SSD suitable as L2ARC like for ceph storage?

[fips]

Hi,

to pick the right SSD I would like to go for the same specification like for my ceph storages.
Here is a link here you can find out if your SSD is suitable for as a ceph journal device.

https://www.sebastien-han.fr/blog/2...-if-your-ssd-is-suitable-as-a-journal-device/

Does it count for ZFS too??

 

[Stux]

An L2ARC SSD does not need to be journal grade. L2ARC is (currently) re-initialized on restart, ergo, it does not matter if syncs are flushed correctly.

A SLOG is an entirely different thing.

 

[Arwen]

An L2ARC SSD does not need to be journal grade. L2ARC is (currently) re-initialized on restart, ergo, it does not matter if syncs are flushed correctly.

A SLOG is an entirely different thing.

Actually, work is being done to support a persistent L2ARC. Here is the reference;

https://wiki.illumos.org/display/illumos/Persistent+L2ARC

Don't know if / when it will show up in the general ZFS releases.

 

[Stux]

Actually, work is being done to support a persistent L2ARC. Here is the reference;

https://wiki.illumos.org/display/illumos/Persistent+L2ARC

Don't know if / when it will show up in the general ZFS releases.

"If for whatever reason this fails (i.e. L2ARC device died, or retrieved data is corrupt), the read is re-issued to the main pool."

Point is that even if it is Persistent, you still don't need a journal grade SSD as ZFS will take care of it, as its only ever a cache of pool data, its integrity does not matter.

 

[Arwen]

@Stux,
Yes. I did not mean to imply that a L2ARC device needed power loss protection.
Just clarifying that persistent L2ARC may be an available feature in the future.

 

[Stux]

@Stux,
Yes. I did not mean to imply that a L2ARC device needed power loss protection.
Just clarifying that persistent L2ARC may be an available feature in the future.

Thanks. I was aware of persistent L2ARC, but I enjoyed the read :)