please optimise power off procedure.

[MoherPower]

Why unraid to power off needs to spin up all disk in arryay?

Why am I asking? This is problem when power fails and i need to shut down unraid running on ups. he needs to spin up all 24 disks and it taks time and POWER from ups. 

 

Second question why i need to make parity check when power fails with all array disks spin down? what can happen to data with disks powered off that needs any check? 

[Kilrah]

Properly unmounting filesystems typically requires writing things to them, regardless of the system. If the drives aren't spinning they obviously need to be started for that.

 

You'll get a parity check when the array wasn't properly stopped since for parity to be of any use all drives must be in sync and no block of any drive may change without the system knowing about it and updating the parity drive accordingly, and with an unclean shutdown the system has no way of ensuring things stayed in sync.

[itimpi]

38 minutes ago, MoherPower said:

This is problem when power fails and i need to shut down unraid running on ups. he needs to spin up all 24 disks and it taks time and POWER from ups. 

Any UPS you get for Unraid needs to be sized to be able to handle this or it is not going to be of much use.    It is also a reason why you must make sure that you do not continue running on the UPS too long after a power failure so the UPS is too depleted to handle this.    Normally one should consider initiating the power down once power has been off for more than a few minutes as by then the interruption is more than just a blip.