Why have I got a single stripe in my ZFS volume

[Cliff McLoughlin]

Hi All

I am running Freenas 9.3 (with all the latest patches applied) on an HP Proliant microserver booting from USB. This morning I was looking at my ZFS Volume status and noticed that one of disks was labelled as stripe rather than as part of my RAID Z1.

I have 3 questions:

1 How can I have a singe stripe drive? Surely I need at least 2 drives to stripe?
2. Am I right in thinking that any data on this drive has no redundancy and if this drive fails I would lose it?
3. How can I move this drive into the Z1 pool?

Thanks

 

[hugovsky]

Please post your hardware details.

 

[gpsguy]

1) you can have a single drive in a stripe.
2) that's correct. the loss wouldn't be limited to just that drive. you'd lose the entire pool.
3) you can't - you need to backup your data, destroy your pool, and start over

More than likely, you tried to add a drive after you created the RAIDz1 vdev. You can't add a disk to a preexisting vdev.

You can mitigate your current risk by mirroring the single drive. You can't do it via the webGUI. You'd need to do it from the command line. Instructions for doing it, can be found on the forum.

 

[Cliff McLoughlin]

HP Proliant N54L,
AMD Turion(tm) II Neo Dual-Core Processor
10GB RAM,
5x2TB HDD
FreeNAS-9.3-STABLE-201505040117

I should have said I'm an advanced Windows user but very much a FreeNAS/LINUX noob

Anything else I'm missing?

 

[Cliff McLoughlin]

Thanks

When I'm running a scrub on Main and look at the disk activity there is very little on the stripe drive

Is there any way I can see what's stored on it (if anything) and remove it from the pool without losing data? I don't have enough storage to transfer all my data (i.e. back-up my ZFS data). I assume when you say mirroring the the stripe, you mean adding another disk and mirroring it. I can't do this as I have no additional drive slots/SATA ports free

 

[gpsguy]

No, as I said before, you can't remove the disk, since it's a member of your "Main" pool.

Yes, you'd create a mirror by adding another drive. With your N54L, one can squeeze 6 disks into them. With the right adapter, you can stack 2 drives in the ODD bay and utilize the eSATA port on the back.

When you added the 5th drive, did you install one of the hacked BIOS's? If not, that drive and the eSATA (if you were using it), would be performing like an IDE drive. The hacked BIOS's allow you to use these drives at full speed.

 

[Cliff McLoughlin]

Yes I installed the hacked BIOS, so at least I did that bit right:)

I suspect you're right and when I replaced a disk I managed to stripe it. I do remember having problems with a disk and finding the interface confusing - if I remember I hit replace rather than offline but I may have rebuilt the whole FreeNAS subsequently.

Most of what I have running on the FreeNAS is backups so I guess I can take the risk of rebuilding for a couple of days. Is there any way to export/backup jails or will I have to reinstall them from scrtach?

Thanks again for all the help

 

[cyberjock]

What's the output of "zpool history Main"?

That will have date/time stamps, and will surely tell you the precise date/time that the stripe was created. I'm betting you had this idea that you can add single disks to the zpool, so you added one thinking it would add to the vdev (they don't). This was the main reason for my noobie guide (and is explained thoroughly there).