5N Shares - Disk Full Error

My Drobo 5N is fully populated with 4TB mechanisms (20 TB total), and only two blue capacity lights are illuminated.

There are 6 Shares dedicated as TimeMachine backup partitions.

Some of my users are experiencing TimeMachine backup errors:

[color=#FF0000]The backup disk “Drobo 5N” is full[/color]

This cannot possibly be true.

Is there a way to expand or reallocate the share size partitions? It appears I configured the device wrong, and it is reporting full when only 20% of the available capacity is being utilized.

Also, why isn’t TimeMachine simply deleting older backups?

One theory I have is that the users impacted are running Parallels/Windows 7, and any small change in a Windows document causes the Mac to see the entire Parallels partition to have changed, thus invoking multi-gigabyte backups on a daily or even hourly basis.

hi, the part about parrells is definitely worth investigating further, because it may be a case where each instance of windows is treated as a single large file and whenever it is updated, it might be doing version control, and with each file being large, it will easily gobble up all the space.

can i check how many blue leds yoru drobo is showing lit (or used space and free space from dashboard), and is time machine itself limited to a certain total size that it can eat up on the drobo?