The core is a 6905 Cisco backbone 128GB backplane... everything is on Gig 
ports... the backups that went to tape came across a two nic team on the master 
server and a two nic team on the media server.  We have added four more nics on 
each server in three teams.  The DSU has 12 one gig-e connections.  The data 
has been strategically placed across the 12 ports/shares so all the data 
doesn't come from just one system housing DSUs.  The same core pushed the 
muliplexed tapes drive to around 60 Gb/hr... the same amount of data is coming 
in.. .now just across a wider pipe to single threaded tape drives.  The data 
flies going into the DSU.

Thanks,
Jim

[quote] I'm assuming you went from a media server attached to a fiber channeled 
tape drive to a media server attached to a network attached disk 
appliance - depending on your core backbone I would say that is your 
performance degradation. How many hops to the DSU?, are the ASIC's over 
subscribed?, stuff like that is where I would start 




Tim Needham, Sr. Backup Engineer 
Apollo Group | Information Technology | Data Protection 


-----Original Message----- 
From: veritas-bu-bounces < at > mailman.eng.auburn.edu 
[mailto:veritas-bu-bounces < at > mailman.eng.auburn.edu] On Behalf Of jkearns 
Sent: Monday, July 27, 2009 2:17 PM 
To: VERITAS-BU < at > MAILMAN.ENG.AUBURN.EDU 
Subject: [Veritas-bu] Vaulting images from disk = slow tape speed, 
ideas??? 


We backup about 16Tb of data over the course of a weekend. We used to 
run NBU 6.0 MP2 with four LTO3 drives fiber connected. We recently 
changed to NBU 6.5.3 and a disk to disk appliance... we now vault from 
the disk images (DSU) to tape for offsite storage and DR. By my 
estimates the drives used to copy at roughly 62 Gb/Hr multiplexed. So 
we would be finished over the course of a weekend. Now that we are 
vaulting from disk to tape, the tape drives cannot multiplex from disk 
to tape. My vault jobs take extremely long to finish and if a drive is 
busy when the vault job begins then it only runs on the remaining 
available tape drives (which for us, we have two tape storage groups 
with two drives in each one based on what master/media they belong to) 
so when something happens to one drive I end up copying images for half 
of my environment to one tape drive. The drive non-multiplexed are 
copying at about 30-35 Gb /Hr. Moving to a disk replication would solve 
this but my DR 
plan is a cold site so I have to keep tape. Is there anything I can 
do to improve this performance?

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