4k-HDDs with ZFS (Advanced Format)

[schlitzohr1812]

Hey folks.

Planning to build up a nice FreeNAS 8-Server using ZFS RaidZ1.

I wonder whether FreeNAS can handle HDDs with 4k sectors correctly (also known as "Advanced Format").

And what about mixing 512Byte-sector HDDs with 4k-HDDs in one RaidZ-Volume?

Thx in advance :)

greetz

 

[Tekkie]

First of all welcome :)

Second please search the forums before posting ;) this particular horse was beaten to death in several threads already.

As for mixing 512B and 4KB it won't matter to the system as the sector size is a low level setting, however performance will probably be at the 512B lvl vs. a pure 4KB setup.

 

[schlitzohr1812]

Hey. Thx for your answer.

I already searched the forum but did not really found a definite answer.

Just found lots of people having problems with 4k-drives...


1) I read that there is a 4k-Checkbox somewhere (maybe only in beta-rls??)? Do I have to check that box?

2) And what about the "compatibility-jumper" on some advanced-format-HDDs? Use it or not

So what do i exactly have to do when I want to create one big raidz1-volume using four 512-byte-sector drives and two 4k-sector drives ?

Thx a lot.

greetz

 

[parks853]

I've been doing a lot of searching my self for the same answers. Hopefully others will correct me if I'm wrong.

1. This I'm sure about - from 8.0.1 BETA and on there is a jumper for building volumes with 4K sectors.

2. Seems the WD EARS drives have the compatibility jumper to perform like a 512b sector drive (never seen anyone mention it for the popular samsung drives).

People were claiming good performance with 8.0 RELEASE using compatibility mode on their drives. However, others were claiming slightly better performance with 4K sectors checked (BETA only for now), drives without the jumper. Going by what tekkie mentioned above your system will probably perform at the 512 level since you have a mixed system. Do your drives have the jumper? Seems like you would be okay to create a volume as 512 and use the compatibility jumper if you have it.

Hopefully someone else will chime in as I'm still learning my self. The advice I'm giving my self is take it slow and don't put any valuable data on the drives until I completely understand the system. i figure it will save losing data or having to store it off somewhere.

 

[Tekkie]

Hey. Thx for your answer.

I already searched the forum but did not really found a definite answer.

Just found lots of people having problems with 4k-drives...

Problems is the wrong word I think, before the 8.0.1 betas the option didn't exist in FreeNAS8.

1) I read that there is a 4k-Checkbox somewhere (maybe only in beta-rls??)? Do I have to check that box?

This check box exists in 8.0.1-B1 onwards and will appear when you create a new ZFS volume, this info exists in multiple threads. ;)

2) And what about the "compatibility-jumper" on some advanced-format-HDDs? Use it or not

Only use this if you want to force a 4KB drive to present itself as a 512b drive

So what do i exactly have to do when I want to create one big raidz1-volume using four 512-byte-sector drives and two 4k-sector drives ?

Use any of the FreeNAS8 releases just don't tick the 4KB check box when creating the volume, that's it.