unraid 6.6.4 "Cache Disk free space is less than the cache floor setting"

[djcslip]

Trouble started when sabnzb couldn't unpack a file to the share. After running the fix common problems, i had the "Cache Disk free space is less than the cache floor setting"

 

The main screen show the cache is not full and the cache floor is set to 2GB. I've started the mover several times, just in case, ran all the HDD tests but nothing seems to jump out.. 

 

 

Have attached the diagnostics. Any help would be appreciated. 

tower-diagnostics-20181120-1533.zip

[itimpi]

Do you have the cache pool in the (default) BTRFS RAID1 type configuration?     The reason I ask is that in such a configuration the free space reported in the GUI is inaccurate with 2 mismatched drives.    In such a configuration the actual usable space is that of the smaller drive which may be the causes of your problem?    The way BTRFS handles redundancy is quite complicated - particularly as the number of drives goes above 2.   I do not have the URL to hand but there is a page that can calculate the usable space for different combinations of drive sizes and BTRFS settings.

[John_M]

15 minutes ago, itimpi said:

I do not have the URL to hand but there is a page that can calculate the usable space for different combinations of drive sizes and BTRFS settings.

Here: http://carfax.org.uk/btrfs-usage/

 

[djcslip]

Thank you both, i'm going to remove the smallest SSD/cache until i buy another one.  Much appreciated. @John_M  @itimpi

[John_M]

Yes, with that combination your pool size should be 120 GB (in round numbers), with half of your larger drive unused. The size is reported incorrectly, and so is the free space, but the used space is correct. So your screenshot shows you using 118 GB of your available 120 GB, leaving ~ 2 GB. Hence the warning.

 

Just shut down and physically unplug/remove the smaller SSD. You can use the cache as a degraded RAID 1 pool. When the new SSD arrives, shut down and plug it in. When you power up, assign the new SSD to the cache pool and start the array to let it rebalance.

[djcslip]

11 minutes ago, John_M said:

Yes, with that combination your pool size should be 120 GB (in round numbers), with half of your larger drive unused. The size is reported incorrectly, and so is the free space, but the used space is correct. So your screenshot shows you using 118 GB of your available 120 GB, leaving ~ 2 GB. Hence the warning.

 

Just shut down and physically unplug/remove the smaller SSD. You can use the cache as a degraded RAID 1 pool. When the new SSD arrives, shut down and plug it in. When you power up, assign the new SSD to the cache pool and start the array to let it rebalance.

doh.. busy moving all data off of the drive.. Thank you.. will do that tho !

 

[John_M]

Or just leave it as it is until the new SSD arrives. At least it's offering RAID 1 protection.