[LU-17164] Old files not accessible anymore with lma incompat=2 and no lov

Thu, 5 Oct 2023 00:47:34 +0000

Hello!
On our Oak filesystem, today running 2.12.8+patches (very close to 2.12.9), a few old files, which were last modified in March 2020, cannot be accessed anymore. From a client:

[root@oak-cli01 ~]# ls -l /oak/stanford/groups/khavari/users/dfporter/before_2021_projects/genome/fastRepEnrich_hg38/fastRepEnrich/fastRE_Setup
ls: cannot access '/oak/stanford/groups/khavari/users/dfporter/before_2021_projects/genome/fastRepEnrich_hg38/fastRepEnrich/fastRE_Setup/pseudogenome.fasta': No such file or directory
ls: cannot access '/oak/stanford/groups/khavari/users/dfporter/before_2021_projects/genome/fastRepEnrich_hg38/fastRepEnrich/fastRE_Setup/repnames.bed': No such file or directory
total 0
-????????? ? ? ? ?            ? pseudogenome.fasta
-????????? ? ? ? ?            ? repnames.bed

We found them with no trusted.lov, just a trusted.lma and ACLs (system.posix_acl_access), owned by root / root and 0000 as permissions (note that I since changed the ownership/permissions which are reflected in the debugfs output below, so the ctime has been updated too):

oak-MDT0000> debugfs:  stat ROOT/stanford/groups/khavari/users/dfporter/before_2021_projects/genome/fastRepEnrich_hg38/fastRepEnrich/fastRE_Setup/pseudogenome.fasta
Inode: 745295211   Type: regular    Mode:  0440   Flags: 0x0
Generation: 392585436    Version: 0x00000000:00000000
User:     0   Group:     0   Project:     0   Size: 0
File ACL: 0
Links: 1   Blockcount: 0
Fragment:  Address: 0    Number: 0    Size: 0
 ctime: 0x651b1517:a256cacc -- Mon Oct  2 12:08:07 2023
 atime: 0x649be9dc:d980bf08 -- Wed Jun 28 01:05:48 2023
 mtime: 0x5e7ae8a2:437ca450 -- Tue Mar 24 22:14:10 2020
crtime: 0x649be9dc:d980bf08 -- Wed Jun 28 01:05:48 2023
Size of extra inode fields: 32
Extended attributes:
  lma: fid=[0x2f800028cf:0x944c:0x0] compat=0 incompat=2
  system.posix_acl_access:
    user::r--
    group::rwx
    group:3352:rwx
    mask::r--
    other::---
BLOCKS:

oak-MDT0000> debugfs:  stat ROOT/stanford/groups/khavari/users/dfporter/before_2021_projects/genome/fastRepEnrich_hg38/fastRepEnrich/fastRE_Setup/repnames.bed
Inode: 745295212   Type: regular    Mode:  0440   Flags: 0x0
Generation: 392585437    Version: 0x00000000:00000000
User:     0   Group:     0   Project:     0   Size: 0
File ACL: 0
Links: 1   Blockcount: 0
Fragment:  Address: 0    Number: 0    Size: 0
 ctime: 0x651b1517:a256cacc -- Mon Oct  2 12:08:07 2023
 atime: 0x649be9dc:d980bf08 -- Wed Jun 28 01:05:48 2023
 mtime: 0x5e7ae8ad:07654c1c -- Tue Mar 24 22:14:21 2020
crtime: 0x649be9dc:d980bf08 -- Wed Jun 28 01:05:48 2023
Size of extra inode fields: 32
Extended attributes:
  lma: fid=[0x2f800028cf:0x953d:0x0] compat=0 incompat=2
  system.posix_acl_access:
    user::r--
    group::rwx
    group:3352:rwx
    mask::r--
    other::---
BLOCKS:

Note also that the crtime is recent because we migrated this MDT (MDT0000) using a backup/restore method to new hardware last June 2023, but we have verified yesterday that these files were already like that before the MDT migration (we still have access to the old storage array). So we know it's not something we introduced during the migration. Just in case you notice the crtime and ask

Timeline as we understand it:

March 2020 these files likely created, or at least last modified, this was on Lustre 2.10.8
October 2020: we upgraded from 2.10.8 to 2.12.5
June 2022: we have recorded a SATTR changelog event with those FIDs but on oak-MDT0002, I don't know why as they are stored on MDT0.
June 2023: we perform a MDT backup/restore to new hardware but we confirmed this didn't introduce the problem
October 2023: our users notice and report the problem.

