How to install RAID5 with different size disks and then extend it

[jbesclapez]

Hi guys,

Here is my plan.
I have 3 disks of 10+10+8 terras
I want to create a RAID5 out of that of 16Gb.
Then I want to take away the 8 disks.
I will then copy the data from another 10 Terra disks to the RAID5
Once the data are copied and stored on the RAID5 I will add the new 10 Terra disk to the RAID5.
At the end I will have 3 disks of 10+10+10.

How can I do that?
I tried to create a pool of RAID-Z but it is different no? And then can it be extended?

Basically i have data on the 3rd drive with 10T that i need to keep.
In total i have 10+10+10+8 but ultimately i would like a RAID5 of 10+10+10 without lossing my data on my actual 10. (cant ovewrite)

Thanks

 

[Patrick M. Hausen]

You cannot do that.

You can:

- create a RAIDZn of disks of different size, you will only get capacity according to the smallest disk
- replace the smaller disk(s) with larger ones, the capacity will increase

You cannot:

- add disks to a RAIDZn vdev later.


You should probably read the ZFS primer first, to get familiar with the concepts. And please stop using terms like RAID5. There is no such thing in ZFS. Which leads back to the ZFS primer I figure

27. ZFS Primer — FreeNAS®11.3-U3.2 User Guide Table of Contents

www.ixsystems.com

 

[jbesclapez]

Basically I have da

You cannot do that.

You can:

- create a RAIDZn of disks of different size, you will only get capacity according to the smallest disk
- replace the smaller disk(s) with larger ones, the capacity will increase

You cannot:

- add disks to a RAIDZn vdev later.


You should probably read the ZFS primer first, to get familiar with the concepts. And please stop using terms like RAID5. There is no such thing in ZFS. Which leads back to the ZFS primer I figure

27. ZFS Primer — FreeNAS®11.3-U3.2 User Guide Table of Contents

www.ixsystems.com

Hi Patrick! Thanks for your feedback.
I am a total noob in FreeNas as you can see. I am computer litterate and did ran a synology and then made my own xpenology for years, but the level of technicity for FreeNas is a lot higher. To be honest I was not expecting it like that...
I think I will go for a RAIDZ as i do not think I will ever loose more than 1 drives at the same time - If I understand correctly it is the equivalent of RAID5.

Thanks Patrick, but seriously, once again you got me thinking if I should move to FreeNas... it looks a lot more complicated. Luckily there are people like you around!

 

[sretalla]

I think I will go for a RAIDZ as i do not think I will ever loose more than 1 drives at the same time

Just to be clear, you are running without redundancy as soon as 1 disk is removed or failed.

Resilver operations are stressful on all pool members while a disk is in replacement and with 8 or 10 TB disks, you're talking 24 hours + of resilver time in addition to whatever time it takes you to get from removed/failed to replacing/resilvering.

100% your choice, but we in the forum recommend not to put yourself under that kind of stress if you love your data.

At one point in the possible future, RAIDZ expansion will be available allowing you to add a 4th (or further subsequent) disk to the original 3 (but you will be locked to RAIDZ1 for that pool/VDEV forever, so choose wisely if you do select FreeNAS)