Weird memory happenings

[birdastrompgman]

I have an 8gb Nexus 7, with >4gb free storage until recently, when I decided to keep a CWM Nandroid backup and a Titanium apps backup in external storage (I had been keeping them, and still do,  on a USB flash drive). The Nandroid backup used 1,9gb, and the apps backup used.0 6gb, leaving me with 1.8gb.
 
I wanted to make new backups, but didn't have enough storage space. Here's where the weirdness started. I found a 3gb file in /sdcard/DCIM. That didn't make sense, since I had accounted for all of my storage. Also, CWM was reportedly keeping 1.9gb of files in both its backup and blobs subdirectories. This couldn't be true, either.

I deleted the 3gb DCIM file - still 1.8gb free. I deleted the 1,9gb CWM backup - still 1.8gb free. OK,  it could be the Android unused space glitch... I rebooted - still 1.8gb free, even though I should have 3.7gb free. I booted to the bootloader recovery, and tried a Nandroid backup. It completed successfully, and left me with 1.8gb free storage.  I rebooted, cleared cache and dalvik cache - still 1.8gb free. I can live with it, but I am puzzled by the Phantom memory reports.

I later found 0.25gb cached storage hoarded by Google Chrome, which I cleared.

Thoughts and comments?

[S.Prime]

Try Folder Size Chart at Google Play,  it will show you the size of your folders for easier management.

https://play.google.com/store/apps/details?id=com.ponpocostep.foldersizechart

[JayJ]

Or DiskUsage...

We've all heard about the memory issues some have had, memory not matching up to files etc in storage under settings. I've had problems myself with the storage option in settings, I downloaded a fair few files and used Solid Explorer to move those files to my USB thumb drive but the storage in settings still says there are files still files in my downloads? I had to delete them manual through the download app, makes no sense to me that downloads that are no longer in the download folder still show up in both the downloads app and in the storage option in settings...

I have no idea what causes this, whether it's meant to be like this or what?

[birdastrompgman]

Thanks Prime and Jay,

I use SD disk storage optimizer to identify the largest directories and files for deletion or moving to my flash drive.  I'll check the apps you suggested, and use one or both of them if they offer advantages over SD disk storage optimizer.

I got to 2gb free storage space by clearing the 250MB Chrome cache.