On 8/22/11 11:17 AM, Matt Ingram wrote:
Hi All.
We're looking at using amanda for a virtual tape library.
We have two sites, and four SANs. here's a basic outline:
Site A
=====
ProductionA SAN (5TB)
"Backup of ProductionB" SAN (27TB)
Site B
=====
ProductionB SAN (10TB)
"Backup of ProductionA" SAN (17TB)
As per the above, we want to backup our data offsite. Looking for some thoughts on how we should
implement this. Some best practices, some gotchas, etc would be great.
Some initial questions are, where should we place our amanda backup servers. We're thinking we
need one for each site, but is it better to have the amanda server local to the data it's backing
and have the LUN for the backups remote OR, have amanda server remote to the data and have the LUN
for the backups local.
Would greatly appreciate any thoughts and info all you amanda experts have :)
Hmm. 10TB over WAN? You can calculate what that would take, depending on what your connections are.
Suppose you had a 1Gbps connection between the remote sites. That's 125MBps, which is 7.5GBpm, or
450GBph, or 10.8TBpd. But, you never get 100% utilization of rated speed. So, figure if you had a
1Gbps connection it would take a couple of days (with no competition for the bandwidth) to get a
full backup.
Now, plug in what you really have for bandwidth, what portion of that bandwidth is in use for other
purposes, and project how long it might take.
From that, figure out what portion of the whole would make sense to try to do a full backup of at
one shot. Then divide up your total storage into enough pieces (DLE's) so that none of them are
larger than that. Then come up with a plan that sets your dumpcycle to a number of days so that
you'll be able to spread the fulls out over the dumpcycle and actually accomplish them within a
single run along with incrementals of all the other DLE's.
That's sort of a starting point for thinking about it. Once you have details about how much actual
data is on those systems, what your bandwidth is, what the current utilization of the bandwidth is,
and how fast/frequently your data changes; then, I'm sure there will be more concrete/detailed
suggestions for how to handle it.
--
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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
