File Size on Disk Error?

phlaaj · 2011-03-22 19:19:46

Hi all,

Not an urgent issue I don't think, but I noticed when I looked at the file properties of various folders in my home directory that the file Size on Disk is typically several times larger than the Total Size of Files reported. For example, my documents folder Total Size of Files is 16.8 GB, while the Size on Disk is reported as 134.6 GB. My music folder has a Total Size of Files of 42.3 GB, while its Size on Disk is 338.9 GB. As my actual total disk size is only 160 GB, I don't think the Size on Disk numbers given are accurate. Also, I just noticed that the Size on Disk/Total Size of Files ratio is roughly the same for both of the above folders: = 8.012

I just ran fsck and it didn't detect anything. I am running pcmanfm 0.9.8-5, and my /home filesystem is ext3. Does anyone know what may be causing the above error, what the effects of the error would be, what systems/processes it may be affecting, and/or how to fix it?

lagagnon · 2011-03-22 20:06:03

I believe pcmanfm is incorrectly reporting the "Size on Disk" whatever that is! There are other posts on the Internet to this regard. I would ignore that number, whereas the "file size" does seem to be reported correctly. I would use "du" from the command line if you wish to know how much space your directories are taking.

lives2evil · 2011-03-22 20:13:01

Interesting!!!! I have this problem also.
Never notice it until now. True enough, the size is 8 times higher and it's persist in ext4 and ntfs.
And here come the interesting part:
Nautilus, Thunar and of course Dolphin have no such error. Why?
Simple, they do not have such thing as "Size on disk".
And the ntfs I tested is newly formated too.

So conclusion: it's pcmanfm problem and solusion: report it please

phlaaj · 2011-03-24 14:16:18

Thanks a lot - if this is an old and well-known issue with pcmanfm, I will assume the devs are aware.

CaCO3 · 2011-08-30 02:25:36

I have the same curiosity But I don't think it is a error. (second thoughts below)

I have exactly the same file on my usb drive and on the hard drive which is formatted with an EXT3 partition. I got the following results.
Fat32 file system ( on my usb drive)
File size: 105.9 MB
Size on disk: 847.3 MB (847,347,712 bytes)

EXT3 file system :
File size: 105.9 MB (105,918,114 bytes)
Size on disk: 848.2 MB (848,232,448 bytes)

As far as my knowledge on this goes it has something to do with the sectors on the hard drive. For example if you have 1.5 litres of water and a 2 litre container to put it in, the total space that the water will take up in the end will the 2 litres.

I have also noticed that EXT2 file system will give you more file space than a EXT3 file system. Something to do with the fact that ext3 is a journaling file system?

Another thing I wanted to know in pacmanfm: What does the 'free space' in the bottom right hand corner represent? So I copied the same file mentioned above on to the hard drive again which has a current free space of 290GB. If it represents the free file space it should still stay around 290 Gb. If it Represents the 'size on disk space then it should say that the remaining space is about 289GB. I copied three of that same file over to the hard drive and it gave the conclusive result of 289.7Gb. So it represents the free 'file space'.
Now that I know that it creates a new question: How much physical space does a hard drive really have on it? Does my 320gb hard drive really have 320gb of space? Or does the manufacturer create a 2563GB hard drive so that it will equal about 320GB after formatting ( as the ratio of 'size on disk' and 'file size equals to about 8) ?

Or is pacmanfm just insane?

It seems that I have only added to the confusion of this thing.

Last edited by CaCO3 (2011-08-30 02:34:58)

B-Con · 2011-10-26 04:09:25

FWIW, I found the problem. (This bug is still persistent in v0.9.9.)

My (new) PCManFM bug report is here: http://sourceforge.net/tracker/index.ph … tid=801864
I submitted a potential patch here: http://sourceforge.net/tracker/?func=de … tid=801866

Bottom line is that the file's block size and block count data from the file's inode wasn't being interpreted and used properly. The bug is in PCManFM, not any dependent libraries. Details are in the bug report.

Since PCManFM is highly used by the Arch community, I figured I should post an update here so that there's some record of it in our community. Hopefully this gets addressed by the developer(s) relatively soon. :-)

Last edited by B-Con (2011-10-26 04:10:45)

Arch Linux

#1 2011-03-22 19:19:46

File Size on Disk Error?

#2 2011-03-22 20:06:03

Re: File Size on Disk Error?

#3 2011-03-22 20:13:01

Re: File Size on Disk Error?

#4 2011-03-24 14:16:18

Re: File Size on Disk Error?

#5 2011-08-30 02:25:36

Re: File Size on Disk Error?

#6 2011-10-26 04:09:25

Re: File Size on Disk Error?

Board footer