[DESKTOP] ZFS HDD Sleep spin down in 18.04

[CharlieDaves]

Hi,
Just completed installing a 4xhdd raidz zfs and I am trying to work out how to "spin down" or sleep the drives when not in use
I have read this https://www.kubuntuforums.net/showth...ight=hdd+sleep
and seams relevant, but I've already setup ZFS, and I have files on there.
I did read an old (2011) blog about hdparm -S 120 command in /etc/rc.local but I don't have that in 18.04.
I have searched around the system settings, but cannot find anything specific for HDD sleep.

Any suggestions on how to sleep the whole zfs pool array?

Thanks.

[Snowhog]

Perform a Google search using this: ubuntu how to sleep zfs pool array

[oshunluvr]

Not that it's your solution, but rc.local can be created and enabled:

https://www.linuxbabe.com/linux-serv...l-with-systemd

About a third of the way down re. Ubuntu 16.04 and above.

[CharlieDaves]

Perform a Google search using this: ubuntu how to sleep zfs pool array

Thanks Snowhog. I've been 'googling' for like 15 hours already.
I did find the page about hdparm sleep https://rudd-o.com/linux-and-free-so...zfs-pool-sleep
but I don't have an /etc/rc.d/rc.local file
I have 7 /etc/rc.d0 thru to rc.d6 but no actual rc.local file

Should I ask this in a ZFS fourm ?

[CharlieDaves]

Not that it's your solution, but rc.local can be created and enabled:

https://www.linuxbabe.com/linux-serv...l-with-systemd

About a third of the way down re. Ubuntu 16.04 and above.

YIKES ! That's confusing. Is there a "Ima Dummy" version?
Thanks oshunluvr

[Snowhog]

Should I ask this in a ZFS fourm ?

That would probably be a good idea. Not that I'm trying to steer you away from here, but I don't think very many members here use ZFS, so any knowledgeable answers are more likely to come from those who use it routinely.

[oshunluvr]

That would probably be a good idea. Not that I'm trying to steer you away from here, but I don't think very many members here use ZFS, so any knowledgeable answers are more likely to come from those who use it routinely.

I totally agree. ZFS is not in the kernel and not commonly used. There are only two members here who have ever posted about ZFS to my recollection, and one of those has "retired" from most activity.

As far as enabling rc.local, it looks to me like it's installed by default, just the file doesn't exist and it's not enabled.

[FONT=monospace][COLOR=#000000]sudo systemctl status rc-local            [/COLOR]
[sudo] password for stuart:  
● rc-local.service - /etc/rc.local Compatibility
   Loaded: loaded (/lib/systemd/system/rc-local.service; static; vendor preset: enabled)
  Drop-In: /lib/systemd/system/rc-local.service.d
           └─debian.conf
   Active: inactive (dead)
     Docs: man:systemd-rc-local-generator(8)
[COLOR=#54FF54][B]stuart@office[/B][/COLOR][COLOR=#000000]:[/COLOR][COLOR=#54FFFF][B]/[/B][/COLOR][COLOR=#000000]$ [/COLOR][/FONT]

So it seems simply creating the file, making it executable, and enabling and starting the service is all that's needed.

[jlittle]

Any suggestions on how to sleep the whole zfs pool array?

Is it necessary to do it at the zfs level? Or will zfs keep waking the drives? Is the zfs pool mounted when you're not using it?

Before automating a solution with startup files, I suggest you check out commands from a konsole. I use

$ sudo hdparm -y /dev/sda
$ sudo hdparm -y /dev/sdb

to spin down sda and sdb immediately (they spin up on any access). Once you've got the commands you want, if you create /etc/rc.local and make it executable, systemd has a compatibility service that will run it.

hdparm -S 120 means a 10 minute timeout. On my system hdparm -S doesn't work, the timeout is ignored.

[CharlieDaves]

I totally agree. ZFS is not in the kernel and not commonly used. There are only two members here who have ever posted about ZFS to my recollection, and one of those has "retired" from most activity.

As far as enabling rc.local, it looks to me like it's installed by default, just the file doesn't exist and it's not enabled.

[FONT=monospace][COLOR=#000000]sudo systemctl status rc-local            [/COLOR]
[sudo] password for stuart:  
● rc-local.service - /etc/rc.local Compatibility
  Loaded: loaded (/lib/systemd/system/rc-local.service; static; vendor preset: enabled)
 Drop-In: /lib/systemd/system/rc-local.service.d
          └─debian.conf
  Active: inactive (dead)
    Docs: man:systemd-rc-local-generator(8)
[COLOR=#54FF54][B]stuart@office[/B][/COLOR][COLOR=#000000]:[/COLOR][COLOR=#54FFFF][B]/[/B][/COLOR][COLOR=#000000]$ [/COLOR][/FONT]

So it seems simply creating the file, making it executable, and enabling and starting the service is all that's needed.

I get the same result as you did.
My 'YIKES' was mainly about the content of rc.local as in services section. What is asked to put in there I have no idea what it's for. My headache has settled somewhat today so I'll giggle(C)(R) around the internet.

As for the hdparm command, it operates on individual devices, I was sort of hoping for a "pool" sleep command. I'll also try and register with a ZFS fourm or at least try and look through one, since like Linux, there's multiple flavours.
Thanks PPL

[CharlieDaves]

Another question if I may.
Is it HDD "sleep", or "spin down" or "something else" that I should be searching for?
It'll help narrow the results away from screen saver questions