On Mon, May 19, 2003 at 05:10:50PM +0930, Richard Russell wrote:
>
>
> Thing is, my users have this annoying habit of wanting something
> restored from three weeks ago... Which complicates issues further, as I
> need to have onsite backups for about a month, but would like to have
> offsites less than a week old...
Couple of random thoughts to consider.
Any sequence of tapes constituting one dumpcycle number of tapes is
effectively a "dumpset" (my term) current as of the last tape in the
set. If you backup daily (using 1 tape) and have 28 tapes in rotation,
then tapes 1-7, 8-14, ... are each a dumpset. They are "current" up to
the data of the dump on tape 7, 14,... In your Lego-infected mind :))
they are week 1, week 2, ... But at the same time, tapes 2-8, 9-15, and
3-9, 4-10, ... are also dumpsets. But they are current to different dates.
For a while I played like I was a real DP site (actually a SOHO). I used
my neighbors house for my secure offsite storage. My tapes are in magazines,
one dumpset per magazine, and I have 4 in rotation. The one in the changer
was "active". The offsite one was not the preceeding one, but the 2nd
preceeding one. I figured if I needed a file, most likely it would be
a recent one so I kept the most recent active one onsite. I.e., if Mag3
was in the changer, Mag1 was offsite, Mag2 was onsite for recovery of
recent files, and Mag4 was onsite, ready for the next switch of magazines.
Mag4 also could be used for recovery of 3-4 week old file deletion. My
offsite archive was a little older than some might like, i.e. 8-14 days
rather than 1-7 days.
With a second drive and the RAIT feature, you could duplicate your data,
one of offsite.
With some big cheap disks you could use the file: driver for onsite storage
of your months worth of daily backups and reserve the taped versions for
archival offsite. Make recoveries quite fast too.
--
Jon H. LaBadie jon AT jgcomp DOT com
JG Computing
4455 Province Line Road (609) 252-0159
Princeton, NJ 08540-4322 (609) 683-7220 (fax)
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