There is a patch for this. It came out at the end of last week.
Save Sets Overwritten Due to Missing Volume Next field Update (LGTpa69733)
Under certain conditions NetWorker software fails to update the Next file
marker in the media database. The Next file marker is used to position a
tape for writing and is only used when an appendable volume is mounted for
writing or when a volume sits idle in a tape drive for 30 seconds or more.
All of the following conditions must be present for a completed save set to
be overwritten, making this a rare occurrence:
A backup operation is using a tape-type volume. Advanced file type device
backup operations will not experience any issue. Save set writing to tape
must span to another volume with the 'End note' being the only item written
to the next volume. No actual data is written to next volume. The triggering
save set must either be the only save set writing to the tape when the
volume became full or a multiplexed save set must have completed writing all
its data on the last record of tape at the same time when the volume became
full. The continuation volume (which did not have the Next field properly
updated) was remounted at some time for writing or had been sitting idle in
the tape drive for 30 seconds or more. If the continuation volume was used
to completion (marked full) or was never idle, then the volume would not be
remounted for writing and no save sets overwritten.
Only save sets on the continuation volume written after the End Note will
be overwritten if the volume is remounted for writing. No other volumes are
effected.
LEGATO has generated a fix for all operating system platforms for NetWorker
release 7.1.3 and 7.2.
LEGATO recommends that you obtain and apply the fix (nsrmmd is the only
NetWorker program included in the fix) on all NetWorker Servers and Storage
Nodes.
If you are running a NetWorker release prior to 7.1.3, upgrade to a later
release (7.1.3 or 7.2) and apply the fix. This fix is NetWorker release
specific.
The fix can be found at:
ftp://ftp.legato.com/pub/NetWorker/Updates/LGTpa69733/.
Download the appropriate version for your release and the README for
installation instructions.
If you have previously received a hotfix for the nsrmmd program, contact
Support to obtain a combined fix.
Note: Check the ftp site for future availability for a fix for NetWorker
release 6.1.4 and 7.1.2.
A tool (mdbck) has been developed to assist in identifying volumes that are
currently susceptible to being overwritten. This tool is available at the
same ftp location as the
fix: ftp://ftp.legato.com/pub/NetWorker/Updates/LGTpa69733/. Instructions
for using the mdbck are detailed in an accompanying readme.txt file. The
tool is available for installation on Solaris, HP-UX,Windows and Linux, but
can be run against any NetWorker Server regardless of operating system.
Important: This tool will not detect volumes that may have been overwritten
previously as a result of this issue.
Siobhán Ellis
Senior Technology Consultant
Enstor
Level 10, 118 Alfred St
Milsons Point
NSW 2061
Australia
Mobile: +61 424 750 544
Phone: +61 2 9900 2100
Fax: +61 2 9900 2199
e-mail: siobhan.ellis AT enstor.com DOT au
>>> tpbsys AT RIT DOT EDU 8/04/2005 11:17:48 am >>>
While reading the known limitations in the v7.1 and v7.2 release notes,
I found the following:
LGTpa69733 Save sets overwritten due to missing volume next field
The section goes on to explain circumstances where data is written to
tape in such a way that it can be overwritten by other data.
Has anyone seen this happen or have more information?
Thanks.
Teresa
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Siobhan Ellis.vcf
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