Changelog events on those FIDs (we log them to Splunk):

2022-06-08T13:15:14.793547861-0700 mdt=oak-MDT0002 id=9054081490 type=SATTR flags=0x44 uid=0 gid=0 target=[0x2f800028cf:0x944c:0x0]
2022-06-08T13:15:14.795309940-0700 mdt=oak-MDT0002 id=9054081491 type=SATTR flags=0x44 uid=0 gid=0 target=[0x2f800028cf:0x953d:0x0]

It's really curious to see those coming from oak-MDT0002 !??
We have also noticed these errors in the logs:

Oct 02 11:35:12 oak-md1-s1 kernel: LustreError: 59611:0:(mdt_open.c:1227:mdt_cross_open()) oak-MDT0002: [0x2f800028cf:0x944c:0x0] doesn't exist!: rc = -14
Oct 02 11:35:37 oak-md1-s1 kernel: LustreError: 59615:0:(mdt_open.c:1227:mdt_cross_open()) oak-MDT0002: [0x2f800028cf:0x944c:0x0] doesn't exist!: rc = -14

Could Lustre be confused on which MDT these FIDs are supposed to be served because of corrupted metadata? Why on earth could oak-MDT0002 be involved here?

Parent FID:

[root@oak-cli01 ~]# lfs path2fid /oak/stanford/groups/khavari/users/dfporter/before_2021_projects/genome/fastRepEnrich_hg38/fastRepEnrich/fastRE_Setup
[0x200033e88:0x114:0x0]
[root@oak-cli01 ~]# lfs getdirstripe /oak/stanford/groups/khavari/users/dfporter/before_2021_projects/genome/fastRepEnrich_hg38/fastRepEnrich/fastRE_Setup
lmv_stripe_count: 0 lmv_stripe_offset: 0 lmv_hash_type: none

We tried to run lfsck namespace but it crashed our MDS likely due to ~~LU-14105~~ which is only fixed in 2.14:

      KERNEL: /usr/lib/debug/lib/modules/3.10.0-1160.83.1.el7_lustre.pl1.x86_64/vmlinux
    DUMPFILE: vmcore  [PARTIAL DUMP]
        CPUS: 64
        DATE: Mon Oct  2 22:55:53 2023
      UPTIME: 48 days, 16:17:05
LOAD AVERAGE: 2.94, 3.39, 3.52
       TASKS: 3287
    NODENAME: oak-md1-s2
     RELEASE: 3.10.0-1160.83.1.el7_lustre.pl1.x86_64
     VERSION: #1 SMP Sun Feb 19 18:38:37 PST 2023
     MACHINE: x86_64  (3493 Mhz)
      MEMORY: 255.6 GB
       PANIC: "Kernel panic - not syncing: LBUG"
         PID: 24913
     COMMAND: "lfsck_namespace"
        TASK: ffff8e62979fa100  [THREAD_INFO: ffff8e5f41a48000]
         CPU: 8
       STATE: TASK_RUNNING (PANIC)

crash> bt
PID: 24913  TASK: ffff8e62979fa100  CPU: 8   COMMAND: "lfsck_namespace"
 #0 [ffff8e5f41a4baa8] machine_kexec at ffffffffaac69514
 #1 [ffff8e5f41a4bb08] __crash_kexec at ffffffffaad29d72
 #2 [ffff8e5f41a4bbd8] panic at ffffffffab3ab713
 #3 [ffff8e5f41a4bc58] lbug_with_loc at ffffffffc06538eb [libcfs]
 #4 [ffff8e5f41a4bc78] lfsck_namespace_assistant_handler_p1 at ffffffffc1793e68 [lfsck]
 #5 [ffff8e5f41a4bd80] lfsck_assistant_engine at ffffffffc177604e [lfsck]
 #6 [ffff8e5f41a4bec8] kthread at ffffffffaaccb511
 #7 [ffff8e5f41a4bf50] ret_from_fork_nospec_begin at ffffffffab3c51dd

According to Robinhood, these files' striping is likely 1 so we're going to try to find their object IDs.

Do you have any idea on how to resolve this without running lfsck? How can we find/reattach the objects?

Thanks!

Whamcloud Community JIRA

[LU-17164] Old files not accessible anymore with lma incompat=2 and no lov