I've just added 2 new drives in preparation for V6.2, one for parity and another to eventually turn my cache into a pool.

 

After the reboot, out of curiosity to see if both drives could be seen i set cache to 2 devices and from the dropdown i could see the new drives. Thinking great, i set it back to 1 device and after seeing everything show as "green ball" & "configuration valid" i started the array.

 

The problem though it seems is that the array cannot mount the existing cache drive. It's got a green ball next to it but it says it's unmountable. There is an option further down that says:

 

Unmountable disk present:

Cache • WDC_WD1003FZEX-00MK2A0_WD-WCC3F3EXPV8Y (sdc)		Format will create a file system in all Unmountable disks, discarding all data currently on those disks.
Yes I want to do this

 

Now obviously i don't want to do that.

 

I'm hoping that there is a flag that has been changed and i can on the CLI change it back, so that it believes it's still the genuine old cache. OR is there a way to mount the drive, by using that unmountable plugin to at least show the contents of the drive? I want to create a cache pool anyway, but i need some of the data off it first. I wasn't expecting that by simply changing things would make the changes permanent before i started the array.

 

thanks

if i click on the device it shows:

File system status:
Unmountable - No file system (32) 

 

File system type is set to "Auto". I know it was RS. Would changing it from auto to RS work?

 

Cache
Partition size:
976.762.552 KB (K=1024)
Partition format:
unknown

Choosing more than 1 cache slot sets cache fs to btrfs, change it back to whatever fs your cache is and it should mount again.

well i set it manually in the GUI but it's still unmountable: 

 

Partition format:
unknown
Comments:

File system status:
Unmountable - No file system (32) 
File system type:reiserfs
Array must be Stopped to change

 

Log says the same:

 

Apr 1 16:36:47 Ruby emhttp: mount error: No file system (32)

Did you start the array when you selected both cache slots?

no, definitely not.

I had same problem yesterray.You just have to check the format box in the array tab. But if you needyour data back dont do it...

no, definitely not.

what format does it give for the cache disk though?  If your test changed it maybe you need to explicitly set it back to what it should be?

well that was squeaky bum time!

 

I had to physically disconnect the drives from the server and after it booted, it recognised the cache drive 

no, definitely not.

what format does it give for the cache disk though?  If your test changed it maybe you need to explicitly set it back to what it should be?

 

well, that was the odd thin...i did explicitly set it back to reiserfs

 

Thanks for the quick replies though. Any maintenance time in my household is punishable by death!

 

I have the same problem with my nvme. that I want to use for the cache. 
Every time I format it, "unmountable - unsupported or no file system" always appears afterwards 

What can I do so that it works and I can use it as a cache?

I am very new to Unraid.

You have posted to a very old thread that has already been marked solved. Better if you start your own thread with your diagnostics.