SOLVED Does Running a Server With the ZFS HDDs Disconnected Damage The ZPool?

[Terrigat]

While I am waiting for an RMA to go thru on 1 of 6 in a RaidZ2, I wanted to detach my ZPool HDDs entirely (remove power lead) and run entirely on the backup drives (a separate RAID5 of 4 hdds) instead of running them in a degraded state.
Do I need to run an export / import for this first or can I just detach them until the new drive comes in?


EDIT: found out that the original Oracle documentation [http://docs.oracle.com/cd/E19253-01/819-5461/gbbzy/index.html] does tell you the answer to this question.
Also, if I have a failing drive in a ZPool, is there a way to copy the data over to a replacement drive to avoid the rebuild? The replace command does this? I assume it either replaces the drive and rebuilds OR copies the old drive before detaching it. Didn't see that defined in the MANual and assuming is bad (or so the saying goes).

 

[depasseg]

I don't understand your subject question.

If you detach, you will lose any shares and services associated with that pool. You can do it though.

If you have a drive that you want to replace and can have the old and new drives installed at the same time, then use the replacement directions in the user guide. This will reduce the impact of a full rebuild.

 

[BigDave]

The answer to the title of this post depends on how the drives that make up your volume or volumes are configured.
More information is required please.

 

[Terrigat]

Hoping this is more clear now

 

[depasseg]

It helps. If the drives are disconnected, the pool that's on them will be fine. In fact lots of people do this for off-line/off-site backups. You will receive warnings and freenas will complain that the pool is gone, but it will be ok. Just be sure to shutdown when removing and add the pool, so that freenas knows it isn't and then is there.

 

[BigDave]

I wanted to detach my ZPool HDDs entirely (remove power lead) and run entirely on the backup drives (a separate RAID5 of 4 hdds) instead of running them in a degraded state.

I don't know yet if we are seeing eye to eye. If the backup array is truly RAID5 then NO, if it's a RAIDz1 volume, then YES

 

[depasseg]

Also, if I have a failing drive in a ZPool, is there a way to copy the data over to a replacement drive to avoid the rebuild? The replace command does this? I assume it either replaces the drive and rebuilds OR copies the old drive before detaching it. Didn't see that defined in the MANual and assuming is bad (or so the saying goes).

The system will still do a resilver on the vdev, but since you have't lost the drive yet, it's not in a degraded state. The directions to replace a drive to grow a pool are what you want to do (even though you aren't gowing your pool).
http://doc.freenas.org/9.3/freenas_storage.html#replacing-drives-to-grow-a-zfs-pool

 

[Terrigat]

@depasseg thanks. Glad to know this will be fine.

@BigDave sorry for the confusion. The RaidZ2 is a new Storage array that is literally a copy of an old Mdadm RAID5 that doesn't have any new data yet. Since the new Storage array had a disk that started throwing errors, I RMA'd it. I didn't want to have my newly created and newly degraded array serving data. Was just going to run the old RAID5 in readonly mode until the new drive was in.

 

[pirateghost]

@depasseg thanks. Glad to know this will be fine.

@BigDave sorry for the confusion. The RaidZ2 is a new Storage array that is literally a copy of an old Mdadm RAID5 that doesn't have any new data yet. Since the new Storage array had a disk that started throwing errors, I RMA'd it. I didn't want to have my newly created and newly degraded array serving data. Was just going to run the old RAID5 in readonly mode until the new drive was in.

Uh. You aren't running the old mdadm raid5 setup on FreeNAS....

 

[Terrigat]

Correct.

Trying to get my head around ZFS before learning about FreeBSD and FreeNAS. In a few months after the drives have broken in properly, I will setup a new server. It's the main reason I've avoided CLI & GUI related questions. This is the most active environment to get advice about ZFS for a non-professional.

The old system is an Ubuntu MythTV server I setup years ago. It was my way of learning Linux in a hands on way.

Still remember how long I tried to keep SmoothWall working on an old Pentium III with a bunch of GigaEthernet Adapters. I felt so stupid when I picked up an Asus N12 and put DD-WRT on it.