How does that throughput value change if you increase the number of jobs
righting to the volume?
Paul
> -----Original Message-----
> From: veritas-bu-admin AT mailman.eng.auburn DOT edu
> [mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu] On Behalf Of
> Tim Berger
> Sent: August 15, 2005 2:02 PM
> To: Eric Ljungblad
> Cc: Dean; Matt Clausen; veritas-bu AT mailman.eng.auburn DOT edu
> Subject: Re: [Veritas-bu] Fast backup to tape but slow backup
> to disk on NBU 5.1MP3
>
>
> For a 6 drive 10 raid, I got about 140MB/sec reads & 95MB/sec writes.
> It's a shame that it takes so many disks to get good write performance
> on a redundant raid.
>
> These are all 400GB SATA disks.
>
> On 8/14/05, Eric Ljungblad <Eric.Ljungblad AT copleypress DOT com> wrote:
> >
> >
> >
> > Good testing,
> >
> >
> >
> > Have you tried RAID 10 / (1/0) or tried (0+1) ?
> >
> >
> >
> > ________________________________
> >
> >
> > From: veritas-bu-admin AT mailman.eng.auburn DOT edu
> > [mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu] On Behalf
> > Of Dean
> > Sent: Sunday, August 14, 2005 5:15 AM
> > To: Tim Berger
> > Cc: Matt Clausen; veritas-bu AT mailman.eng.auburn DOT edu
> > Subject: Re: [Veritas-bu] Fast backup to tape but slow
> backup to disk on
> > NBU 5.1MP3
> >
> >
> >
> >
> > "Matt, writing multiple concurrent streams to the same set
> of disks may
> > be hurting performance. One at a time may yield better results."
> >
> > I believe Tim's got it right. SATA is best at serial
> writes. If you feed it
> > two or more streams, that is effectively random writes, and
> performance
> > suffers badly.
> >
> >
> >
> >
> > On 8/12/05, Tim Berger <tim.berger AT gmail DOT com> wrote:
> >
> > Matt, writing multiple concurrent streams to the same set
> of disks may
> > be hurting performance. One at a time may yield better results.
> >
> > I'm in the process of building out some staging servers
> myself for nbu
> > 5.1 - been doing a bunch of bonnie++ benchmarks with
> various configs
> > for Linux using a sata 3ware controller.
> >
> > On fedora core 3 (I know it's not supported):
> >
> > Raid5, 5 disks I got ~30MB/sec writes & 187MB/sec reads.
> Raid 50 with
> > striping over 3 4-disk raid5's got 49MB/sec writes, 120
> MB/sec reads.
> > For raid0, w/10 disks, got a nice 158 MB/sec writes, and 190MB/sec
> > reads.
> >
> > I'm partial to raid5 for high availability even with poor write
> > performance.. I need to stream to lto3, which tops out at
> 180 MB/sec.
> > If I went with raid0 and lost a disk, then a media server
> would take a
> > dive, backups would fail, and I'd have to figure out what
> data failed
> > to make it off to tape. I'm not sure how I'd reconcile a lost dssu
> > with netbackup. If I wanted to to use the dssu's for
> doing synthetic
> > fulls, then that further complicates things if a staging
> unit is lost.
> >
> > Any thoughts on what the netbackup fallout might be on a dssu loss?
> >
> > Even though it's not supported yet, I was thinking of trying out
> > redhat enterprise linux 4, but I'm seeing really horrible disk
> > performance (eg. 100MB/sec reads for raid5 vs the
> 187MB/sec on fc3).
> >
> > Maybe I should try out the supported rhel3 distribution. ;-) I
> > don't have high hopes of that improving performance at the moment.
> >
> > On 8/10/05, Ed Wilts <ewilts AT ewilts DOT org > wrote:
> > > On Wed, Aug 10, 2005 at 12:43:39PM -0400, Matt Clausen wrote:
> > > > Yet when I do a backup to disk, I see decent performance
> > > > on one stream (about 8,000KB/s or so) but the other
> streams will drop
> > to
> > > > around 300-500KB/s.
> > > >
> > > > NUMBER_DATA_BUFFERS = 16
> > > > NUMBER_DATA_BUFFERS_DISK = 16
> > > >
> > > > SIZE_DATA_BUFFERS = 262144
> > > > SIZE_DATA_BUFFERS_DISK = 1048576
> > > >
> > > > and I see this performance on both the master server
> disk pool AND a
> > > > media server disk pool. The master server is a VxVM
> concat volume set
> > of
> > > > 3x73GB 10,000RPM disks and the media server is an
> external raid 5
> > volume
> > > > of 16x250GB SATA disks.
> > >
> > > I don't believe you're going to get good performance on
> a 16 member
> > > RAID5 set of SATA disk. You should get better with a
> pair of 8 member
> > > raid sets, but SATA is not fast disk and large raid 5
> sets kill you on
> > > write performance. If you're stuck with the SATA
> drives, configure them
> > > as 3 4+1 RAID5 sets and use the 16th member as a hot
> spare. You'll have
> > > 3TB of disk staging instead of about 3.8TB but it will
> perform a lot
> > > better.
> > >
> > > --
> > > Ed Wilts, Mounds View, MN, USA
> > > mailto:ewilts AT ewilts DOT org
> > > _______________________________________________
> > > Veritas-bu maillist -
> > Veritas-bu AT mailman.eng.auburn DOT edu
> > >
> > http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
> > >
> >
> >
> > --
> > -Tim
> >
> > _______________________________________________
> > Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
> > http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
> >
> >
>
>
> --
> -Tim
>
> _______________________________________________
> Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
>
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