Our lfsck finished. It repair a lot and we have over 13 million files in lost+found to go through. I'll be writing a script to move these to somewhere accessible by the users and grouped by owner and probably date too (trying not to get too many files in a single directory). Thanks again for the help with this.
For the benefit of others, this is how we started our lfsck: [root@hpfs-fsl-mds1 hpfs3-eg3]# lctl set_param printk=+lfsck [root@hpfs-fsl-mds1 hpfs3-eg3]# lctl lfsck_start -M scratch-MDT0000 -o Started LFSCK on the device scratch-MDT0000: scrub layout namespace [root@hpfs-fsl-mds1 hpfs3-eg3]# It took most of the weekend to run. Here are the results. [root@hpfs-fsl-mds1 ~]# lctl lfsck_query -M scratch-MDT0000 layout_mdts_init: 0 layout_mdts_scanning-phase1: 0 layout_mdts_scanning-phase2: 0 layout_mdts_completed: 1 layout_mdts_failed: 0 layout_mdts_stopped: 0 layout_mdts_paused: 0 layout_mdts_crashed: 0 layout_mdts_partial: 0 layout_mdts_co-failed: 0 layout_mdts_co-stopped: 0 layout_mdts_co-paused: 0 layout_mdts_unknown: 0 layout_osts_init: 0 layout_osts_scanning-phase1: 0 layout_osts_scanning-phase2: 0 layout_osts_completed: 22 layout_osts_failed: 0 layout_osts_stopped: 0 layout_osts_paused: 0 layout_osts_crashed: 0 layout_osts_partial: 2 layout_osts_co-failed: 0 layout_osts_co-stopped: 0 layout_osts_co-paused: 0 layout_osts_unknown: 0 layout_repaired: 38587653 namespace_mdts_init: 0 namespace_mdts_scanning-phase1: 0 namespace_mdts_scanning-phase2: 0 namespace_mdts_completed: 1 namespace_mdts_failed: 0 namespace_mdts_stopped: 0 namespace_mdts_paused: 0 namespace_mdts_crashed: 0 namespace_mdts_partial: 0 namespace_mdts_co-failed: 0 namespace_mdts_co-stopped: 0 namespace_mdts_co-paused: 0 namespace_mdts_unknown: 0 namespace_osts_init: 0 namespace_osts_scanning-phase1: 0 namespace_osts_scanning-phase2: 0 namespace_osts_completed: 0 namespace_osts_failed: 0 namespace_osts_stopped: 0 namespace_osts_paused: 0 namespace_osts_crashed: 0 namespace_osts_partial: 0 namespace_osts_co-failed: 0 namespace_osts_co-stopped: 0 namespace_osts_co-paused: 0 namespace_osts_unknown: 0 namespace_repaired: 1429495 [root@hpfs-fsl-mds1 ~]# lctl get_param -n mdd.scratch-MDT0000.lfsck_layout name: lfsck_layout magic: 0xb1732fed version: 2 status: completed flags: param: all_targets,orphan last_completed_time: 1695615657 time_since_last_completed: 35014 seconds latest_start_time: 1695335260 time_since_latest_start: 315411 seconds last_checkpoint_time: 1695615657 time_since_last_checkpoint: 35014 seconds latest_start_position: 15 last_checkpoint_position: 1015668480 first_failure_position: 0 success_count: 2 repaired_dangling: 22199282 repaired_unmatched_pair: 0 repaired_multiple_referenced: 0 repaired_orphan: 13489715 repaired_inconsistent_owner: 2898656 repaired_others: 0 skipped: 0 failed_phase1: 0 failed_phase2: 1798679 checked_phase1: 369403698 checked_phase2: 15 run_time_phase1: 82842 seconds run_time_phase2: 0 seconds average_speed_phase1: 4459 items/sec average_speed_phase2: 15 objs/sec real_time_speed_phase1: N/A real_time_speed_phase2: N/A current_position: N/A [root@hpfs-fsl-mds1 ~]# lctl get_param -n mdd.scratch-MDT0000.lfsck_namespace name: lfsck_namespace magic: 0xa06249ff version: 2 status: completed flags: param: all_targets,orphan last_completed_time: 1695419689 time_since_last_completed: 231012 seconds latest_start_time: 1695335262 time_since_latest_start: 315439 seconds last_checkpoint_time: 1695419689 time_since_last_checkpoint: 231012 seconds latest_start_position: 15, N/A, N/A last_checkpoint_position: 1015668480, N/A, N/A first_failure_position: N/A, N/A, N/A checked_phase1: 315743757 checked_phase2: 231782 updated_phase1: 1429495 updated_phase2: 0 failed_phase1: 0 failed_phase2: 0 directories: 15911850 dirent_repaired: 0 linkea_repaired: 1429495 nlinks_repaired: 0 multiple_linked_checked: 1983873 multiple_linked_repaired: 0 unknown_inconsistency: 0 unmatched_pairs_repaired: 0 dangling_repaired: 0 multiple_referenced_repaired: 0 bad_file_type_repaired: 0 lost_dirent_repaired: 0 local_lost_found_scanned: 0 local_lost_found_moved: 0 local_lost_found_skipped: 0 local_lost_found_failed: 0 striped_dirs_scanned: 0 striped_dirs_repaired: 0 striped_dirs_failed: 0 striped_dirs_disabled: 0 striped_dirs_skipped: 0 striped_shards_scanned: 0 striped_shards_repaired: 0 striped_shards_failed: 0 striped_shards_skipped: 0 name_hash_repaired: 0 