Distro=Deb 6

Samsung Spinpoint F3 is only recognised as 917GB. I just partitioned it and formatted it. I would normally expect it so say 1024GB (or something close, preferably larger) and after formatting have 900GB free. I almost have 900GB free, so it's not the smaller space that's the problem; it's the math.

root@localhost:/home/user# df -h /backups
Filesystem Size Used Avail Use% Mounted on
/dev/sde1 917G 200M 871G 1% /backups

917GB - 200 MB != 871 GB

Any ideas? As you can see, this will be used for backups and I want everything working as intended.

Thanks,
WT

The drive manufacturers calculate one kilobyte as 1000 byte, not 1024 byte. So a terabyte for them is 1000 x 1000 x 1000 x 1000 bytes, which are actually your 917 GB.
To your second issue, you formatted your drive with standard-parameters, which means that 5% of it are reserved for the root user. You can fix that withas root.

Hi,

I think you are running into the way things are displayed and harddisk companies that "lie".

- Seen from the hd companies: 1Mb = 1000Kb (and _not_ 1024), this will add up if you buy a 1.5Tb disk (which is not even close 1.5Tb....)

- The output of df -h is rounded, this is shown at my place: /dev/sdb3 12G 157M 11G 2% /xyz (12 - 0.157 != 11). If you want more precise numbers use df without options (bigger numbers, but precise).

Hope this helps.

Technically, its not a lie now-

http://en.wikipedia.org/wiki/Megabyte

http://en.wikipedia.org/wiki/Mebibyte

Basically, HDD manufacturers decided that they would call a MB 1 000 000bytes, not 1 048 576bytes (etc), so that advertised space looked bigger. Then when somebody took them to court for misleading labeling, they used 'kilo = 1000, therefore kilobyte = 1000 bytes' as a defense. Then they brought SI into the arguement, and so we ended up with KiB/kb, MiB/MB, etc.

So we end up with the whole kiB/kB, MiB/MB, GiB/GB confusion.

Computers use binary, why the hell use base-10 standards at all?

Hi,
I know (hence the double quotes). But in the end the consumer comes off worst (again).

Simplified: (Big) Companies => liars, Lawyers => liars and Advertisements => lies Mind the lack of double quotes

Just the opinion of a disgruntled consumer....

To elaborate on TobiSGD's post an ext2/3/4 file system by default reserves 5% for roots use but is not included in the output of the df utility.
So 917GB = 871GB + 45GB (5% value) + .2GB

Reserved space is supposed to reduce fragmentation as well as allow root to login if the file system becomes full. And as stated since this file system is just for data, reserved space can be set to zero.

Basically, the difference between the max drive space (assumes 1 partition) and 917 as is due to file system overhead.