Hot Diggety! Levinson, Donald A. was rumored to have written:
> has anyone deployed TSM from a B50 or a 43p 140 ?
> I need to back up about 4 GB a night on a local network from 2 clients and
> maintain a total tape pool of about 2.5 TB on about 100,000 objects or less.
A B50 is just a repackaged 43P-150 in a rack mount case. It's (either one -
the B50 or 150) is a very capable machine.
Only limitation to the B50 is that it is not "slots-happy" ;) Has only two
expansion slots so you have to choose *VERY* carefully with what and how you
expand it... and it also can not support gigabit ethernet adapters --
presumably due to the fact it's a 32 bit machine.
Doing some quick calculations shows 8 GB/night to be about 8.3 MB/sec for
about 8 hours which means about 70 Mbps on the network -- which would just
barely saturate a fast ethernet network.
You would be *highly* advised to add a second FE network adapter to the B50
and split the clients -- point half of the clients towards one B50
interface and the other half towards the second FE interface.
Ie:
backup1.foobarbazz.com points to 10.1.1.1
backup2.foobarbazz.com points to 10.1.2.1
(and both IPs would be individual IPs on each ethernet interface...
would put both on separate IP subnets such as a class C or /24
because this would prevent return traffic from hogging one primary
outgoing interface.)
On half of your clients, point them to backup1 in dsm.sys, on other
half, point to backup2 in dsm.sys, etc. How do you decide which clients
to split up? Do it based on data volume for backed up data.
If one client does 50% of the data traffic and 99 clients does 50% of the
data traffic, then that's how you'd split it up.
I would not recommend the use of a 140 because IIRC, it's a PReP based
machine and I think AIX 5.2 dropped support for these? The current
generation RS6Ks and pSeries servers are CHRP based, including the 150 and
B50.
Also, if you can daisy chain your tape drive(s) off the onboard SCSI
adapter for the B50, that might work... but you would most likely want
to have a diskpool and split the SCSI bus between disks and tapes; which
implies adding a second SCSI adapter for the B50, using up its second
expansion slot (first would be for another FE adapter).
Otherwise you could end up with a serious performance bottleneck that
could totally negate whatever the B50 is capable of handling.
It's also uniprocessor which could potentially mean some CPU contention
for various resources (tapes, disks, network, cpu) when it's busy.
In short, the B50 should work out ok, but you appear to be quite pushing
the very limits of its packaging for your _current_ needs, nevermind
long-term future growth needs.
You would be highly advised to get a slightly beefier machine, or at least
a machine with more PCI slots than the B50.
Right now, the next step up above the B50 would be the pSeries 6C1 or 6C4,
at about double to triple the cost of the B50. Unfortunately, we have not
found any other intermediate range machines between these.
I do use a B50 for some TSM testing so I know it works fine as long as you
don't try to push more data through it than what its adapters can handle.
-Dan
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