Hi All,

 

Running unraid version 6.8.3 -

 

I have a single btrfs 1TB SSD which is showing its age having written well over 300TB's in its 5yrs 9months of power on.

It holds around 380 gb data from dockers and vm's and as it is a single drive I have decided it should be retired to less important duties!

 

Looking at the following -

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?tab=comments#comment-480419

 

I proceeded to stop the array, insert the new SSD cache drive and restart the array, Unraid offered me the option to format the new cache drive which I have done.

 

I was expecting a btrfs device swap to begin but that has not happened so now Im a little nervous as to the next steps.

 

The old cache drive was showing as an unassigned device with the new cache drive just sitting pretty empty.

Both the docker service and the vm service are currently switched off in settings.

 

 

Being a little nervous about loosing the existing cache data I have stopped the array and reselcted the old cache drive, however I now have a red warning telling me that "All existing data on this device will be OVERWRITTEN when array is Started"

 

 

Can somebody please confirm or point me towards the correct and current process from here?

I really do not want to overwrite the old cache data.

 

Huge Thanks dgs2001

Edited December 3, 20205 yr by dgs2001
spelling

4 minutes ago, dgs2001 said:

Unraid offered me the option to format the new cache drive which I have done.

Something wasn't done correctly, please post diags.

3 minutes ago, JorgeB said:

Something wasn't done correctly, please post diags.

JorgeB,

 

Thanks diags attached.

 

Currently I have the old cache (Samsung_SSD_850_EVO_1TB_S21DNXAG611036H) mounted and am manually copying the contents.

Unraid is currently using the new SSD cache drive (ZA1920NM10001_HKS02CWE)

 

Your help is appreciated, Im sure its something simple but I dont want to destroy the existing cache data

tower-diagnostics-20201203-1218.zip

The FAQ mentions in bold that:

Quote

You can directly replace/upgrade a single btrfs cache device but the cache needs to be defined as a pool, you can still have a single-device "pool" if the number of defined cache slots >= 2

You only had one cache slot.

 

Unassign current cache, start the array, stop the array, set cache slots to 2, assign old cache (there can't be an "all data on this device will be deleted" warning), start array, check old cache is mounting correctly, stop array, now you can replace.

 

 

Also don't forget to unmount old cache from UD before re-assigning.

JorgeB,

 

Thank you for your help. Seems so simple now, I thought I had probably gone wrong somewhere!

 

Having gone wrong my second mistake was to fail to unassign the current cache with a start array, stop array cycle before attempting to re-assign the old cache.

For anybody reading this in future suffering a similar faux pas, I was unable to select 2 cache drives until I had succesfully re-assigned 1 cache drive then stoped the array again at this point I was able to select 2 for the number of cache drives.

 

All is now as expected with a btrfs operation underway.