Score:3

Increasing RAID1 (mirror) redundancy in HP Smart Array P410?

vu flag

Please is it possible to add a third (or more) drives to a mirror (RAID1) in P410? IIUC it would mean creating "Mirror Group 3" (or more). I could not find any way to add a new mirror group using the HP tool ssacli, the documentation only talks about expanding capacity of the mirror (i.e. adding drives to existing mirror group/s), not about increasing redundancy (i.e. creating new mirror groups). Also google search for "Mirror Group 3" returned no results.

My intention is to add a drive, finish recovery/resync, and eventually to remove one of the old drives, all while running the OS using the ssacli tool. Basically replacing the old drives with new ones while keeping redundancy all the time.

cn flag
`replacing the old drives with new ones` of the same capacity? Why are you doing that?
Pavel Hofman avatar
vu flag
E.g. to use a new drive with a new lifetime. The existing logical drive capacity is more than sufficient for the given use case. Thanks.
Score:2
kz flag

It's not possible. What you can do however is to switch your RAID card into HBA mode and use Linux MDRAID or ZFS three-way mirrors. HP P410 is an "el cheapo" RAID, so software RAIDs would give you better performance either way (+ZFS will provide you with an on-the-fly meta and metadata integrity checks).

Pavel Hofman avatar
vu flag
Thanks. Do I understand correctly then that the P410 is only capable of 2-drive mirrors? I use MDRAID and ZFS on other servers, but this one is a machine I cannot re-install at will.
BaronSamedi1958 avatar
kz flag
Yes, this is correct. Two-way mirror.
I sit in a Tesla and translated this thread with Ai:

mangohost

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.