Date: Sun, 13 Mar 2005 00:26:56 -0800 From: "Loren M. Lang" <lorenl@alzatex.com> To: Jerry McAllister <jerrymc@clunix.cl.msu.edu> Cc: freebsd-questions@freebsd.org Subject: Re: What's the easiest way to do a backup and verify? Message-ID: <20050313082656.GB18080@alzatex.com> In-Reply-To: <200503071447.j27ElWW10343@clunix.cl.msu.edu> References: <1946173739.20050307145644@wanadoo.fr> <200503071447.j27ElWW10343@clunix.cl.msu.edu>
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--vGgW1X5XWziG23Ko Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 07, 2005 at 09:47:31AM -0500, Jerry McAllister wrote: > >=20 > > Is there an easy way to combine a backup and verify when doing backups > > with dump? > >=20 > > On Windows NT it's just a matter of checking a box. I seem to recall > > the last time I looked into this on UNIX there was no easy way to > > accomplish a verify operation for a backup, but perhaps things have > > changed with FreeBSD 5.3 (?). > >=20 > > I've never had a problem with backup (I backup to DAT tape), but I'd > > feel better if every backup was followed by a verify to make sure the > > tape is readable. >=20 > Actually, if used frequently for backups - such as every day, DAT is > notoriously prone to failure. So, it is a good idea to check dumps > made to DAT. Unfortunately, there is not a reasonable way to=20 > automatically do it. There is a verify, but it cannot work on a > running system, because it compares files (inodes) on the tape back > to the ones on disk. Any changes mean an error, even if it was a > real change in the file between the time it was written and the > time it was read back. >=20 > The only real thing you can do is to read back the tape and look > for a couple of files with fairly high inode numbers for each file > system dumped. If you can read them, you can assume the tape > is readable. I'm not very familiar with tapes, but I think that the dump is written straight out to something like /dev/st0 right? So then wouldn't a second dump of the same snapshot diffed to the tape device be a good for a verify? Position tape at beginning of dump dump / | diff - /dev/st0 Though I don't have much experience with either dump or tapes to verify. >=20 > ////jerry >=20 > >=20 > > --=20 > > Anthony > >=20 > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.o= rg" --=20 I sense much NT in you. NT leads to Bluescreen. Bluescreen leads to downtime. Downtime leads to suffering. NT is the path to the darkside. Powerful Unix is. Public Key: ftp://ftp.tallye.com/pub/lorenl_pubkey.asc Fingerprint: CEE1 AAE2 F66C 59B5 34CA C415 6D35 E847 0118 A3D2 =20 --vGgW1X5XWziG23Ko Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFCM/lQbTXoRwEYo9IRAk8LAJ49uNlXlL2YIyqd/oz+o/H05ZrUBgCfbvg2 fdxJv70AddvJbExI8zqoh+4= =EeLW -----END PGP SIGNATURE----- --vGgW1X5XWziG23Ko--
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