Unity Vault Drive Copyback

Hi Momosk,

Apologies if my post was misleading. You are correct.

I should have said the drive becomes free, not spare. Although in the GUI it will show as a spare drive.

There is one exception though: A vault spare drive can serve as hot spare for another failed vault drive.

- Let's say we have a pool built on 0_0_0 0_0_1 0_0_2 1_0_0 1_0_1

- For some reason, the only spare drive on the array (of the same type) is 0_0_3 for example.

- If 0_0_1 fails, it will trigger a copy to 0_0_3

- In this case, the pool would become 0_0_0 0_0_3 0_0_2 1_0_0 1_0_2

- 0_0_1 becomes a spare drive (or free) after replaced.

This is the only exception as the drive user space is the same for both.

The documentation refers to this scenario:

- We have a pool built on 1_0_0 1_0_1 1_0_2 1_0_3 1_0_4

- For some reason, the only spare drive on the array (of the same type) is 0_0_3 for example.

- If 1_0_0 fails, there will be no rebuilds and an error is sent saying there are no suitable spares to replace the drive.

  This is because the user space on a normal drive is larger than it is on a vault drive.

- Once a suitable spare becomes available on the system, the rebuild will be triggered.

The automatic copy back on a unity OS drive only effects the OS portion of the drive. To copy back the user data, you need to open a service request and quote knowledge article kb498463. An unused OS drive can not be used as an available spare.

Very nice explanation its clear . I have one question We have unity 350F and as you its all flash drive having no dedicated hot spare i replace one failed disk and please let us know does unity perform copy back operation to rebuilt drive ...?

Hello sayed.zuber,

In most cases when a drive is replaced the data is copied back to the replacement drive even if you don’t have a hotspare configured.