Replace cache & log disk

[AxelTwin]

Hi everyone,

I have one ssd drive split in 2 with log & cache configured on it.

Is it safe to take it offline and replace it with a bigger one ?

Any particular things I need be cautious with ?

 

[dignus]

Yes, you replace it safely, but first remove the log & cache from your pool, then replace the disk and add them again.

 

[LnxBil]

I recommend to NOT use cache (as of L2ARC) and use a special device with metadata instead. This will yield faster pool times

 

[Dunuin]

I recommend to NOT use cache (as of L2ARC) and use a special device with metadata instead. This will yield faster pool times

Jup, but that at least as a mirror nd not with the slog on the same disks.

 

[AxelTwin]

thnaks for those usefull informations.
I will buy a second disk and setup seperate cache using special device.

 

[Dunuin]

cache using special device

Special device is no cache. Lose your special devices and all data is lost.

 

[dignus]

Actually.. I setup my special devices in 3. Except when they're optane, then I use 2.

 

[leesteken]

Actually.. I setup my special devices in 3. Except when they're optane, then I use 2.

I believe Tuxis does the same for their PBS systems. Otherwise when one disk fails, the system is instantly at risk of down-time after the next failure. Using three gives you the time to replace one while having redundancy during this process (and you get more read IOPS).

 

[LnxBil]

I will buy a second disk and setup seperate cache using special device.

I'd buy new disks (optane) for slog. You don't need a lot of space for slog. A few GB are fine, therefore a 16 or 32 GB Optane will suffice and will tremendously speed up your system on sync writes.