Hot spare and RAID 1+ 0 question with VA

[Vincent Abad]

Hello All,

i'll need your expertise!.
We plan to use VA7410 with native
RAID 1+0 mode to maximize IO load.
I have some question regarding the HA of our solution.
Someone suggest us that we do not need to use hot spare disk into the array with this configuration.
In case were "autorebuid is set to on" , my comprehension is that when a disk fail, as there is no hot spare, the array will be not able to rebuild data, so that leave data vulnerable for a long period.?
Or in other way the array use the unused capacity (if any) across all the disk to redistribute data?

Thanks for your help,

--Vincent

[Sijesh]

Hi Vincent,

RAID1+0 rebuld will happen only after replacing the defective drive. When autorebuld is enable Array does the rebuld with out a user command.

Sijesh

[Arend Lensen · Accepted solution]

Hello Vincent,

I don't understand a word of what Sijesh replied and will give you some details.
When the array is running in raid-01 mode you can indeed do this without having hotspare enabled. What the array does in case of a disk failure is moving as much data to raid-5 as needed to complete the rebuild. This can take a lot of time but it will complete!. After that you can replace the disk and then the array will start to balance this is a "reverse-rebuild" and it will again migrate the data back to raid-01.
I hope this is an answer to your question.

Regards,
Arend