Performance of servers

[Alzhy]

Alzhy,
>>And we can tell you how large SGAs each of your DB is using. Then you can ask your DBA if it can be >>trimmed down.
on 2nd server run 4 instances as said. 2 ones SGA=6 Gb and PGA=8GB and other 2 ones (datewarehouseâ  s ones) SGA=1.7 Gb and PGA 1.7GB total will be = 34.8 Gb, isnâ  t crazy?

Yikes!

Your server only has 16GB of Memory No? Your ipcs clearly shows 4DB instances whose SGA (shared memory) claim already exceeds RAM!

Have your DBAs please reduce those SGA sizes to total below at least 12GB and you'll have "better" performance.

[Steven E. Protter]

Shalom again,

Oracle pegged to 100%

Joke: Crystal ball is at home.

Reasons why Oracle can be 100%

1) Users are hitting the application to hard and its always doing a lot of I/O. These could be read transactions, but based on your output, I would assume it is write transactions.

2) Poorly written application could be just eating CPU for no good reason or writing inefficient sql requests.

3) Oracle patch could be required.

4) I/O layout of the system could have hotspots. This could include SAN configuration that is raid 5 and needs raid 10, or bad configuration of SAN based LUNS. Need to work with your storage team on that.

How to find out:
Work with the DBA. Have them check oracle statistics. See what is being written where. Look for inefficient sql statements.

Open a TAR with Oracle support. Provide them with data, see what they say.

SEP

[Alzhy]

Rustam Sir,

Here are your 4 Databases as they lay claim to your precious RAM:

m 4882437 0x8cb21ca0 --rw-r----- oratst tdba oratst tdba 33 1627398144 2434 2487 14:55:43 14:55:43 20:19:45
m 32774 0xb8bd04d0 --rw-r----- oratst tdba oratst tdba 52 6459244544 2077 2477 14:54:37 14:54:37 20:18:12
m 7 0xd79db4f4 --rw-r----- oratst tdba oratst tdba 38 1627398144 2256 2482 14:55:12 14:55:12 20:18:52
m 8 0x2b4499fc --rw-r----- oratst tdba oratst tdba 27 6459244544 2633 2484 14:55:23 14:55:23 20:20:13

Your DBA should have a means of telling whether those DB instances (being just test in the first place) do need such amount of SGA.

I bet your stats from sar on paging will exhibit the issue more clearly.

[rustam_2]

I'll come back to this thread in few hours.

[rustam_2]

I've come back. I installed some patches on my server which are newest driver for SAS.
I increased swap area from my HDD (set 24Gb). I know my RAM has little amount still. I told to my chief and he said ok but tell me how many Gb we should buy. I have some questions, could u help me?
1. As you know rx6600 has 48 slots(HP product bulletin says). Now my server has 16 RAM * 1Gb. Can i buy 8Gb or 16Gb RAMs and mixed them? or i must buy only 1Gb RAMs?
2. On server run 4 Oracle instances and about 300 hundred users. Each instances SGA+PGA sizes amount are 15Gbs. Will be enough if i will buy 64 RAM Gb for each other or better to make RAM size 128Gb? In any case i have to give substantiate to my chief.
3. I have 2 processors:
#machinfo
2 Intel(R) Itanium 2 9100 series processors (1.59 GHz, 18 MB)
532 MT/s bus, CPU version A1
4 logical processors (2 per socket)

Should u buy 2 processors or it will be enough?

Best regards,
Rustam

[Alzhy]

The way I am looking at it is you will be safe at least going with 64GB-- that is IF these servers are purely DB Servers and the 300 users are direct connect (no MTS enabled) on the Databases.

Your DBA should be able to tell how much each direct connection to the databaseis memory wise -- or you can actually observe via ps or glance - the process name for those diret connection to the database is something like oracle - for example if your dbname is SAP, the connection process (aka foreground) will be named oracleSAP.