linkea_overflow_cleared: 0 agent_entries_repaired: 0 success_count: 2 run_time_phase1: 82885 seconds run_time_phase2: 1542 seconds average_speed_phase1: 3809 items/sec average_speed_phase2: 150 objs/sec average_speed_total: 3742 items/sec real_time_speed_phase1: N/A real_time_speed_phase2: N/A current_position: N/A [root@hpfs-fsl-mds1 ~]# And on a client, the resulting lost+found directory: [root@hpfs-fsl-lmon0 MDT0000]# pwd /scratch-lustre/.lustre/lost+found/MDT0000 [root@hpfs-fsl-lmon0 MDT0000]# time \ls | wc -l 13063930 real 15m20.604s user 2m38.186s sys 0m4.116s [root@hpfs-fsl-lmon0 MDT0000]# \ls | head [0x20000bdbe:0x1eae1:0x0]-R-0 [0x20000bdeb:0x12c3e:0x0]-R-0 [0x20001f801:0x296f:0x0]-R-0 [0x20001f801:0x57:0x0]-R-0 [0x20001f801:0x58:0x0]-R-0 [0x20001f805:0x1000:0x0]-R-0 [0x20001f805:0x100:0x0]-R-0 [0x20001f805:0x1001:0x0]-R-0 [0x20001f805:0x1002:0x0]-R-0 [0x20001f805:0x1003:0x0]-R-0 [root@hpfs-fsl-lmon0 MDT0000]# ls -l [0x20000bdbe:0x1eae1:0x0]-R-0 -r-------- 1 damocles_runner damocles 3162 Sep 24 14:45 [0x20000bdbe:0x1eae1:0x0]-R-0 [root@hpfs-fsl-lmon0 MDT0000]# From: lustre-discuss <lustre-discuss-boun...@lists.lustre.org> on behalf of "Vicker, Darby J. (JSC-EG111)[Jacobs Technology, Inc.] via lustre-discuss" <lustre-discuss@lists.lustre.org> Reply-To: "Vicker, Darby J. (JSC-EG111)[Jacobs Technology, Inc.]" <darby.vicke...@nasa.gov> Date: Friday, September 22, 2023 at 2:49 PM To: Andreas Dilger <adil...@whamcloud.com> Cc: "lustre-discuss@lists.lustre.org" <lustre-discuss@lists.lustre.org> Subject: [BULK] Re: [lustre-discuss] [EXTERNAL] Re: Data recovery with lost MDT data I’m only showing you the last 10 directories below but there are about 30 or 40 directories with a pretty uniform distribution between 6/20 and now. If it was a situation where we had been rolled back to 6/20 but directories were starting to be updated again, there should be a big gap with no updates. The rollback (when we deleted the “snapshot”) happened on Monday, 9/18. We could do another snapshot of the MDT, mount it read only and poke around in there if you think that would help. Actually, our backup process (which is running normally again) is doing just that. It takes quite a long time to complete so there is opportunity for me to investigate. From: Andreas Dilger <adil...@whamcloud.com> Date: Friday, September 22, 2023 at 1:36 AM To: "Vicker, Darby J. (JSC-EG111)[Jacobs Technology, Inc.]" <darby.vicke...@nasa.gov> Cc: "lustre-discuss@lists.lustre.org" <lustre-discuss@lists.lustre.org> Subject: Re: [EXTERNAL] Re: [lustre-discuss] Data recovery with lost MDT data CAUTION: This email originated from outside of NASA. Please take care when clicking links or opening attachments. Use the "Report Message" button to report suspicious messages to the NASA SOC. On Sep 21, 2023, at 16:06, Vicker, Darby J. (JSC-EG111)[Jacobs Technology, Inc.] <darby.vicke...@nasa.gov<mailto:darby.vicke...@nasa.gov>> wrote: I knew an lfsck would identify the orphaned objects. That’s great that it will move those objects to an area we can triage. With ownership still intact (and I assume time stamps too), I think this will be helpful for at least some of the users to recover some of their data. Thanks Andreas. I do have another question. Even with the MDT loss, the top level user directories on the file system are still showing current modification times. I was a little surprised to see this – my expectation was that the most current time would be from the snapshot that we accidentally reverted to, 6/20/2023 in this case. Does this make sense? The timestamps of the directories are only stored on the MDT (unlike regular files which keep of the timestamp on both the MDT and OST). Is it possible that users (or possibly recovered clients with existing mountpoints) have started to access the filesystem in the past few days since it was recovered, or an admin was doing something that would have caused the directories to be modified? Is it possible you have a newer copy of the MDT than you thought? [dvicker@dvicker ~]$ ls -lrt /ephemeral/ | tail 4 drwx------ 2 abjuarez abjuarez 4096 Sep 12 13:24 abjuarez/ 4 drwxr-x--- 2 ksmith29 ksmith29 4096 Sep 13 15:37 ksmith29/ 4 drwxr-xr-x 55 bjjohn10 bjjohn10 4096 Sep 13 16:36 bjjohn10/ 4 drwxrwx--- 3 cbrownsc ccp_fast 4096 Sep 14 12:27 cbrownsc/ 4 drwx------ 3 fgholiza fgholiza 4096 Sep 18 06:41 fgholiza/ 4 drwx------ 5 mtfoste2 mtfoste2 4096 Sep 19 11:35 mtfoste2/ 4 drwx------ 4 abenini abenini 4096 Sep 19 15:33 abenini/ 4 drwx------ 9 pdetremp pdetremp 4096 Sep 19 16:49 pdetremp/ [dvicker@dvicker ~]$ From: Andreas Dilger <adil...