2 Disk RaidZ

[clusty]

I recently got 2x 14TB disks to replace my dying pool made from scrap disks I had lying around.
I configured it as Raid-Z. While I know it does not make sense now and that Mirror is better, it would make expansion easier.
Is there a particular reason why this was not supported in UI ? ( I had to create the pool from the command line)

 

[Heracles]

RaidZ expansion is not yet...

So here, you have to go with mirror. As for expansion, it will be easy to create a second mirror when ready and add that mirror in the pool.

 

[clusty]

RaidZ expansion is not yet...

So here, you have to go with mirror. As for expansion, it will be easy to create a second mirror when ready and add that mirror in the pool.

I am not sure i can live with the disk wastage :)
This pool will grow to 8 disks at some point and I guess the final config would be a raidz2

That is 25% waste vs 50%
My current pool is made of mirrors.

 

[Patrick M. Hausen]

You will have to recreate the entire pool each time you add one or more disks. One does not simply add disks to a RAIDZ vdev. Never supported, probably at some time in the future, but nobody can tell you, when exactly.

 

[clusty]

You will have to recreate the entire pool each time you add one or more disks. One does not simply add disks to a RAIDZ vdev. Never supported, probably at some time in the future, but nobody can tell you, when exactly.

I am still keeping the hope alive :)
The feature is already live in my fantasy world. I know i will be probably disappointed if the feature gets canned after exposing all the bugs in the spaghetti code.

 

[Patrick M. Hausen]

The feature is beimg worked on, so not all hope is lost. But it's not a solution right now. I would not build a strategy based on it.

 

[MrGuvernment]

I am not sure i can live with the disk wastage :)
This pool will grow to 8 disks at some point and I guess the final config would be a raidz2

That is 25% waste vs 50%
My current pool is made of mirrors.

Don't think of it as waste.. think of it as performance depending on your usage, and data security possibly...(assuming you have proper backups and if the data is even critical enough you care to protect it)

 

[Whattteva]

I would not rely on RAIDZ expansion as a strategy cause you will just be disappointed. These things have to be tested thoroughly due to the mission-critical nature of file systems. Look at BTRFS, over a decade and they still can't get RAID right without corrupting people's files. Just imagine how many thousands of RAID fantasies have been shattered in all that time. So many people were excited about BTRFS as the filesystem that was supposed to finally unseat ZFS and also have a license that's more compatible with Linux's GPL.

Just in case this wasn't clear. RAIDZ is NOT backup. I know a lot of people here probably treat them as such, but that's just a recipe for tears and the forums have many instances of such posts of people weeping over the loss of their precious data.

 

[Etorix]

I am not sure i can live with the disk wastage :)

Hope you can live without your data then, because that's where "2-disk raidz" (degraded 3-wide raidz1, I assume) is leading you.

This pool will grow to 8 disks at some point and I guess the final config would be a raidz2

Changing raidz level is not, and has never been, part of the plan for vdev expansion. The only way from raidz1 to raidz2 is, and will remain, "backup, destroy, recreate, restore".