Merge 2xz1 raids to 1xz2 ?

[Anton Palmgård]

Hi , As the topic states i want to merge 2 set of raids.

When i first made this setup i had 3x3tb and 3x4tb which i merge using both in the same volume.

Now the last 3tb failed so i now have 3x4tb + 3x4tb and obvisously i want to merge these for higher security.

Is it possible ?

I have spare disks so i could add 3x4tb temporary to one of the raids if thats needed to move the data.

What's my best option to keep all data ?

atm i'm at 8tb usage.

Thanks in advance.

Br,
Anton

 

[danb35]

There isn't a way to directly convert a RAIDZ1 volume to RAIDZ2--what you'd need to do would be back up your data, destroy the pool, recreate it as 6x4TB RAIDZ2, and then restore the data. If you're only using 8 TB, you could set up a separate pool of 3 x 4TB RAIDZ1 for the backup, and it would have room for almost all of your data. Depending on how your data is stored, you might be able to back up about 5% of it to a client computer, and use ZFS replication to back up the rest from one pool to the other.

 

[Anton Palmgård]

I see, but out of curiosity if i remove 1 of the raids does the volume still exist with the data the raid that is left is holding or will the volume be unavailable ?

BR,
Anton

 

[danb35]

Once you have added a vdev to your pool, it cannot be removed. If any vdev in a pool fails (e.g., by having more disks fail than the redundancy can tolerate), the entire pool will be unavailable.

 

[Anton Palmgård]

I see well then i wont be making such volumes anymore..
Since i only have 8 sata ports on my Lsi-card i guess i have to remove 1 drive in both arrays then create a array with 4 disks.

Could it be done like this, i create a raid with 4x4TB z1(1spare). When the backup is done could i extend that raid with 1 more disk storage disk and then 1 more spare ? So that it would end up as 4x6 z2 ? or wouldn't i be able to convert that array either ?

I mean there are several standard bay-nas that support that kind of change. Where you start with 2 drives and 2 spares and in the end its 8 drives 2 spares.

Thanks for your help much appriciated.

Br,
Anton

 

[cyberjock]

No. Please read my noobie guide. It explains what you can and can't do with vdevs. ;)

 

[Anton Palmgård]

I see, "a VDev cannot be extended with more disks" to bad.

1 more question while we're at it. Why wont raid5 / z1 protect you ? What happens when you add a new spare ? I thought it will only sync the data to the new drive. Not rearrange the whole thing ?

"So the read fails. And when that happens, you are one unhappy camper. The message "we can't read this RAID volume" travels up the chain of command until an error message is presented on the screen. 12 TB of your carefully protected - you thought! - data is gone."

Even if a rebuild to the new drive fail because of URA , the rebuild shouldnt corrupt the data on the working drives there for the data is not gone and a backup to a new array is possible ? What am i missing ?