Veritas-bu

[Veritas-bu] disabling media positioning check

2004-04-15 18:30:38
Subject: [Veritas-bu] disabling media positioning check
From: tech2187 AT yahoo DOT com (K Chapman)
Date: Thu, 15 Apr 2004 15:30:38 -0700 (PDT)
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i disagree that it shouldnt be used, it is a case by case deal.  we had 
numerous position check errors and the suggested workaround was to touch this 
file.  after doing so, we have had media issues, but that was either legit bad 
tape drives or bad media. 
 
in our case, the media position errors were not a result of media/drive issues. 
 i compared the nb error time with syslog and bptm logs and saw no errors from 
the st driver  or read/write errors as we do if we get a valid media or drive 
error.  we didint start getting the errors until after a patch to 3.4.1, which 
introduced the check.  since we have turned off the check, we have had no 
issues with restores or backups and its been almost two years (did this in ver 
3.4 and now on 4.5)
 
weve been able to get away with the position check turned off because our tape 
tech is really crummy (mammoth2), but its what we had to do or we wouldnt be 
able to backup anything without trying 4 or five times

Rob Worman <rob AT worman DOT org> wrote:
This touchfile should be used with great caution, AND PROBABLY 
SHOULDN'T BE USED AT ALL. The NetBackup position checking logic is 
there for a very important reason, to help IMMEDIATELY detect an 
improper tape device setup that could result in data loss. 
(specifically the scenario where improper SCSI reserve/release 
configuration on a tape SAN results in one host rewinding a tape 
drive that another host is simultaneously writing to)

Thomas, I would claim that your status 86 problems are probably 
hardware-related, and this touchfile won't actually make any 
difference at all. (any device-level errors that accompany these 
NetBackup errors?) In any case, I'd suggest you open a Veritas 
support case before you put this touchfile in place.

HTH
rob


At 12:10 PM -0700 4/15/04, K Chapman wrote:
in /opt/openv/netbackup/db/config touch a file called NO_POSITION_CHECK

Thomas Tschida wrote:

Hello all,

I have a handful of policies defined for clustered file systems that
are consistenetly failing when attempting full backups. They are
erroring with status 86. I've tried forcing them to use diferent
drives, tapes, etc.

A third-party vendor we deal with thought there was a way to disable
the media positioning check by touching a file under openv/netbackup
similar to DISABLE_MEDIA_CHECK...but he wasn't sure of the exact
syntax.

Is anyone out there familiar with this file?

Thanks,

Tom Tschida
United Defense
_______________________________________________
Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu



aaarrrggghhh!!!!
FreeBSD rocks



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aaarrrggghhh!!!!
FreeBSD rocks
                
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<DIV>i disagree that it shouldnt be used, it is a case by case deal.&nbsp; we 
had numerous position check errors and the suggested workaround was to touch 
this file.&nbsp; after doing so, we have had media issues, but that was either 
legit bad tape drives&nbsp;or bad media.&nbsp;</DIV>
<DIV>&nbsp;</DIV>
<DIV>in our case, the media position errors were not a result of media/drive 
issues.&nbsp; i compared the nb error time with syslog and bptm logs and saw no 
errors from the st driver&nbsp; or read/write errors as we do if we get a valid 
media or drive error.&nbsp; we didint start getting the errors until after a 
patch to 3.4.1, which introduced the check.&nbsp; since we have turned off the 
check, we have had no issues with restores or backups and its been almost two 
years (did this in ver 3.4 and now on 4.5)</DIV>
<DIV>&nbsp;</DIV>
<DIV>weve been able to get away with the position check turned off because our 
tape tech is really crummy (mammoth2), but its what we had to do or we wouldnt 
be able to backup anything without trying 4 or five times<BR><BR><B><I>Rob 
Worman &lt;rob AT worman DOT org&gt;</I></B> wrote:</DIV>
<BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; 
BORDER-LEFT: #1010ff 2px solid">This touchfile should be used with great 
caution, AND PROBABLY <BR>SHOULDN'T BE USED AT ALL. The NetBackup position 
checking logic is <BR>there for a very important reason, to help IMMEDIATELY 
detect an <BR>improper tape device setup that could result in data loss. 
<BR>(specifically the scenario where improper SCSI reserve/release 
<BR>configuration on a tape SAN results in one host rewinding a tape <BR>drive 
that another host is simultaneously writing to)<BR><BR>Thomas, I would claim 
that your status 86 problems are probably <BR>hardware-related, and this 
touchfile won't actually make any <BR>difference at all. (any device-level 
errors that accompany these <BR>NetBackup errors?) In any case, I'd suggest you 
open a Veritas <BR>support case before you put this touchfile in 
place.<BR><BR>HTH<BR>rob<BR><BR><BR>At 12:10 PM -0700 4/15/04, K Chapman 
wrote:<BR>in
 /opt/openv/netbackup/db/config touch a file called 
NO_POSITION_CHECK<BR><BR>Thomas Tschida <THOMAS.TSCHIDA AT UDLP DOT 
COM>wrote:<BR><BR>Hello all,<BR><BR>I have a handful of policies defined for 
clustered file systems that<BR>are consistenetly failing when attempting full 
backups. They are<BR>erroring with status 86. I've tried forcing them to use 
diferent<BR>drives, tapes, etc.<BR><BR>A third-party vendor we deal with 
thought there was a way to disable<BR>the media positioning check by touching a 
file under openv/netbackup<BR>similar to DISABLE_MEDIA_CHECK...but he wasn't 
sure of the exact<BR>syntax.<BR><BR>Is anyone out there familiar with this 
file?<BR><BR>Thanks,<BR><BR>Tom Tschida<BR>United 
Defense<BR>_______________________________________________<BR>Veritas-bu 
maillist - Veritas-bu AT mailman.eng.auburn DOT 
edu<BR>http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu<BR><BR><BR><BR>aaarrrggghhh!!!!<BR>FreeBSD
 rocks<BR><BR><BR><BR>Do you Yahoo!?<BR>Yahoo! Tax Center - <HTTP:
 filing.html taxes.yahoo.com>File online <BR>by April 
15th<BR></BLOCKQUOTE><BR><BR>aaarrrggghhh!!!!<br>FreeBSD rocks<p>
                <hr size=1><font face=arial size=-1>Do you Yahoo!?<br>
Yahoo! Tax Center - <a href="http://taxes.yahoo.com/filing.html";>File online by 
April 15th</a>
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