Jeff,
I can't really say, since you have the Flash SAN. I'm assuming you have
excellent bandwidth between the DB server and the SAN, so Flash Cache might
make no difference. I'd think it *might* IF you had an SSD locally on the
server itself and configured Flash Cache to use it. That would eliminate any
traffic latency and perhaps any SAN contention - which may be used by other
servers?.
You can turn it on and off pretty easily so it might be worth testing it for
your situation. After turning it on, give it a few days to become fully
populated to get the maximum advantage of the largest Flash Cache part of the
Buffer Cache. I'd be *very* interested in any results of that testing.
--
Jack C. Applewhite - Database Administrator
Austin I.S.D. - MIS Department
512.414.9250 (wk)
I can't help about the shape I'm in,
I can't sing, I ain't pretty and my legs are thin.
But ... -- "Oh Well" F.M.
________________________________
From: Jeff Chirco <backseatdba@xxxxxxxxx>
Sent: Wednesday, March 22, 2017 11:12:49 AM
To: Jack Applewhite
Cc: oracle-l@xxxxxxxxxxxxx
Subject: Re: Additional CPU justification
HI Jack, yep we are moving to Oracle Linux 7. We already have a NetApp All
Flash SAN which this database runs on and yeah it is basically eliminated most
I/O wait. Would this Database Smart Flash Cache still be beneficial?
Thanks
On Tue, Mar 21, 2017 at 2:29 PM, Jack Applewhite
<jack.applewhite@xxxxxxxxxxxxx<mailto:jack.applewhite@xxxxxxxxxxxxx>> wrote:
Jeff,
If you're going to Linux you should consider Oracle Linux. Also, get some SSDs
for that server. The huge performance improvement of implementing Database
Smart Flash Cache is available under Oracle Linux and Solaris - only those two
OS's.
We have two X5 ODAs with a lot of Prod DBs on them. Each ODA node (server) has
256GB of RAM, 20 cores lit up, with one shared 512GB SSD per ODA. Our main Prod
DBs are running on the the two nodes of one of the ODAs, each with about a 50GB
SGA.. They were straining the ODA nodes at times - Load Averages of up to 80 or
so (which is 400%), with a lot of that being I/O waits.
We turned on Flash Cache and have been utterly stunned at the performance
improvement for each DB. We rarely have L.A.'s over 20 (100%) anymore. Flash
Cache extends the Buffer Cache to the SSD and manages it. We've seen waits on
DB File Sequential Read go way, way down.
As you know memory and disk are much, much cheaper than Oracle CPU licenses.
SSDs have come way down. Licensing Oracle Linux looks like a fairly inexpensive
proposition, though I haven't done so standalone - OL is just part of the ODA
package, which we love.
Hope this helps.
--
Jack C. Applewhite - Database Administrator
Austin I.S.D. - MIS Department
512.414.9250<tel:(512)%20414-9250> (wk)
I can't help about the shape I'm in,
I can't sing, I ain't pretty and my legs are thin.
But ... -- "Oh Well" F.M.
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx>
<oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx>> on behalf
of Jeff Chirco <backseatdba@xxxxxxxxx<mailto:backseatdba@xxxxxxxxx>>
Sent: Tuesday, March 21, 2017 3:07 PM
To: oracle-l@xxxxxxxxxxxxx<mailto:oracle-l@xxxxxxxxxxxxx>
Subject: Additional CPU justification
Hi everyone, I am working on trying to make a case that our production database
server needs some additional CPU's but was hoping you might be able to give me
some tips/suggestion that you've used to prove your case. We are a smaller
shop and so we currently only have a 2 CPU database license and so the cost of
doubling that plus all the packs and options we have is not an easy thing to
pass.
We currently running 11.2.0.4 on Windows but plans to move to Oracle Linux this
year and possibly 12c at that time.
We occasionally spike to 80-100% during the day but average around 40%
Thanks for any help.
Jeff
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