Storage Usage Mistery

[tarum]

hey guys. i`m new to NAS and synology and i`m a little lost solving my problem and after looking a lot I still can`t find anywhere some explanation to my storage consumation, so i hope you guys could help me.

i have a ds213+ runing DSM4.3 with two disk in Synology Hybrid Raid having a total space of 2.68 TB. The total used space is 1.8 TB, but i don`t know where are all theses files. We are currently 5 users and almost nobody is still using. I even check the quota of each one and the total usage of the 5 are about 580 GB. We have some share folders but almost all are empty so far. There are only 2 time capsule activate currently with a total of 300 GB of space (checking the folders).

I`m trying to breakdown this data but can`t find anyplace where it can give me this information. Anyone have any idea how I can check where and what are all those data??

we almost didn`t start using, but there are some backups and other datas, so I really didn`t want to make a clean start.

 

[Nerre]

The "used space" on a drive is generally always larger than the sum of file sizes.

How big the difference is depends a bit on what file system you use.

For example most file systems use some kind of blocks to store data in. This means each file will waste on average one half block. If the blocks are 4 kB each file will on average waste 2kB.

In some file systems (most notably FAT) a subdirectory is allocated as a file, and grows as needed. However does not shrink as needed. So if you have had a lot of files in a subdirectory and delete them the space will still be considered "not free" since it is occupied by the empty "container file". Defragmentation in Windows has the option to "compress directories".

I'm not sure if this still applies to FAT32, but the "block" thing applies to most file systems (but the blocks have different names).

Also some space on the disk is occupied by the file system itself (the index part that makes it possible to locate files without having to scan the whole disk for every file).