Why do all disks spin up on download/install of Unraid update to flash?

[hawihoney]

On every new Unraid version that is downloaded to flash the following happens at the end:

 

- All disks spin up with some reads

- RAM cache is purged. This means a simple lookup for a file spins up all disks again if they were spinned down 15 minutes after the update (15 minutes set in options)

 

Why? I mean a new version is copied to flash. Why spinup all disks? Why purge RAM cache?

 

Thanks in advance for some information.

 

Edited November 9, 2022 by hawihoney

[BRiT]

Maybe because a 'sync" is issued that forces a flush of all data? That's about the only way *nix systems provide to ensure data is written to devices such as the removable flash drive.