RE: Oracle on Sun T2 performance problems

We seem to have narrowed down the performance issue. The database has a high percentage of LOBs, and the performance problem occurs when using RMAN compression. If I run a RMAN inc0 backup with compressed backupsets on this 150gb database, with 2 channels, it takes 21 hours. With 8 channels it takes 12+ hours and no performance gains are to be had with more than 8 channels. If I turn off compression, I can run the backup in 30 minutes !! The resulting backups are 120gb in size, compared to 68 gb with rman compression. I need to delve into this further.  

David Miller pointed out-

Actually T5220 has one chip that contains 8 cores, each of which has 8 threads.

It looks like 64 cpus to Solaris. There are 8 FPUs on that chip, one per core as mentioned by Bradd.    

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Scott Canaan
Sent: Tuesday, September 23, 2008 4:18 PM To: Crisler, Jon; oracle-l
Subject: RE: Oracle on Sun T2 performance problems  

We've added some Sun T2000 series servers to our data center and they are much slower all the way around. We've done benchmark tests on them to prove it. Basically, you get what you pay for. They are cheaper than other Sun servers. According to one of our SAs, the reason that they are so much slower is that they don't do hardware floating point calculations, it's all software. I've even noticed a 3x to 4x slower transfer rate between servers when using scp if even one of the two servers is a T2000 series. We try to put test databases on them and leave production on the other servers.  

Scott Canaan '88 (Scott.Canaan_at_rit.edu)

(585) 475-7886

"Life is like a sewer, what you get out of it depends on what you put into it." - Tom Lehrer.  

-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Crisler, Jon
Sent: Tuesday, September 23, 2008 4:06 PM To: oracle-l
Subject: Oracle on Sun T2 performance problems  

We are having performance problems with Sun T2 platform, especially with RMAN backups. The database consists of about 75% blobs.  

Has anybody run into major performance problems with RMAN either on a Sun T2 or on a 10g db with lots of blobs ? Our disk I/O has far more i/o capacity than is being used.

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