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Conference decwet::networker

Title:NetWorker
Notice:kits - 12-14, problem reporting - 41.*, basics 1-100
Moderator:DECWET::RANDALL.com::lenox
Created:Thu Oct 10 1996
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:750
Total number of notes:3361

347.0. "'bad last fragment' on recover" by ESSB::TMOORE () Fri Jan 24 1997 01:16

Hello,
	I'm running NetWorker V4.2A on Digital Unix 3.2C, on both server 
client systems. I'm trying to restore a file from tape, that was backed
up a couple of months earlier. Due to index size, the file is no longer
in file index. I used the scanner command to rebuild the index without
any problem. When I select the file, either with nwrecover or recover I
get 'bad last fragment' error from the server, and the file is not restored.
I get this error from three different savesets (different tapes). Other
files can be restored from these tapes. Could the original file have been
corrupt?. Has anyone seen the error? I've searched the docs and this 
notesfile. Any suggestions appreciated.
Thanks,
Tom. 
T.RTitleUserPersonal
Name
DateLines
347.1please post exact text of error messageDECWET::EVANSBe a Point Of Light!Fri Jan 24 1997 10:473
that will help us research what might be happening

thanks
347.2error messageESSB::TMOOREThu Feb 06 1997 04:0850
Sorry for the delay, I've been out of the plant.
The file I need to restore is /var/spool/cron/crontabs/root.
Using the nwrecover interface I select the file and appropriate
browsetime. I hit start and the following message comes up
immediately:

  Recovering 1 file from /usr/var/spool/cron/crontabs/ into /usr/var/spool/cron
  Total estimated disk space needed for recover is 3 KB.

  Volumes needed (all on-line):
          ilosrv.0049 at /dev/nrmt0h
  Requesting 1 file, this may take a while...
  Recover failed from NSR server `ilosrv.ilo.dec.com': bad last fragment
  Didn't recover requested file ./root
  Received 0 files from NSR server `ilosrv.ilo.dec.com'
  Recover completion time: Thu Feb 06 11:51:06 1997

Using the nwrecover interface I select the parent directory (crontabs),
use relocate (temp) and appropriate browsetime. Hit start and the following comes up
after a few minutes.

  Recovering 17 files within /usr/var/spool/cron/ into /usr/var/spool/cron/temp
  Total estimated disk space needed for recover is 32 KB.

  Volumes needed (all on-line):
          ilosrv.0049 at /dev/nrmt0h
  Requesting 17 files, this may take a while...
  [uasm: -r ./crontabs/.new..adm]
  compressasm -r ./crontabs/.new..adm
  [uasm: -r ./crontabs/.new..root]
  [uasm: -r ./crontabs/.new..sys]
  compressasm -r ./crontabs/.new..root
  compressasm -r ./crontabs/.new..sys
  [uasm: -r ./crontabs/cronuucp]
  [uasm: -r ./crontabs/uucp]
  [uasm: -r ./crontabs/.proto..adm]
  compressasm -r ./crontabs/cronuucp
  compressasm -r ./crontabs/uucp
  [uasm: -r ./crontabs/.proto..root]
  [uasm: -r ./crontabs/.proto..sys]
  compressasm -r ./crontabs/.proto..adm  
  compressasm -r ./crontabs/.proto..root
  compressasm -r ./crontabs/.proto..sys
  nwrecover: unknown error running compressasm on file ./crontabs/.proto..sys
  nwrecover: recover failed: Error receiving files from NSR server `ilosrv.ilo.dec
  .com'

  Recover completion time: Thu Feb 06 11:50:11 1997

The files listed above are restored, but with zero byte size.
347.3tried this on V4.2B server/clientDECWET::EVANSBe a Point Of Light!Thu Feb 06 1997 11:1026
Couldn't get it to fail... tried

root@mrcofe> echo "compressasm: * ?.*" > /usr/var/spool/cron/.nsr
root@mrcofe> save -smrcofe -bDefault -v /usr/var/spool/cron/

which saved using compression OK.

then

root@mrcofe> recover -smrcofe -v /var/spool/cron
recover: Current working directory is /var/spool/cron/
recover> add *
/var/spool/cron/crontabs
14 file(s) marked for recovery
recover> vol
Volumes needed (all on-line):
        mrcofe.01 at /dev/nrmt0h
recover> reloc /tmp
recover> recover

--- but that didn't recover using compression

so tried GUI (nwrecover), and that also wroked but did not indicate compression
and now I've run out of time to experiment....

Out of curiousity, can you try this without compression?? and does it work OK?
347.4researched the codeDECWET::EVANSBe a Point Of Light!Fri Feb 07 1997 14:3216
I looked up bad last frag in the code tree, and found it in the recover
 (mm_recov.c) section (no suprises there), and tried to understand
 what was happening to get to this error message.

There is a loop processing "fragments", and if the fragment has too few or too
 many bytes, it is tossed, but those that are "just right" are setup with
 a volume. When the loop ends a check is made to see if the start frag
 is as expected, or the end frag is as expected...if not, an error message
 is displayed (bad last fragment).

My take on this means there is bad data coming in from tape, and causing
 this. What version of NetWorker did you use to save this data?
 Can you see this using NetWorker V4.2a (that is, save and then restore
 using NSR 4.2A)?

Thanks for your help on this.