I'm not entirely sure (haven't tested more than once) but it seems that my array has started spinning up when copying files to it - even though there is plenty of space on the cache pool (and share copied to is set up to use cache)

 

File does get copied to cache. Is this something about folder caching that could have changed?

 

Cheers,

 

T.

UnRaid does have to check the disks first to see if the file already exists on any of the disks used by the share.    It is only after that check that unRAID can decide the file should be copied to the cache.

UnRaid does have to check the disks first to see if the file already exists on any of the disks used by the share.    It is only after that check that unRAID can decide the file should be copied to the cache.

 

 

Is that true?  If so, it would explain why my drives don't spin down as much as I would like even though I use the cache for most shares.

 

 

But doesn't that add delay if unraid has to wait until drives are spun up before writing to cache? Is there a way around this because the reason I use my cache is more for silence than speed.

There is the Dynamix Cache Directories plugin which attempts to keep directory information in memory so that it does not have to re-read it from the data disks, thus reducing the need to spin up disks in such cases.

UnRaid does have to check the disks first to see if the file already exists on any of the disks used by the share.    It is only after that check that unRAID can decide the file should be copied to the cache.

 

 

Is that true?  If so, it would explain why my drives don't spin down as much as I would like even though I use the cache for most shares.

 

 

But doesn't that add delay if unraid has to wait until drives are spun up before writing to cache? Is there a way around this because the reason I use my cache is more for silence than speed.

since the only requirement to spin up the drives in such a scenario is to check the directory entries then you can avoid the need to spin up the drives by installing the Dynamix Cache Directories plugin (assuming you are not too tight on RAM to cache the entries) so that the directory entries can be checked without spinning up the drive.  That way the drive only needs spinning up if unRAID actually selects the drive as a target for the file.

 

A point to note is that if a file already exists then unRAID will not use the cache if you want to amend/overwrite the file.  In such cases it writes directly to the current location.  If you first delete and then recreate the file it will be written to cache but the drive will have been spun up to delete the directory entry that held the original file.  Not sure in such a case if the cache directories plugin makes this asynchronous to writing the new file to the cache drive.