ASM disks

[nanoux]

Hi, I have a question on creating raw devices for ASM luns.

what if you create the raw device based on one of the legacy path instance...Will it be sufficent for multi-path feature?

What if that particular lun path goes down..will the same luns be available via other paths.

I was told that using the dsf path instance to create the raw devices would be the best to support multi-pathing?

Can I have some expert comments on the above claims.

[Juan Antonio Llano]

Hy,

on 11.31 i use the /dev/rdsk/hdisk4 path, but in any case if you are going to use legacy devices or 11.11/23 i prefer to use lvm/slvm and give asm lvm raw devices, this way with pv links i have rebundancy.

[Duncan Edmonstone]

I'm assuming your question relates to an 11iv3 (11.31) host.

You can use either the legacy or the agile DSF as you choose, however if you use the legacy DSF, you will need to ensure that the attribute "leg_mpath_enable" is set to true for that LUN. You can check this with scsimgr, e.g.

scsimgr get_attr -D /dev/rdisk/disk19 -a leg_mpath_enable

SCSI ATTRIBUTES FOR LUN : /dev/rdisk/disk19

name = leg_mpath_enable
current = true
default = true
saved =


As long as it is set to true then the storage stack will do multi-pathing even on the legacy DSF.

I have to ask *why* you don't want to use the new agile DSF - you're creating challenges for yourself if you don't... what's the problem with using ASM_DISKSTRING="/dev/rdisk/disk*" instead of ASM_DISKSTRING="/dev/rdsk/*"

HTH

Duncan

[nanoux]

Thanks Duncan, that was a clear explanantion.

Will use agile dsf to in future.

[nanoux]

I have assigned points to al of you anyway.thanks.