I'm sorry, I didn't realize the Monterey Bay Aquarium Research Institute in 
coordination with freebsd.org was the authority on internet etiquette. I was 
simply trying to encourage poor Bart here to achieve NetBackup success by 
ignoring certain comments that imply such success isn't possible. In the 
future, I'll consider your internet sensibilities before telling you to go to 
hell.

-Jonathan

-----Original Message-----
From: Conner, Neil [mailto:neil AT mbari DOT org] 
Sent: Friday, June 25, 2010 12:02 PM
To: Martin, Jonathan; WALLEBROEK Bart; Veritas List
Subject: Re: [Veritas-bu] Destaging going slow

Jonathan,

We all appreciate the collaborative benefit of list participation, including
yours.  But do us all a favor please, and take your personal issues offline.


http://www.freebsd.org/doc/en/articles/mailing-list-faq/etiquette.html

Thanks. 


On 6/25/10 8:49 AM, "Martin, Jonathan" <JMARTI05 AT intersil DOT com> wrote:

> Great.  I would say that is your "baseline", and that is just about what I get
> out of 15x1TB SATA disks in a Raid-5 at 8 streams. What kind of Raid
> controller are you using?  What kind of block sizes on that raid volume? What
> kind, and how many physical disks are in your raid set? Is this a SAN or DAS?
> If it is a SAN, do you have other things on the same raid group? Are you using
> / what are your values in the touch files? Have you looked at your disk
> counters while the destaging is running? (Logical and Physical disk counters
> for individual disks.) Are you seeing high levels of disk queuing? Does your
> throughput to tape match the read/sec?
> 
> 35-40 MB/sec is not ideal, but I could consider it acceptable if you were
> using huge SATA disks. If you think you are not getting the performance you
> deserve from the hardware then I would suggest digging.  It took me two weeks
> to find the optimal settings that I run now.  In the mean time, don't listen
> to Ed.  There are plenty of users on this forum who have DSSUs running just
> fine. I for one have something like 12 sites running DSSUs without issue.
> 
> -J
> 
> -----Original Message-----
> From: WALLEBROEK Bart [mailto:Bart.WALLEBROEK AT swift DOT com]
> Sent: Thursday, June 24, 2010 11:19 PM
> To: Martin, Jonathan; veritas-bu AT mailman.eng.auburn DOT edu
> Subject: RE: [Veritas-bu] Destaging going slow
> 
> Martin,
> 
> Even when we fully format the DSSU disk and we then run 1 backup job to this
> disk and directly afterwards we duplicate it to tape we get these speeds
> (35-40MB/sec).  So at that time no fragmentation at all is involved.
> 
> Best Regards,
> Bart WALLEBROEK
> Backup Admin & Systems & Applications Management & Support Specialist 
> Enterprise Applications Delivery - Infrastructure Management
> 
> -----Original Message-----
> From: Martin, Jonathan [mailto:JMARTI05 AT intersil DOT com]
> Sent: Thursday, June 24, 2010 5:34 PM
> To: WALLEBROEK Bart; veritas-bu AT mailman.eng.auburn DOT edu
> Subject: RE: [Veritas-bu] Destaging going slow
> 
> I regularly push LTO3 to 100+MB/sec. It just depends on your configuration
> (hardware and software.) For example, I've got a 4TB Oracle DB that writes to
> a DSSU at 40MB/sec then destages to tape at 100+MB/sec.  I understand that you
> are running 1 deduplication job at a time to a single tape drive.  How many
> concurrent backups are you writing to the DSSU? That is where the
> "fragmentation" comes from. It's not so much fragmentation, as non-contiguous
> files that cause the majority of my speed issues.
> 
> -Jonathan
> 
> -----Original Message-----
> From: WALLEBROEK Bart [mailto:Bart.WALLEBROEK AT swift DOT com]
> Sent: Thursday, June 24, 2010 2:46 AM
> To: Martin, Jonathan; veritas-bu AT mailman.eng.auburn DOT edu
> Subject: RE: [Veritas-bu] Destaging going slow
> 
> Jonathan,
> 
> Actually we already tried out different sets of block sizes on the DSSU.  32
> seems to be the fastest we can find.  We do not use compression and there is
> no fragmentation whatsoever (newly formatted disk).  Only 1 duplication is
> done at a time (only 1 tape drive attached to the DSSU Media Server) while no
> backups are pointing to the DSSU while we perform the destaging.
> 
> But so far no luck.  Could this be due to the backend disk system where the
> DSSU disk is located on ?  Although we see some impressive speeds when backing
> up files from DSSU to that same tape drive.  We use an HP XP 20000 (Hitachi).
> 
> Best Regards,
> Bart WALLEBROEK
> Backup Admin & Systems & Applications Management & Support Specialist 
> Enterprise Applications Delivery - Infrastructure Management
> 
> 
> -----Original Message-----
> From: Martin, Jonathan [mailto:JMARTI05 AT intersil DOT com]
> Sent: Wednesday, June 23, 2010 3:59 PM
> To: WALLEBROEK Bart; veritas-bu AT mailman.eng.auburn DOT edu
> Subject: RE: [Veritas-bu] Destaging going slow
> 
> Format your DSSUs with a 64k block size.
> Use 64K block size on raid group.
> Disable compression (if you can't use 64k block size.)
> Lower the number of concurrent writes to the DSSU.
> Occasionally "clear" the DSSU to relieve fragmentation.
> 
> Clear the DSSU, write a single backup to the disk, then stream the backup to
> tape. Whatever performance you get from that single stream is the best you are
> going to get from that configuration.  Any additional concurrent writes will
> likely slow your performance.
> 
> We had a lively discussion on this topic a few weeks back. Here's a link to a
> post I made about fragmentation and wet blankets.
> 
> http://www.adsm.org/lists/html/Veritas-bu/2010-05/msg00029.html
> 
> -Jonathan
> 
> -----Original Message-----
> From: veritas-bu-bounces AT mailman.eng.auburn DOT edu
> [mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of 
> WALLEBROEK
> Bart
> Sent: Wednesday, June 23, 2010 9:23 AM
> To: veritas-bu AT mailman.eng.auburn DOT edu
> Subject: [Veritas-bu] Destaging going slow
> 
> We have a couple of windows (dedicated) Media Servers that act as NetBackup
> DSSU (Disk Staging Storage Unit) servers with each having from 4 to 16 TB of
> SAN disks.  Backing up to them is no issue and goes up to the limit of the
> network connected clients.  Destaging to tape (LTO4) however is slow (20 - 35
> MB/sec).
> 
> We have been in contact with Symantec where they advised us to lower the
> fragment size, change the data buffers size and numbers but we seem to get
> stuck to the current speed.  Backing up data from this DSSU disk to the tape
> drives goes up to physical tape speed limitation.
> 
> Does anyone have an idea where to look further to get to a reasonable speed ?
> 
> We currently are testing a Solaris DSSU server but we do not have numbers for
> that one.
> 
> Best Regards,
> Bart WALLEBROEK
> Backup Admin & Systems & Applications Management & Support Specialist 
> Enterprise Applications Delivery - Infrastructure Management
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> _______________________________________________
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