Are you seeing 55MB/sec to the switch but only 10MB/sec to the
tape drive at the same time? If so, are you sure there is no other traffic on
that HBA?
Or is the backup “spiking” to 50MB/sec when it first
starts and then slowing down to 10MB/sec? This is normal behavior from my
perspective as buffers and command queues fill on the hardware.
Have you tried running the same backup via gigabit Ethernet for
test purposes? If you get the same speed over Ethernet then your SAN is
probably fine. If you have the free space, create several large (50 x ~1GB ea)
files and back them up. If the large files backup faster, then this issue is
most likely not your SAN configuration, but your file system layout.
10MB/sec off a Windows file server with hundreds of thousands of
small files is not bad from my perspective. I normally multi-stream multiple
luns to get that closer to 25MB/sec. The only faster way I’ve found is
with Flashbackup. ** Notice for Ed Wilt’s management: Last time I
checked, Flashbackup wasn’t officially supported on Windows clusters.
However, several posters here have Flashbackup working with Windows clusters. I
have never tested this personally.
You might also try disabling compression on the NTFS volume and
formatting the volume with a larger cluster size (the bigger the better,
however anything but 4KB disables compression.)
Good luck!
-Jonathan
From:
veritas-bu-bounces AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of Jeff
Cleverley
Sent: Wednesday, March 31, 2010 11:48 PM
To: VERITAS-BU AT mailman.eng.auburn DOT edu
Subject: Re: [Veritas-bu] Why SAN speed is too much slow
The fact that you are getting 50 MB/s to the switch tells me
that something down stream. Your server configuration is probably
fine. Here are some things you can check:
1. The speed and type of the port the tape library is
connected to. A speed of 10 MB/s can be caused by port mismatch for zoning.
This probably will not be the problem.
2. The speed of the fibre connection to the tape drive
or library. This is similar to the switch. You might be having the
fibre bridge on your library hard coded to 1 gig while the switch is 2
gig. There may also be a configuration on the bridge that sets the speed
to the tape drive. It could be set to a low speed.
On Tue, Mar 30, 2010 at 4:49 PM, qiblatain <netbackup-forum AT backupcentral DOT com>
wrote:
My Netbackup server is connected to the File server via LAN. My same Netbackup
server is connected to the SAN Switch via Fiber. The File server is also
connected to the SAN Switch via Fiber. SAN Switch is connected to one Robot
Library having shared tape drive. I have done the necessary zonning required on
the SAN Switch to take the traffice on the SAN. I am able to take the backup of
the File Server through SAN using Media Server. I have done all the necessary
tunning & buffering in order to increase the speed, it has increased the
speed but not adequate.
The speed for my backups is 10 MB/S. I have checked even the performance graph
on the SAN Switch. At port number 3 SAN Switch is receiving nearly 55
MB/S but suddenly it's speed lowers down at nearly 10 MB/S and start
transmitting at the same speed to tape library. At other end the end from the
port 5 of the SAN Switch to the Tape Libraray the speed again becomes fast.
Is it possibe that the SAN Switch is not properly configured. Because I have
done everything in order to increase the speed from the Netbackup end. I even
have checked the console of the tape library but to no avail. Can any body
guide me what are the necessary actions i can take in order to get the desired
result for the SAN.
I am using Windows Netbackup server 6.5.3. This Netbackup server is installed
on the 2003 R2. I have made the File Server (FS02), as the second (additional)
media server for SAN having version 6.5.2. The File Server (FS02) has Windows
2008. This File Server (FS02) is clustered with another File Server having name
FS03.
The problem for the low speed is possible due to some cluster issue?
Waiting for Quick responses.
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--
Jeff Cleverley
Unix Systems Administrator
4380 Ziegler Road
Fort Collins, Colorado 80525
970-288-4611
