Ryan,
As several other have started to point out, you will probably hit the wall
on network performance long before SCSI performance. We are using Quad 480
MHz E450s for media servers. During testing, using Oracle test files copied
from one of my data base servers we were able to write 17.9 MB/sec EACH to
all twelve AIT-2 drives simultaneously on an ADIC Scalar 1000s from just one
E450. The file was local to the E450 though, those test files were
compressible, and the drives were being fed by dd, not NBU. The test was of
the CPU/SCSI chains, not the software.
To do that in real life during backups would require the network delivering
214.8 MB/sec (over 2 and 1/8 GbE running at wire speed). I have not been
able to get any of my Suns to deliver over 54.2 MB/Sec consistently (on a
single GbE) yet. I am hoping to find the secret tuning combination soon
(perhaps the new Cassini GbE cards). The extra tape drive and SCSI capacity
in the servers/libraries is useful for vaulting though. If you followed the
demultiplexing discussion, you find you need lots of drive-hours to de-mpx
lots of images....
Neil
PS - The E450s have some substantial internal bus advantages over the
workgroup servers with fewer PCI-UPA bridges (e.g. E220/E420/E250). The UPA
interrupt distribution improvements in the US-III based systems like the
V880 may give them an even larger advantage.
-----Original Message-----
From: veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu]On Behalf Of Ryn
Sent: Thursday, November 01, 2001 6:26 AM
To: Veritas BU
Subject: [Veritas-bu] DLT and media server concern
Howdy folks,
I am trying to devise a solution to backup 1.5 terabytes of data each night.
What solutions
are most of the folks on the list using for similar configurations? We are
debating sticking
in a switched gigabit ethernet network, two media servers and four DLT8000
drives per
media server. The media servers will be Sun 220/420/250/450/280s. Has anyone
devised
a similar solution? By any chance does anyone have throughput figures from
the
220/420/250/450?
I am curious how many drives it will take to saturate the bus. Also, are
there
any calculations
that need to be done to determine RAM/CPUs per system???
Thanks for any suggestions/thoughts/past experiences.
- Ryan
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