@whamcloud.com<mailto:adil...@whamcloud.com>> Date: Thursday, September 21, 2023 at 2:33 PM To: "Vicker, Darby J. (JSC-EG111)[Jacobs Technology, Inc.]" <darby.vicke...@nasa.gov<mailto:darby.vicke...@nasa.gov>> Cc: "lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org>" <lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org>> Subject: [EXTERNAL] Re: [lustre-discuss] Data recovery with lost MDT data CAUTION: This email originated from outside of NASA. Please take care when clicking links or opening attachments. Use the "Report Message" button to report suspicious messages to the NASA SOC. In the absence of backups, you could try LFSCK to link all of the orphan OST objects into .lustre/lost+found (see lctl-lfsck_start.8 man page for details). The data is still in the objects, and they should have UID/GID/PRJID assigned (if used) but they have no filenames. It would be up to you to make e.g. per-user lost+found directories in their home directories and move the files where they could access them and see if they want to keep or delete the files. How easy/hard this is to do depends on whether the files have any content that can help identify them. There was a Lustre hackathon project to save the Lustre JobID in a "user.job" xattr on every object, exactly to help identify the provenance of files after the fact (regardless of whether there is corruption), but it only just landed to master and will be in 2.16. That is cold comfort, but would help in the future. Cheers, Andreas On Sep 20, 2023, at 15:34, Vicker, Darby J. (JSC-EG111)[Jacobs Technology, Inc.] via lustre-discuss <lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org>> wrote: Hello, We have recently accidentally deleted some of our MDT data. I think its gone for good but looking for advice to see if there is any way to recover. Thoughts appreciated. We run two LFS’s on the same set of hardware. We didn’t set out to do this, but it kind of evolved. The original setup was only a single filesystem and was all ZFS – MDT and OST’s. Eventually, we had some small file workflows that we wanted to get better performance on. To address this, we stood up another filesystem on the same hardware and used a an ldiskfs MDT. However, since were already using ZFS, under the hood the storage device we build the ldisk MDT on comes from ZFS. That gets presented to the OS as /dev/zd0. We do a nightly backup of the MDT by cloning the ZFS dataset (this creates /dev/zd16, for whatever reason), snapshot the clone, mount that as ldiskfs, tar up the data and then destroy the snapshot and clone. Well, occasionally this process gets interrupted, leaving the ZFS snapshot and clone hanging around. This is where things go south. Something happens that swaps the clone with the primary dataset. ZFS says you’re working with the primary but its really the clone, and via versa. This happened about a year ago and we caught it, were able to “zfs promote” to swap them back and move on. More details on the ZFS and this mailing list here. https://zfsonlinux.topicbox.com/groups/zfs-discuss/Tcb8a3ef663db0031-M5a79e71768b20b2389efc4a4 http://lists.lustre.org/pipermail/lustre-discuss-lustre.org/2022-June/018154.html It happened again earlier this week but we didn’t remember to check this and, in an effort to get the backups going again, destroyed what we thought were the snapshot and clone. In reality, we destroyed the primary dataset. Even more unfortunately, the stale “snapshot” was about 3 months old. This stale snapshot was also preventing our MDT backups from running so we don’t have those to restore from either. (I know, we need better monitoring and alerting on this, we learned that lesson the hard way. We had it in place after the June 2022 incident, it just wasn’t working properly.) So at the end of the day, the data lives on the OST’s we just can’t access it due to the lost metadata. Is there any chance at data recovery. I don’t think so but want to explore any options. Darby _______________________________________________ lustre-discuss mailing list lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org Cheers, Andreas -- Andreas Dilger Lustre Principal Architect Whamcloud
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