"Extending volumes" - Will this or will it not delete my data?

[sqwob]

I have a running Freenas with data with 4x2TB disks. I'm adding another 4x2TB as a seperate RAIDZ array. They should be available as a big wod of space.

The ui is a bit unclear, the documentation (http://doc.freenas.org/index.php/Volumes#Using_Volume_Manager_After_a_Volume_Has_Been_Created) doesn't really answer my question.

Will clicking this button erase my existing raidZ array, or only the the new disks i'm adding to the zpool?

 

[Stephens]

Make sure you get an answer from someone who 100% knows before you do this. I sure don't 100% know.

1) I'd force 4096 byte sector size.
2) When you add a volume (new vdev in this context), it WILL erase the data on the NEW VDEV disks. That's what the warning is about. It should not erase anything from the vdev you already have.

I wonder if I'll ever get to the place where I'm comfortable enough to try something like this on a live system without a backup (which it sounds like you're about to do). I don't think so. Bugs happen.

 

[ben]

What type of volume are your other four disks in? RAID-Z as well?

That screenshot seems... wrong. It's like it is adding just ad0 as a single disk vdev, which is bad and wrong. I'd say don't press that button, for now. If it was working as intended you would not lose data, but no matter what once you press that the new additions to the volume will be unable to be removed, so it's better to measure thrice.

 

[sqwob]

- I can confirm that it didn't delete my data
- I confirm that in my screenshot i didn't check 4K size, but i did do so when i actually applied the step (thanks for the pointer)
- there was a strange unexpected step when i clicked "Add Volume", asking me to select the raid mode i wanted to use for the new array. I also selected RAIDZ like the first array.

Totals for my available drive space on my (only) Volume have gone up as expected

 

[Stephens]

Cool. Can you post the output of your "zpool status"?

 

[ben]

Oh cool, sounds like the extend method is more different from the normal creation process than it used to be. That sounds like you got it all right, but post the output of 'zpool status' in

Code:

 tags if you don't mind.

 

[sqwob]

and the output of the zpool command:

[root@freenas] /mnt/sata2-Port1-4# zpool status
pool: sata2-Port1-4
state: ONLINE
scan: none requested
config:

NAME STATE READ WRITE CKSUM
sata2-Port1-4 ONLINE 0 0 0
raidz1-0 ONLINE 0 0 0
gptid/fe7b3676-64c9-11e2-9cb5-bc5ff47b3e2f ONLINE 0 0 0
gptid/fef3f97d-64c9-11e2-9cb5-bc5ff47b3e2f ONLINE 0 0 0
gptid/ff694ed6-64c9-11e2-9cb5-bc5ff47b3e2f ONLINE 0 0 0
gptid/ffdb3238-64c9-11e2-9cb5-bc5ff47b3e2f ONLINE 0 0 0
raidz1-1 ONLINE 0 0 0
gptid/76412609-699a-11e2-9c8c-6805ca121aa4 ONLINE 0 0 0
gptid/76ca00e5-699a-11e2-9c8c-6805ca121aa4 ONLINE 0 0 0
gptid/775d2eb1-699a-11e2-9c8c-6805ca121aa4 ONLINE 0 0 0
gptid/77f4fea0-699a-11e2-9c8c-6805ca121aa4 ONLINE 0 0 0

errors: No known data errors

 

[ben]

Looks green across the board!

 

[sqwob]

follow up question: how much disk space would you expect me to have creating this volume this way? it's a tad lower than I expect...

so I have 2 striped - 4 disk RAIDZ array with 2TB drives.

16TB unformatted space
2 parity disks - 4TB
12TB remaining
2 TB = roughly 1.8TBs formatted
so ... 6 data disks = 10.x terrabyte formatted space?

 

[William Grzybowski]

Thats correct. 10.x Tb minus a few gigs for the filesystem structures, etc.

 

[James]

As of 8.3.1, this screen is much clearer when the volume to extend is selected:

http://doc.freenas.org/index.php/Volumes#Using_Volume_Manager_After_a_Volume_Has_Been_Created.

 

[JaimieV]

Typo on that page: "A vdev can be a single disk, a stripe, a mirror, a RAIDZ1, RAIDZ1, or a RAIDZ3."

 

[cyberjock]

Crap! There is a typo on my presentation. I have it fixed and it will be updated when 8.3.1 comes out.