RAID 10 using Freenas 9.2

[Kakou]

Hello !

I would like to have more details about making a RAID10 under freenas 9.2

From the documentation I've read this:

to extend a ZFS mirror, add the same number of drives. The resulting striped mirror is a RAID 10. For example, if you have 10 drives, you could start by creating a mirror of two drives, extending this mirror by creating another mirror of two drives, and repeating three more times until all 10 drives have been added.

So if I understand well, I have to make a first ZFS mirror with 2 HDD, then extend it by adding a new ZFS mirror of 2HDD ?

I've 4 WD Red 4TB

Thank you!
Marc

 

[Yatti420]

Why not just run a raidZ2 versus mirroring etc..

 

[Kakou]

I wanted to go with a RAID10 instead of Raidz2 for several reasons:
- upgrade a raid10 is easier than a raidz2 (just need to add 2 more disk)
- raid10 is faster that raidz2
- I know that raidz2 is safer than raid10, but it's for home use, I don't need that much safety

 

[Ericloewe]

I wanted to go with a RAID10 instead of Raidz2 for several reasons:
- upgrade a raid10 is easier than a raidz2 (just need to add 2 more disk)
- raid10 is faster that raidz2
- I know that raidz2 is safer than raid10, but it's for home use, I don't need that much safety

a) is a dubious advantage
b) is irrelevant in home use, as well as most enterprise use. Easy saturation of GbE is guaranteed in nearly all cases.
c) Data integrity is more important at home, where bulletproof backup strategies might not be in place. "I don't need that much safety" should only be said if you're not going to lose anything important (just some DVD rips, for instance).

 

[gpsguy]

You can do this in one step, using ZFS Volume Manager. See message #4 in this thread.

So if I understand well, I have to make a first ZFS mirror with 2 HDD, then extend it by adding a new ZFS mirror of 2HDD?

If you value your data, backups are a neccessity, whether you are using mirrors or RAIDz2/3.