Subject: Re: Amanda backups: gtar or dump?
To: None <firstname.lastname@example.org>
From: Greg A. Woods <email@example.com>
Date: 10/28/1998 19:46:21
[ On Wed, October 28, 1998 at 09:58:45 (-0500), Michael C. Richardson wrote: ]
> Subject: Re: Amanda backups: gtar or dump?
> I think this is a major feature, but it does render -t useful for
> *verifying* a backup. I've been bitten by this problem on numerous occasions.
> I need to add -T or -V to restore to make it note the highest numbered
> inode, and attempt to restore that file from tape to /dev/null in order to
> force the entire tape to be read. No, I won't do this all the time, but I
> sure *will* do this at least once a month, and anytime I mess with kernels,
> SCSI controllers, disks, tapes, or *termination*.
Well, if all you want to do is ensure the data can be read successfully
off the tape then dd is sufficient for testing, and can be faster. Most
(all?) linear recording devices that one might use for backups these
days will notice a corrupted "sector" and cause the device driver to
emit an error and fail the current read().
Trying to read the last file of a dump is not likely to verify the
consistency of the dump. Only a full restore would do that.
Greg A. Woods
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