Re: raid 10 vs. ASM

steph schrieb:
> Hi group,
>
> A simple question, I hope it's not too general to get an answer ...
>
> We set up a new database-server, 10G R2 Standard Edition One on Linux,
> 4 discs.
>
> Our sysadmin proposed configuring the discs as raid 10, my original
> plan was to go with 2 raid 1 groups using ASM. What are the pros and
> cons of each solution?

Striping won't cost I/O performance if done by software, so in terms of performance there won't be much difference. The only question I'd ask myself is what's easier to manage, raw devices or asm?

Also, are the four disks all you've got in the machine or do you have other disks for the OS and software?

ASM *really* comes into its own if you have lots of disks and io capacity to spare. Then you let asm manage the redundancy with the advantage of asm automatically rebalancing when a disk becomes unavailable. So, whereas in a Raid10 config it takes two dead disks for your db to be toast, in a no raid asm config, asm is supposed to rebalance until it runs out of disks or disk capacity.

To those IO buffs in this group, does software mirroring cost a lot of IO bandwidth?, that is, can the CPU-controller path take twice or trice the real IO load without getting slower than the controller-disk path(s)?

Lots of Greetings!
Volker Received on Thu Apr 20 2006 - 09:11:04 CDT