Chip-

I have never tried this for backups (we use all FC for backups), but our
broadcast group has several V880's with gig ethernet (quad I believe) and
they have had lots of success with trunking.  This seems viable since you
would only be scaling your current solution.  You might ask your SUN rep
about this or do a www search...

my 2 cents,

Steve Curry
Yahoo! Inc.



-----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 Chip
Paswater
Sent: Tuesday, December 17, 2002 9:29 PM
To: veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] Ethernet Bottleneck - need design suggestions


Hey folks,

I'm having some bottleneck issues with my backup design.  Here's the
scenerio:

1 Sun E4000 with 8CPU 8GB and single gigabit ethernet
ADIC Scalar 1000 Tape Library with 8 LTO drives
LTO Drives are capable of 15MB/sec
Sun and TL are both connected to SAN fabric via 2 connections each

So the connection from the Server to the library is not the bottleneck.  I
have 4 drives going down 1 fibre path and 4 down the other.  Considering
1gb FC can do 100MB/sec, and an LTO drive does 15MB/sec, that means a max
througput of 60MB/sec per FC port.

However, when doing a network backup, all data has to come through the
single
ethernet port on the E4000.  Sun loocks their MTU rate of their gig ethernet
cards at 1500, so max bandwidth comes to around 440mbits/sec.  This means a
max theoretical throughput of around 50MB/sec, obviously not enough to push
data to 8 LTO drives simultaneously.

So how do I scale the solution to open the ethernet bottleneck?  Veritas is
not being forthcoming with a solution, and I can't seem to find any best
practices documents on their site with any insight.

Should I consider trunking ethernet to my Extreme switches?

What about running a media server but controlling the robot from the master?

Has anyone had any experience with Vertias's claim that they can do "SAN
direct" backups?  ie,Direct Server -> TL over FC without using IP over FC

_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu