Sizing of Oracle with SAN

[Daemegil]

I plan to install some Oracle Database servers 9i on VMWare ESX 3.5. I use an EMC CX3-10 SAN. I want to split the installation into three parts on the SAN : Oracle software / Database / logs.

My questions :

- is it a good idea for performance / availability in accessing my data ?

- Should i use vmfs for those the 3 Luns i want to create ?

- If my system partition is sized at 10 GB, My data 50 GB and my logs 10GB how much space should i count on the luns (20 GB / 100 GB / 20 GB for snapshots ?)

- If i install 4 Oracle servers, should i create 4x3 = 12 LUNS ?

Thank you for your answers

[petedr]

When I ran an Oracle environment as Virtual Machines we did a similar layout except everything was on local storage, we didn't have a SAN.

We did seperate vmdks,

O/S

Oracle software ( Oracle Home )

Database Files ( if you want to split the logs out that works too ).

One thing we did was put a copy of the control file on every vmdk.

For free space on your LUN for snapshots etc I think 10 to 15 % free is probably good.

[mike_laspina]

Hi,

From a performance perspective I see 5 important aspects.

1) The total number of drives in an array has the greatest impact on its performance. (more spindles = more units of work = best performance) (Raid 5)

2) The separation of LUN's between DB and LOG will greatly improve the performance and reliability.

3) Partition alignment and block size matching is key to good performance on VMFS volumes.

4) VM based snapshots are not a backup. They are a temporary method of backup provisioning to the final backup solution. e.g. Tape or Disk

5) vmdk's perform very similar to RDM's 1-2% better on RDM

RDM's will make it possible to snapshot the LUN on the SAN so you may what to consider it depending on your need for speed.

In your case the data volume size is small so its not very appealing.

http://www.vmware.com/pdf/esx3_partition_align.pdf

[petedr]

Here is a the vmware page on Oracle and VMware with various links discussing running Oracle with VMware.

http://vmware.com/partners/virtualize_oracle_landscape.html?q=oracle%20vmware

[mikemast]

I would reccomend running the oracle software on RAID 5 for high Read I/O. The log files and any data files that have allot of writing to them put them on RAID1_0.

We have seen a dramating increase in respose time by diviving up or mount points this way. By using RAID 5 for high read I/O and RAID 1_0 for the High writing I/O. These are all on Fiber 15k RPM drives also.

Mike M.