ZIL / L2ARC Question

[gregg098]

I have an extra 120 GB SSD laying around and I would like to set it up for ZIL and L2ARC, but want to clarify something first.
In my setup, I have two ZFS pools. They are:

• - 2x 480 GB SSDs in mirror (rpool) - Created during Proxmox install
  • This pool has Proxmox and all containers/VMs on it
  • Lots of disk activity since it has the host OS and all of the VMs/containers
• - 2x 8TB HGST Diskstars in mirror (datapool) - Created after install
  • This pool is nothing but data (movies, music, and also Proxmox backups from this machine and another NUC I have running)
  • Some disk activity. Mainly adding new movies and scheduled backups. Mainly large files.

If I add a 120 GB SSD for ZIL and L2ARC, I understand I should make 2 partitions. My thoughts were 15GB for the ZIL partition and and the rest for L2ARC. My system has 24 GB of RAM.

Question: Does the ZIL and L2ARC work for the entire system or just one pool? If only one pool, which pool should I set this up on? I"m guessing rpool?

Second Question: I'm not heavy in parted or gdisk. Can someone give me some example commands to setup the two partitions I want? I found a few threads and references, but just want to be sure I do it right.

Thanks.

 

[Whatever]

1) ZIL and L2ARC devs link to given pool only and cannot be shared
2) In case you have enterprise grade SSDs (2x480) like Intel 35xx/37xx series I would recommend to use 120GB SSD as L2ARC only

 

[gregg098]

1) ZIL and L2ARC devs link to given pool only and cannot be shared
2) In case you have enterprise grade SSDs (2x480) like Intel 35xx/37xx series I would recommend to use 120GB SSD as L2ARC only

They are just run of the mill SSDs. So should I use the 120GB SSD for L2ARC on this pool or the 8TB mirrored hard drive pool? Whats the pro/con of each?

Thanks.

 

[6uellerbpanda]

Why do you need a slog ?? You have a lot of sync writes on your datapool??

Do you even need a l2arc ??? Check https://forum.proxmox.com/threads/zfs-worth-it-tuning-tips.45262/page-2#post-217209

 

[gregg098]

Probably not after reading this. I got the impression from everything else I read that this would help with overall performance in most situations. Thanks.