Veritas-bu

[Veritas-bu] Performance Problems

2007-01-12 22:26:33
Subject: [Veritas-bu] Performance Problems
From: ewilts at ewilts.org (Ed Wilts)
Date: Fri, 12 Jan 2007 21:26:33 -0600
On 1/12/2007 3:54 PM, Martin, Jonathan (Contractor) wrote:
> I'm finally getting around to performance tuning the new hardware and my
> hair is now officially on fire.  To say the storage is slow, is like
> saying the south pole is chilly.  Performance is TERRIBLE.  Not just in
> Netbackup, but generally speaking I can't copy files to these volumes at
>30MB/sec.  

It appears you've done the first step and eliminated NetBackup from the 
picture since you say that performance is terrible outside of NetBackup. 
  Start with some standard benchmarks like iometer so that you can 
duplicate the tests as you make changes.

> NBU 6.0 MP4 on Windows 2003 MP1

This is now irrelevant.  You said you've got a performance issue outside 
of NetBackup.  Get that fixed first.

> Dell PowerEdge 2950s w/ Dual Core Xeon 3.2 Ghz Processors 4GB Ram
> Storage - Dell MD1000 w/ 15 7,200RMD SATAII Drives

SATA is designed for capacity, not performance.

> 1 - Dell is floating the idea that because my memory runs at 667Mhz and
> my FSB runs at 1066Mhz that it could be causing a traffic jam.  Anyone
> put any stock in this idea?  They suggest 533Mhz RAM which fits much
> more nicely with the 1066FSB.

That sounds like somebody doesn't know what they're talking about. 
There's no way that the memory differences are going to make *that* much 
of a difference.

> 2 - Anyone using NTFS compression on DSUs or DSSUs > 500GB?  I realise
> you take the compression hit on 4KB NTFS Cluster sizes and compression
> speeds, but I want to know if its possible to use NTFS on a volume and
> gert descent read/write speeds from a DSU / DSSU.

You would take a massive performance hit on the CPU.  Don't try it until 
you have the hardware working properly to start with, and then you can 
tweak from there.

> 3 - I'm assuming my best transfer speeds are going to be NBU 

Remember, you've already eliminated NetBackup.  Leave it alone for now.

 > on a 14 Disk Raid5 array w/64KB Stripe.  I guess its possible 
multiples of 64KB would be ok as
> well.

That RAID-5 set is *way* too large.  Don't forget that for every RAID-5 
write, you're going to have to read from the remaining 13 members to 
calculate the parity.  Given the reliability of SATA drives, you're also 
setting yourself up for failure of the array due to a double-disk 
failure.  At a minimum, create 2 separate RAID-5 sets.  Ideally, keep 
your RAID-5 sets to 4 or 5 members.

> 4 - From some perspectives it looks just like the hardware isn't moving
> data fast enough.  But I guess its also fair to say that NBU isn't
> driving the hardware to move the data any faster.  With the exception of
> Buffer settings is there anyway to shift the NBU I/O realted processes
> into "high gear?" Increasing the buffer sizes and adding more buffers
> only help until a certain point.

I googled a bit and ran across an article 
(http://forums.storagereview.net/index.php?showtopic=23323) that said:
"I'm currently testing the Dell PERC 5/E, based on the Intel IOP333, and 
it's pushing over 510MB/s read STR and 314MB/s write STR with 14 Fujitsu 
MAX3036RC drives in RAID 5. The drives are connected through a SAS 
expander with a 1,2GB/s wide port between controller and expander. The 
database performance of this setup is truly stunning (I can post some 
benchmarks if anyone is interested)."

That looksl ike it's using SAS drives so I don't think you're maxing out 
the controller.

So...start with benchmarks, and then follow up with the Windows and 
storage tuning folks.  Once you've got Windows writing at the 
performance it should be, then worry about NetBackup tuning.

        .../Ed
-- 
Ed Wilts, Mounds View, MN, USA
mailto:ewilts at ewilts.org


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