• Storage & Archiving

  Recover data from formatted LTFS tape

  Posted by Pavel Repy on February 15, 2019 at 8:17 am

  Hello.
  Faced the big problem. I thoughtlessly formatted LTFS media with -f parameter.
  Is there any possible ways to recover the data? As I know data partition isn’t wiped, but index partition ovewritten.

  Also I restored from server’s backup LTFS’ cached data files:

  RD0344L6.label.ansi.0
  RD0344L6.label.ansi.1
  VOL1RD0344L LTFS 4

  RD0344L6.label.ltfs.0
  RD0344L6.label.ltfs.1
  [?xml version="1.0" encoding="UTF-8"?]
[ltfslabel version="2.4.0"]
[creator]IBM LTFS 2.4.0.2 (10071) - Linux - ltfs.tape.library[/creator]
[formattime]2018-12-12T05:32:42.748924276Z[/formattime]
[volumeuuid]3bfc8ad1-f852-46e2-b097-1f74611087f1[/volumeuuid]
[location]
[partition]a[/partition]
[/location]
[partitions]
[index]a[/index]
[data]b[/data]
[/partitions]
[blocksize]524288[/blocksize]
[compression]true[/compression]
[/ltfslabel]


  RD0344L6.schema
  [?xml version="1.0" encoding="UTF-8"?]
[ltfsindex version="2.4.0"]
[creator]IBM LTFS 2.4.0.2 (10071) - Linux - ltfs.tape.library - Unmount - 0[/creator]
[volumeuuid]3bfc8ad1-f852-46e2-b097-1f74611087f1[/volumeuuid]
[generationnumber]44[/generationnumber]
[updatetime]2018-12-13T01:07:47.000284295Z[/updatetime]
[location]
[partition]a[/partition]
[startblock]5[/startblock]
[/location]
[previousgenerationlocation]
[partition]b[/partition]
[startblock]4582362[/startblock]
[/previousgenerationlocation]
[allowpolicyupdate]true[/allowpolicyupdate]
[highestfileuid]19[/highestfileuid]
[volumelockstate]unlocked[/volumelockstate]
[directory]
[name/]
[readonly]false[/readonly]
[creationtime]2018-12-12T05:32:42.748924276Z[/creationtime]
[changetime]2018-12-13T01:07:09.712685534Z[/changetime]
[modifytime]2018-12-13T01:07:09.712685534Z[/modifytime]
[accesstime]2018-12-12T05:32:42.748924276Z[/accesstime]
[backuptime]2018-12-12T05:32:42.748924276Z[/backuptime]
[fileuid]1[/fileuid]
[contents]
[file]
[name]d6fee0d6622b0dc086581ae1062b71ee_RuqhUjIGbb.lm1[/name]
[length]1412240166640[/length]
[readonly]false[/readonly]
[creationtime]2018-12-12T18:40:44.520017392Z[/creationtime]
[changetime]2018-12-12T20:27:18.960864690Z[/changetime]
[modifytime]2018-12-12T20:27:18.960864690Z[/modifytime]
[accesstime]2018-12-12T22:18:51.955513326Z[/accesstime]
[backuptime]2018-12-12T18:40:44.520017392Z[/backuptime]
[fileuid]2[/fileuid]
[extentinfo]
[extent]
[fileoffset]0[/fileoffset]
[partition]b[/partition]
...


  RD0344L6.mamdata
  that’s binary

  I guess that’s what I need is write this data to the tape restoring lost index partition. But how should I do?
  I tried rude:
  
dd if=RD0344L6.label.ansi.0 of=/dev/nst0 bs=524288
dd if=RD0344L6.label.ltfs.0 of=/dev/nst0 bs=524288
mt -f /dev/nst0 weof
dd if=RD0344L6.schema of=/dev/nst0 bs=524288
mt -f /dev/nst0 weof


  and it had written correctly. But when I call ltfsck it fails:

  
LTFS17160I Maximum device block size is 524288
LTFS16014I Checking LTFS file system on '/dev/nst0'
LTFS11183E Comparing labels: volume UUID mismatch
LTFS11172E Cannot verify labels: comparison failed (-1013)
LTFS11009E Cannot read volume: failed to read partition labels.
LTFS16080E Cannot check volume (8)
LTFS20076I Triggering drive diagnostic dump
LTFS20096I Diagnostic dump complete


  Have you please any advices what should I do?
  I use enterprise IBM LTFS version 2.4.0.2. and Single-Drive Edition for standalone drive.

  Pavel Repy replied 7 years, 6 months ago 1 Member · 0 Replies
• 0 Replies

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