[LU-16208] ldiskfs mdt backup seek error

• Status: Open
• Project: Lustre
• Type: Question/Request
• Priority: Minor
• Reporter: Mahmoud Hanafi
• Assignee: Peter Jones
• Resolution: Unresolved

Description

Mounting mdt as ldiskfs and running a file level backup we got the following error. What is this error?

The tar command was

tar czf /backups/mdt.tgz --xattrs --xattrs-include=trusted.* --sparse .

nbpxx-srv7: tar: ./REMOTE_PARENT_DIR/0x340005a45\:0x1e4\:0x0/XXX/PATH_HIDDED/file1: Cannot seek to 5486809098596: Invalid argument
nbpxx-srv7: tar: ./REMOTE_PARENT_DIR/0x340005a45\:0x1e4\:0x0/XXX/PATH_HIDDED/file2: Cannot seek to 5184429353460: Invalid argument
nbpxx-srv7: tar: ./REMOTE_PARENT_DIR/0x340005a45\:0x1e4\:0x0/XXX/PATH_HIDDED/file3: Cannot seek to 14633117681632: Invalid argument
nbpxx-srv7: tar: ./REMOTE_PARENT_DIR/0x340005a45\:0x1e4\:0x0/XXX/PATH_HIDDED/file4: Cannot seek to 5184429171768: Invalid argument
nbpxx-srv7: tar: Exiting with failure status due to previous errors 

Comments

[Andreas Dilger]

Mahmoud, what version of Lustre is this?  MDS files shouldn't have data in them, so it isn't clear what tar is doing here.

Also, have you run e2fsck on this MDT?  It may be that the filesystem has some corrupted inodes.

[Mahmoud Hanafi]

There shouldn't be any data. This 2.12.8. 

Here is the inode info

debugfs:  stat TTBW/simulations/FAC-4c-F0-LG-6deg/fwh_sld.snc
Inode: 114840990   Type: regular    Mode:  0770   Flags: 0x0
Generation: 1596952107    Version: 0x0000002b:00a38e8b
User: 846235202   Group: 21603   Project:     0   Size: 5486809098596
File ACL: 0
Links: 1   Blockcount: 0
Fragment:  Address: 0    Number: 0    Size: 0
 ctime: 0x633b097c:00000000 -- Mon Oct  3 09:10:36 2022
 atime: 0x632e67ef:00000000 -- Fri Sep 23 19:14:07 2022
 mtime: 0x631e6c19:00000000 -- Sun Sep 11 16:15:37 2022
crtime: 0x62f5a4ff:0f4ed044 -- Thu Aug 11 17:55:27 2022
Size of extra inode fields: 32
Extended attributes:
  lma: fid=[0x340029b94:0xb:0x0] compat=0 incompat=0
  linkea: idx=0 parent=[0x340028c72:0xad9:0x0] name='fwh_sld.snc'
  trusted.som (24) = 04 00 00 00 00 00 00 00 64 a9 4e 7f fd 04 00 00 b0 9d 7f fd 04 00 00 00
  trusted.lov (512)
BLOCKS:debugfs:  stat TTBW/simulations/FAC-3c-F0-nLG-6deg/fwh_sld.snc
Inode: 114848112   Type: regular    Mode:  0660   Flags: 0x0
Generation: 1594491852    Version: 0x00000024:085c82ce
User: 846235202   Group: 21603   Project:     0   Size: 5184429353460
File ACL: 0
Links: 1   Blockcount: 0
Fragment:  Address: 0    Number: 0    Size: 0
 ctime: 0x62df3c06:00000000 -- Mon Jul 25 17:57:42 2022
 atime: 0x630988eb:00000000 -- Fri Aug 26 20:00:59 2022
 mtime: 0x62df3c06:00000000 -- Mon Jul 25 17:57:42 2022
crtime: 0x62db8ece:a9577c50 -- Fri Jul 22 23:01:50 2022
Size of extra inode fields: 32
Extended attributes:
  lma: fid=[0x34002803d:0xb:0x0] compat=0 incompat=0
  linkea: idx=0 parent=[0x340025ea6:0x1d1e5:0x0] name='fwh_sld.snc'
  trusted.som (24) = 04 00 00 00 00 00 00 00 f4 e9 11 18 b7 04 00 00 10 66 18 b7 04 00 00 00
  trusted.lov (512)
BLOCKS:debugfs:  stat TTBW/simulations/FAC-2c-F0-LG-6deg/fwh_sld.snc
Inode: 114832177   Type: regular    Mode:  0770   Flags: 0x0
Generation: 1592577854    Version: 0x00000024:0dea2979
User: 846235202   Group: 21603   Project:     0   Size: 14633117681632
File ACL: 0
Links: 1   Blockcount: 0
Fragment:  Address: 0    Number: 0    Size: 0
 ctime: 0x62f3c2c3:00000000 -- Wed Aug 10 07:37:55 2022
 atime: 0x630c4755:00000000 -- Sun Aug 28 21:57:57 2022
 mtime: 0x62b4d5d4:00000000 -- Thu Jun 23 14:06:28 2022
crtime: 0x62b07042:5f33351c -- Mon Jun 20 06:04:02 2022
Size of extra inode fields: 32
Extended attributes:
  lma: fid=[0x340024e77:0xb:0x0] compat=0 incompat=0
  linkea: idx=0 parent=[0x340024b91:0x6b0:0x0] name='fwh_sld.snc'
  trusted.som (24) = 04 00 00 00 00 00 00 00 e0 07 c8 09 4f 0d 00 00 00 64 0a 4f 0d 00 00 00
  trusted.lov (512)
BLOCKS:debugfs:  stat TTBW/simulations/FAC-2c-F0-nLG-6deg/fwh_sld.snc
Inode: 114838297   Type: regular    Mode:  0770   Flags: 0x0
Generation: 1593962529    Version: 0x00000024:07f81409
User: 846235202   Group: 21603   Project:     0   Size: 5184429171768
File ACL: 0
Links: 1   Blockcount: 0
Fragment:  Address: 0    Number: 0    Size: 0
 ctime: 0x62d7119c:00000000 -- Tue Jul 19 13:18:36 2022
 atime: 0x63052766:00000000 -- Tue Aug 23 12:15:50 2022
 mtime: 0x62d25f1c:00000000 -- Fri Jul 15 23:47:56 2022
crtime: 0x62d05b8b:1325e688 -- Thu Jul 14 11:08:11 2022
Size of extra inode fields: 32
Extended attributes:
  lma: fid=[0x340026d45:0x8:0x0] compat=0 incompat=0
  linkea: idx=0 parent=[0x340025ea6:0x1d0cb:0x0] name='fwh_sld.snc'
  trusted.som (24) = 04 00 00 00 00 00 00 00 38 24 0f 18 b7 04 00 00 50 4f 18 b7 04 00 00 00
  trusted.lov (512)
BLOCKS:debugfs: 

[Andreas Dilger]

Was this filesystem upgraded from a much older release? The size of files used to be stored in the MDS inode.i_size, but this caused problems for "tar" and similar, so we stopped doing it. However, the file creation time seems very recent so I'm not sure why that is the case. Do these sizes match the actual file size when viewed in the mounted Lustre filesystem?

Since the reported files have zero blocks allocated, it looks like they could be truncated to zero bytes to avoid having tar complain about them. The file size in the MDT is not used for anything today except for DoM files.