Re: ASM and VMWARE

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Fri, 14 Jun 2024 19:47:42 -0400
Message-ID: <e00e343a-bcee-47cb-8350-15a60c213648_at_gmail.com>

Thanks Osman.
   I'm familiar with the information you provided, but I would like to know if
these same guidelines apply to VMWARE, and EMC.

Thanks again.

ed

O

Ed, ASM is a volume manager, just like lvm2, which is by default installed on every Linux server box. Volume manager and hypervisor do not interact very strongly. My first question is why would you use ASM in a VM? If the hypervisor is on the premises, you can create RAC database, although the purpose of that would be unclear since there can be no high availability if all the machines are running on the same hardware. Once upon a time, Mogens Norgaard, an Oracle employee at the time, wrote an article named "You Probably Don’t Need RAC" which is an obligatory read for any DBA. The article was written as a reaction to Oracle pushing RAC as a solution to all problems, even warts and acne. Well, that trend is still continuing. RAC under hypervisor makes no sense whatsoever. Once we have established this fact, the question is what do you need ASM for in a VM? Modern file systems like XFS or F2FS (Ext4 modified for SSD devices) can do both direct and asynchronous IO and can achieve the same performance as ASM. That also allows you to offload most of the underlying work to a system administrator. You don't have to get involved with growing a file system.

Regards

-- http://www.freelists.org/webpage/oracle-l Received on Sat Jun 15 2024 - 01:47:42 CEST