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Home -> Community -> Mailing Lists -> Oracle-L -> RE: db datafiles on NetApp FAS940 filer
John,
Thank you for the excellent info.
I only put app tablespace datafiles on the NAS filer, everything else is on the local disks of a Sun V880 box running SunOS 2.8 64-bit.
I've run identical sets of direct inserts on identical tables in both tablespaces on local disk and on NaS and I found the inserts to take about 10% longer time on NAS. The biggest problem was sporadic "freezes" which I think is because the ethernet cable to the filer or the underlying buses are not configured well or something like that.
>>> john.kanagaraj_at_hds.com 2/10/2004 6:51:06 PM >>>
Carmen,
A number of good points have already been said. I would like to add a
word
of caution in addition: NetApp uses WAFL - Write Anywhere File Layout.
Basically, what this means is that that updates to existing blocks are
written to the NetApp 'disks' as _new_ blocks, leading to some
interesting
side-effects. If your Application is write-intensive (including writes
to
TEMP on account of Hash joins, sorting, etc. as well as writes to
Rollback
and Redo which can get intensive), you will find that the Disk space
consumed auto-magically blooms very quickly indeed. A NetApp
'snapshot'
apparently puts this all back, releasing space by replacing the older,
updated blocks with the newer versions (apparently by cleverly updating
an
internal inode structure). Based on this, you will have to very
carefully
configure your snapshotting frequency. I do not know the internals of
NetApp
and the overhead of configuring and executing these snapshots, so
YMMV.
So... As an outsider, I would suggest that you place the Control files,
Redo
Logs, TEMP, RBS (or UNDO TBS) and other *update*-intensive objects on
Direct
Attached Storage (or SANs if you can manage that) to mitigate this,
and
press the NetApps folks to carefully consider snapshotting. Note that I
did
not mention Archive logs or temporary staging areas in this list - the
disk
blocks being written in this case aren't *updates* to existing disk
blocks
[NAS Gurus - please correct me if I err!]
OTOH, you might want to consider a combined SAN-NAS configuration
(seems
this is becoming available), where you will be able to get a SAN that
will
support I/O intensive apps while also serving out NAS via NetApp. You
should
then be able to get some SAN space for the above files and some NAS
space
for the rest.
John Kanagaraj
DB Soft Inc
Phone: 408-970-7002 (W)
Disappointment is inevitable, but Discouragement is optional!
>-----Original Message-----
>From: oracle-l-bounce_at_freelists.org
>[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Joze Senegacnik
>Sent: Tuesday, February 10, 2004 12:31 PM
>To: 'oracle-l_at_freelists.org'
>Subject: RE: db datafiles on NetApp FAS940 filer
>
>
>Carmen,
>I know one unhappy customer with NetApp. This customer is using Baan.
>The average wait time for I/O is:
>
>db file sequential read 13.7ms
>db file scattered read 17.9ms
>
>The response time in average consists of: 15% of service time
>and 85% of
>wait time due to slow I/O. They complain that the average CPU
>load is only
>15-20%. They have also problem with unhappy final users. The
>supplier tried
>to improve the performance but with no major change. If
>somebody would ask
>me for the advice about NetApp I wouldn't recommend it.
>
>Joze
>
>
>-----Original Message-----
>From: Carmen Rusu [mailto:carmen.rusu_at_rrc.state.tx.us]
>Sent: Tuesday, February 10, 2004 8:55 PM
>To: oracle-l_at_freelists.org
>Cc: Carmen Rusu
>Subject: db datafiles on NetApp FAS940 filer
>
>
>
>I am experimenting with creating tablespaces/datafiles on a new
NetApp
>filer we got installed.
>
>The sysadmin configured a dedicated volume out the the 9tb behemoth
>with a stripe size of 128k, which he tells me is what tech support
told
>him to.
>
>Anybody on the list with a NetApp storage device with Oracle on it?
How
>did you configure it? Wha kind of performance do you get? Any
caveats?
>
>Thanks,
>
>Carmen Rusu
>DBA
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-- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html ----------------------------------------------------------------- ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line. -- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Wed Feb 11 2004 - 07:58:54 CST
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