On 8/22/11 11:22 AM, Horacio Sanson wrote:
I use amanda to backup my clients data with defaults tapecycle 10 and
dumpcycle 7 and cronjob running amdump every night.
Now I have a client that requires 15min recovery guarantee... that is
in event of disaster I must be able to recover all data to a stable
state loosing at most 15 minutes of data. For this I need amanda to
make backups every 15 minutes.
My guess from reading the documentation is that I need to set the
runspercycle to 675 (= 60min x 24 hours x 7 dumpcycle / 15 min
intervals) and run amdump in a cron every 15 min. Has someone done
something like this? Any tips/help would be greatly appreciated.
Now assuming my guess is correct how would amanda handle a full dump.
I understand amanda will perform a full backup at least once every
dumpcycle but my clients data is larger than 200GB and a full backup
can take a few hours. What happens if a new amdump run (15 min later)
starts before the full backup has finished? would this create
corrupted backups?
That's nuts.
What you need is RAID6 or ZFS Raidz2 or better and either LVM or ZFS snapshots
every 10 minutes or so.
I don't think you can design a backup system to solve a problem that needs to be solved at the level
of system design and redundancy. In other words, you need servers and storage with sufficient
redundancy that they won't be lost. Perhaps a cluster or mirrored systems with failover. Then you
need backups in case some data is lost or corrupted due to human error. If the building burns down,
then, in order to have a 15 minute guarantee, you have to have constant mirroring with an outside
redundant system.
I think if you tried to contract with IBM for backups with a 15 minute guarantee, they would charge
you an arm and a leg, or they would push back and make you accept something much less than a 15
minute guarantee. They would probably also throw a bunch of legal caveats into the contract. Sort of
like reading the insurance policy on your home and discovering the things you are not covered for
(various sorts of natural disasters and/or war, etc.)
--
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Chris Hoogendyk
-
O__ ---- Systems Administrator
c/ /'_ --- Biology& Geology Departments
(*) \(*) -- 140 Morrill Science Center
~~~~~~~~~~ - University of Massachusetts, Amherst
<[email protected]>
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Erdös 4
