HDD power saving/management in ZFS

[takkischitt]

When you have 2 HDD's in stripe using ZFS (see my setup in sig below), can you use 'HDD Standby' or 'Advanced Power Management'?

 

[cyberjock]

Any reason you think I stripe wouldn't work when a mirror, RAIDZx, or single disk would? I'm not seeing why your pool architecture would have any affect on hdd standby or APM setting...

 

[takkischitt]

I was just wondering if one HDD could go into standby but the other didn't and if it could, would that cause issues due to the HDD's being 'joined'?

Am I using the correct terminology when I describe my two 500GB HDD's joined together to be 1TB as being in stripe?

 

[cyberjock]

They'll both be woken up by virtually any read or write to the pool. Regardless of your pool design, you can usually expect that any read or write to the pool will wake up the entire pool.

Yes, a stripe is what you have.

 

[takkischitt]

The system is running in an office which operates roughly 9am to 5pm. It is used for backups which are done throughout the day, but after 6pm there is probably no usgae of the FreeNAS system at all (all computers switched off). What would you recommend for the 'HDD Standby' or 'Advanced Power Management' settings? I was thinking...

• 30 min HDD Standby
• Level 64 Advanced Power Management

 

[cyberjock]

I don't recommend sleeping disks at all. Sleeping disks requires no activity on the pool(which often doesn't happen when people think it would) and the act of spinning up the disks excessively seems to shorten their lifespan.

 

[takkischitt]

So just leave the settings as follows...

HDD Standby - Always On
Advanced Power Management - Disabled

 

[Yatti420]

Really depends on use.. I don't think you have any redundancy with 2 drives striped.. If they get 1 daily backup and never do anything else I'd consider spinning it down..