Questions on ZFS read/write and disk spin down

[Kivu]

Hello everyone,
i got some understanding questions on zfs read/write while idle and a possible spin down of a HDD pool.

Does ZFS itself read/write data to a tank or only if files are read/written ? (scrub?)
Will this wake up a disk and/or reset a spin down timer?

Currently i run one big HDD pool with some jails and a smb share for data on it. I think the logs of the jails prevent the HDD pool to spin down, is this plausible?

If the Jails wander to an SSD pool, the HDDs could spin down? If the jails want data from the HDD pool, the disks would have to spin up OR an L2ARC with that data must be present?

(Jails with access to the HDD pool would be plex and maybe later nextcloud.)


I want to spin down the disks to reduce heat. The data on these is rarley used by me but they still produce ~30-35°C waste heat. (Got some seagate exos dirt cheap while on sale.)

 

[SweetAndLow]

Hello everyone,
i got some understanding questions on zfs read/write while idle and a possible spin down of a HDD pool.

Does ZFS itself read/write data to a tank or only if files are read/written ? (scrub?)
Will this wake up a disk and/or reset a spin down timer?

Currently i run one big HDD pool with some jails and a smb share for data on it. I think the logs of the jails prevent the HDD pool to spin down, is this plausible?

If the Jails wander to an SSD pool, the HDDs could spin down? If the jails want data from the HDD pool, the disks would have to spin up OR an L2ARC with that data must be present?

(Jails with access to the HDD pool would be plex and maybe later nextcloud.)


I want to spin down the disks to reduce heat. The data on these is rarley used by me but they still produce ~30-35°C waste heat. (Got some seagate exos dirt cheap while on sale.)

You would probably need to move your system dataset and your jails to a different pool. That would allow your drives to spin down. It's fairly common for people to create a single disk ssd pool for their jails.

Someone will come along here and yell at you for spinning your disks down but do whatever you want it's your system.

 

[Kivu]

thank you :)
time to plan a system rebuild