System consumed over 300GB of disk overnight.

[jhawkinsvalrico]

This morning when I logged onto my system I was warned that the startup disk was running low on space. This is a MacBook Pro running Sierra 10.12.2 that has a 1TB SSD drive. I know that yesterday when I logged off of the system it had well over 300 GB of free space and I was not running anything that should have consumed disk of the internal drive. I do have several scheduled ChronoSync tasks that run overnight that backup data to external USB drives, but nothing else should have been running. I ran cleanmymac and searched for used disk space, but that freed up about 50GB. The system reports that 599.96 GB is being used by System.

Where do I begin looking to clean up space and to determine what consumed all of the disk space?

Thank you for any suggestions,

John

 

[Raz0rEdge]

I would recommend against using CleanMyMac (search this forums for more info)..as far as figuring out where the storage is going, grab Disk Inventory X and use it to figure out what's happening.

 

[jhawkinsvalrico]

I used Disk Inventory X and nothing obvious stands out to me so I tried DaisyDisk which I have not used before and it reports a folder in /Volumes as taking over 400 GB of space. I was under the impression that these folders were simply symlinks and all of the folders under /Volumes except the one I mentioned have 0 or almost 0 allocated space. Should folders under /Volumes actually take disk allocation?

 

[Raz0rEdge]

/Volumes is where the drives (external and internal) are mounted. So look closer at the Volumes folder to see what the space distribution is. One of the entries there will be "Macintosh HD" which is your internal storage and can be be ignored. Look for other folders in there. If you have USB drives plugged in, you should unmount them and that space should reduce..

 

[jhawkinsvalrico]

It turned out that for some reason something put a 'cloned' version of my home folder in the folder in /Volumes/John. I wasn't completely certain if the files were duplicates, but everything that I saw in Finder and using terminal led me to suspect that the folder was a duplicate. I had a backup disk from last evening's SuperDuper backup, but to be safe did a second backup to another external USB disk and then deleted the /Volumes/John folder and held my breath. Sure enough I now have all of the disk space back and all of my user files are intact. I am not certain what went haywire, but I suspect that a Chronosync task that was running encountered an issue leaving the folder 'orphaned' on the system.

 

[Raz0rEdge]

My guess is that your USB device didn't get mounted properly or unmounted from previous use and the folder still existed. However, this time the folder wasn't pointing to the external storage but rather your internal storage and thus the duplicate use of space..

Glad you it sorted out..