This topic has been addressed a few times - a lot of help, but no definitive answer. Here’s how I did it.
I gleaned a lot of good info in the post by @gasketse in the discussion with @TonyPh12345 here “Not enough space for upgrade error” . My heartfelt thanks guys! In fact, the symptoms I experienced, and the tack I took to attempt to resolve the problem were exactly those taken by @gasketse (including the long backup and the “System Only” factory restore). So, I’ll not reproduce the symptoms here.
@TonyPh12345 was 100% correct when he deduced that “The fact that it’s not finding DataVolume means the AWK command is returning “nul,” which gets interpreted as NO space.”
The difference between the output of @gasketse’s df command and @TonyPh12345’s df command was what jogged my memory.
I executed “df -a”, in case the vanilla df itself was not working as expected, and voila - the output included /DataVolume.
I then (after making copies) modified the shell scripts /usr/local/sbin/updateFirmwareFromFile.sh and /usr/local/sbin/updateFirmwareToLatest.sh by adding the -a switch as follows:
“dfout=df | grep /DataVolume”
was changed to
“dfout=df -a | grep /DataVolume”
this modification fed the subsequent awk with the correct input allowing the script to continue.
The reason I changed both files, was that I was still undecided which method I was going to use to do the update.
As it turns out, it was too late for me to continue, so I decided to leave it till next day to continue. Lo and behold, at 05:39 the next morning the My Cloud decided to autoupdate anyway. The autoupdate feature had never worked for me and I was about two years behind in upgrades - due to the disk space problem.
All seems good now - but slow because system is re-scanning…
Oh, yes, and my df command now, after the update, works the way TonyPH’s did - no more need for the -a. I also suspect that my original problem occurred because of an apt-get - I’m sure WD could control that better. Anyhow, lesson learned and I’m back to standard. I ran the apt-get because of issues I was having with failing TimeMachine backups. Now I back up to a MyPassport - crude, I know…
