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Good testing,
=20
Have you tried RAID 10 / (1/0) or tried (0+1) ?
=20
________________________________
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
=20
"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.=20
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=20
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=20
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=20
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).=20
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=20
> > around 300-500KB/s.
> >
> > NUMBER_DATA_BUFFERS =3D 16
> > NUMBER_DATA_BUFFERS_DISK =3D 16
> >
> > SIZE_DATA_BUFFERS =3D 262144
> > SIZE_DATA_BUFFERS_DISK =3D 1048576=20
> >
> > 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=20
> > 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=20
> 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=20
>
--
-Tim
_______________________________________________
Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
=20
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<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>Good =
testing,<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>Have you tried RAID 10 / =
(1/0) or
tried (0+1) ?<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<div class=3DMsoNormal align=3Dcenter style=3D'text-align:center'><font =
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face=3D"Times New Roman"><span style=3D'font-size:12.0pt'>
<hr size=3D2 width=3D"100%" align=3Dcenter tabindex=3D-1>
</span></font></div>
<p class=3DMsoNormal><b><font size=3D2 face=3DTahoma><span =
style=3D'font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font =
size=3D2
face=3DTahoma><span style=3D'font-size:10.0pt;font-family:Tahoma'>
veritas-bu-admin AT mailman.eng.auburn DOT edu =
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu]
<b><span style=3D'font-weight:bold'>On Behalf Of </span></b>Dean<br>
<b><span style=3D'font-weight:bold'>Sent:</span></b> Sunday, August 14, =
2005 5:15
AM<br>
<b><span style=3D'font-weight:bold'>To:</span></b> Tim Berger<br>
<b><span style=3D'font-weight:bold'>Cc:</span></b> Matt Clausen;
veritas-bu AT mailman.eng.auburn DOT edu<br>
<b><span style=3D'font-weight:bold'>Subject:</span></b> Re: [Veritas-bu] =
Fast
backup to tape but slow backup to disk on NBU =
5.1MP3</span></font><o:p></o:p></p>
</div>
<p class=3DMsoNormal><font size=3D3 face=3D"Times New Roman"><span =
style=3D'font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal style=3D'margin-bottom:12.0pt'><font size=3D3
face=3D"Times New Roman"><span style=3D'font-size:12.0pt'>"Matt, =
writing
multiple concurrent streams to the same set of disks may<br>
be hurting performance. One at a time may yield better =
results."<br>
<br>
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. <br>
<br>
<o:p></o:p></span></font></p>
<div>
<p class=3DMsoNormal><span class=3Dgmailquote><font size=3D3 =
face=3D"Times New Roman"><span
style=3D'font-size:12.0pt'>On 8/12/05, <b><span =
style=3D'font-weight:bold'>Tim
Berger</span></b> <<a =
href=3D"mailto:tim.berger AT gmail DOT com">tim.berger AT gmail DOT com</a>>
wrote:</span></font></span><o:p></o:p></p>
<p class=3DMsoNormal><font size=3D3 face=3D"Times New Roman"><span =
style=3D'font-size:
12.0pt'>Matt, writing multiple concurrent streams to the same set of =
disks may<br>
be hurting performance. One at a time may yield better =
results.<br>
<br>
I'm in the process of building out some staging servers myself for =
nbu<br>
5.1 - been doing a bunch of bonnie++ benchmarks with various configs<br>
for Linux using a sata 3ware controller.<br>
<br>
On fedora core 3 (I know it's not supported):<br>
<br>
Raid5, 5 disks I got ~30MB/sec writes & 187MB/sec =
reads. Raid 50
with <br>
striping over 3 4-disk raid5's got 49MB/sec writes, 120 MB/sec =
reads.<br>
For raid0, w/10 disks, got a nice 158 MB/sec writes, and 190MB/sec<br>
reads.<br>
<br>
I'm partial to raid5 for high availability even with poor write <br>
performance.. I need to stream to lto3, which tops out at 180
MB/sec.<br>
If I went with raid0 and lost a disk, then a media server would take =
a<br>
dive, backups would fail, and I'd have to figure out what data failed =
<br>
to make it off to tape. I'm not sure how I'd reconcile a lost =
dssu<br>
with netbackup. If I wanted to to use the dssu's for doing =
synthetic<br>
fulls, then that further complicates things if a staging unit is =
lost.<br>
<br>
Any thoughts on what the netbackup fallout might be on a dssu loss?<br>
<br>
Even though it's not supported yet, I was thinking of trying out<br>
redhat enterprise linux 4, but I'm seeing really horrible disk<br>
performance (eg. 100MB/sec reads for raid5 vs the 187MB/sec on fc3). =
<br>
<br>
Maybe I should try out the supported rhel3 distribution. =
;-) I<br>
don't have high hopes of that improving performance at the moment.<br>
<br>
On 8/10/05, Ed Wilts <<a =
href=3D"mailto:ewilts AT ewilts DOT org">ewilts AT ewilts DOT org </a>>
wrote:<br>
> On Wed, Aug 10, 2005 at 12:43:39PM -0400, Matt Clausen wrote:<br>
> > Yet when I do a backup to disk, I see decent performance<br>
> > on one stream (about 8,000KB/s or so) but the other streams =
will drop
to <br>
> > around 300-500KB/s.<br>
> ><br>
> > NUMBER_DATA_BUFFERS =3D 16<br>
> > NUMBER_DATA_BUFFERS_DISK =3D 16<br>
> ><br>
> > SIZE_DATA_BUFFERS =3D 262144<br>
> > SIZE_DATA_BUFFERS_DISK =3D 1048576 <br>
> ><br>
> > and I see this performance on both the master server disk pool =
AND a<br>
> > media server disk pool. The master server is a VxVM concat =
volume set
of<br>
> > 3x73GB 10,000RPM disks and the media server is an external =
raid 5
volume <br>
> > of 16x250GB SATA disks.<br>
><br>
> I don't believe you're going to get good performance on a 16 =
member<br>
> RAID5 set of SATA disk. You should get better with a =
pair of 8
member<br>
> raid sets, but SATA is not fast disk and large raid 5 sets kill you =
on <br>
> write performance. If you're stuck with the SATA drives,
configure them<br>
> as 3 4+1 RAID5 sets and use the 16th member as a hot
spare. You'll have<br>
> 3TB of disk staging instead of about 3.8TB but it will perform a =
lot <br>
> better.<br>
><br>
> --<br>
> Ed Wilts, Mounds <st1:place w:st=3D"on"><st1:City =
w:st=3D"on">View</st1:City>,
<st1:State w:st=3D"on">MN</st1:State>, <st1:country-region =
w:st=3D"on">USA</st1:country-region></st1:place><br>
> mailto:<a =
href=3D"mailto:ewilts AT ewilts DOT org">ewilts AT ewilts DOT org</a><br>
> _______________________________________________<br>
> Veritas-bu maillist - <a
href=3D"mailto:Veritas-bu AT mailman.eng.auburn DOT edu">Veritas-bu AT mailman
DOT eng.=
auburn.edu</a><br>
> <a =
href=3D"http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu";>http:/=
/mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
</a><br>
><br>
<br>
<br>
--<br>
-Tim<br>
<br>
_______________________________________________<br>
Veritas-bu maillist - <a
href=3D"mailto:Veritas-bu AT mailman.eng.auburn DOT edu">Veritas-bu AT mailman
DOT eng.=
auburn.edu</a><br>
<a =
href=3D"http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu";>http:/=
/mailman.eng.auburn.edu/mailman/listinfo/veritas-bu</a><o:p></o:p></span>=
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