The 64k limit was due to a tcp/ip stack
limitation
I have always found larger buffers (256k)
generally provide the best performance.
Only if you had lots of small files would I
recommend anything less
Flashbackup will definitely improve your
performance as the data will not need to be uncompressed prior to passed to the
backup device.
The only factor to consider is that
flashbackup will also backup the blocks on the drive which are empty – so
you backup the entire volume.
I am going to guess you wont see much
performance going to disk as you issue is probably not at the backup target as
you have a collection of LTO4 drives.
A single LTO4 should be able to backup
that entire volume in 6 hours easy – even if the SAN is running at 2GB.
Can you share any info about your disk
config?
Is it SAN or internal storage?
How many disks are in the config?
If you run Windows perfmon how are your
disk queues looking?
Also – how many split I/O’s
are you getting? – ensuring proper file system / volume partition can
make a decent difference
Do you have bad disk fragmentation?
All things that can make a difference . . .
.
From:
veritas-bu-bounces AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of Nic Solomons
Sent: 16 September 2010 14:44
To:
veritas-bu AT mailman.eng.auburn DOT edu
Subject: Re: [Veritas-bu] Real
World NBU Buffer settings Win2k3
Also worth noting that
for 2003+, if you don’t have specific RTOs for individual files, you can
do volume based backups with your standard licensing (but no individual file
restore).
http://seer.entsupport.symantec.com/docs/275912.htm
Which should give you
the same performance boost as flash backup.
Make sure you use VSS
though – not VSP (why they left the screenshot like that, no idea).
Cheers,
Nic
From:
veritas-bu-bounces AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of Martin, Jonathan
Sent: 16 September 2010 14:23
To: WEAVER, Simon (external);
William Brown; veritas-bu AT mailman.eng.auburn DOT edu
Subject: Re: [Veritas-bu] Real
World NBU Buffer settings Win2k3
Windows is a piece
of cake.
Install the client.
Select Policy Type:
Flashbackup-Windows
Setup Selection
List: \\.\R: (change drive letter as required)
Run Policy
Enjoy monumentally
faster backups (on compressed volumes)
You cannot backup
the system drive (C:) or System
State with Flashbackup. I
normally run these in a 2nd “OS” policy.
Be sure to test a
restore. You can do “entire volume” restores, which are just as
fast as backups. Or, you can restore individual files.
-Jonathan
From:
veritas-bu-bounces AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of WEAVER, Simon (external)
Sent: 15 September 2010 19:00
To:
veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] Real World
NBU Buffer settings Win2k3
Hi All
Anyone got any real world experience on buffer settings:
scenarion:
Win2k3 San Media, connected to 2GB Fabric attached 8 LTO4
Drives.
Due to drive availability, Multiplexing onto one drive.
Main problem: One volume (1,7tb in size) takes over 4 days to
fully complete.
Got the Tuning Guide and Technote 244602, but I tried some
settings, only to find the backup would not even mount tape correctly.
So back to "no" settings at the mo.
Volume are generic files/folders, mixture of large and small
sizes. But 1.7TB's in my view should be done quicker. Also Data is compressed.
Regards
Simon
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