SUMMARY: Soft error rate during backup

From: Craig Barker (tybse2!cbarker@postman.eglin.af.mil)
Date: Mon May 06 1996 - 07:59:01 CDT


Well, we have a concensus on the summary, but first the original
question:

*****************************************************************
I have a SPARCstation 10 model 30 running Solaris 2.3.
I perform backups every night to an 8mm tape drive using
the ufsdump utility. I recently purchased SONY computer grade 8mm
112M data cartridges. About 1/2 of the tapes have errors of the
following nature after about 2 or 3 backup uses:

May 2 03:03:54 tybse2 unix: WARNING: /iommu@f,e0000000/sbus@f,e0001000/esp@1,200000/st@4,0 (st19):
May 2 03:03:54 tybse2 unix: Soft error rate (7%) during writing was too high
May 2 03:03:54 tybse2 unix: Please, replace tape cartridge

I have ensured that my tape drive is clean, etc. My question is this;
Is there some performance tuning that I can do to the OS or ufsdump utility
to make these tapes usable, or are the quality of SONY tapes really this
pathetic? I used to get at least 15 dumps on Verbatim tapes before SOME of
them began giving these errors. Guess I won't be buying any garbage from
SONY!
*****************************************************************

The majority of responses indicate the following:

(1) SONY TAPES ARE JUNK!!! Many people had good things to say about Exabyte
     tapes.

(2) Slowlaris has yet another bug. The tape driver incorrectly counts the
     soft error percentage. There is a patch for Solaris 2.4, but not for
     2.3. Sun's "response" was to add the following entry in the /etc/system
     file to suppress the soft error rate messages on the tape drive.
     
     * suppress soft error rate messages on tape drive
 
     set st:st_report_soft_errors_on_close=0

Hope this helps, and thanks to everyone who responded, - too many to list!
cbarker@cp.tybrin.com



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