thu Mar 10 12:04:52 2016 gen 1020298 mode 100644 size 8 parent 0 links 1 pflags 0 rdev 0x0000000000000000 SA xattrs: 76 bytes, 1 entries trusted.lma = \000\000\000\000\000\000\000\000\003\000\000\000\002\000\000\000\000\000\000\000\000\000\000\000 Can anyone advise on some next steps troubleshooting, or previous experiences that are similar to ours? Thanks, Tom
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