W dniu 17.09.2024 o 18:04, Steve Estle pisze:
A healthy tape would be defiined as a tape where you can successfully read the
tape label and all written blocks on the tape volser without error (I/O error,
equipment check, etc).
Well, it is not so simple.
1. Media. Healthy tape media is no longer important for majority of
installations, because nowadays we have VTS (any vendor) and last
physical tape (TS1140) is really old, no longer supported, etc. However
yes, healthy physical tape media means the tape can be read. From
beginning to end of volume.
2. Healthy tape format. Yes, tapes have format. Labels, etc. Healthy
tape means existing labels and consistence between labels and between
labels and datasets (i.e. number of blocks).
3. Healthy virtual tape "media". Actually the tape volume is a file. The
file is usually OK, however one can imagine broken format, i.e.
accidentally overwritten fileds or other logical errors. Very unlikely
IMHO, however some malware on VTS or just errors in microcode could do
this.
4. Healthy physical media in VTS. Usually a VTS cache is RAID-protected
disk array, so the problems seems to be unlikely. Of course some VTSes
can offload virtual tape volumes on real tape - in that case the tape
can be duplicated or not. However such error could mean lost of volume
at all.
My €0.02
--
Radoslaw Skorupka
Lodz, Poland
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