The typical number of reserved blocks for ext3 is 5%. So that much space is actually reserved. You can change that limit when formatting the ext3 file system.
mke2fs -j -m 0 Amitay. On Thu, 2003-11-20 at 16:10, Keith Fernandez wrote: > > I believe this must be the size that is taken up by the filesystem > > data itself ... > > Thanks Sameer, > Just one more question, Would there be such a huge difference. > 33k is what the file system is using, 33 MB is what showing and 400 MB Is the > difference between total size and available. > > More importantly is there any way to correct this. > Can I get usage stats of my hdd which are much more reliable. > I did try "sync" but that did not seem to help. > > Regards, > Keith > > > On Wed, Nov 19, 2003 at 08:09:18PM +0530, Keith Fernandez wrote: > > > Filesystem Size Used Avail Use% Mounted on > > > /dev/hdb1 7.7G 33M 7.3G 1% /vol2 > > > > > > THe size of the disk is 7.7 GB and it says available is 7.3 GB > > > that means 400 MB is used, it however reports 33M is used, although > > > the HDD is empty. > > > > Two possible reasons - some space is actually used up in the > > filesystem data, such as inode tables and superblock information in > > case of extx. Also, the values in Gigs and Megs will have problems > > rounding up ... try comparing the actual bytes used. > > > > > And "du -sh /vol2" gives me > > > > > > 37kB /vol2 > > > > > > There is nothing on the partition /vol2. What could be the reason for > > > this... > > > > I believe this must be the size that is taken up by the filesystem > > data itself ... > > > > > "Deleted files/open files still held open are reflected in df but not > > > du." > > > > Thats true ... typical examples are the files in /var/log ... the > > actual space taken up on the disk at a given time is different from > > what the filesystem thinks is the size of the file ... df and du work > > by looking at different sources for their information, hence the > > discrepancy. > > > > du will tell you exactly how many bites are taken up by the file. But > > df will simply ask the filesystem to see how many blocks are allocated > > to the same file. Thus if you create a file containing a single byte, > > du will say "one byte" but df will say one block, that is 512 or 1024 > > bytes in most cases! > > > > Since very few files are exact multiples of the block size, a little > > space is wasted in every file - that's called internal fragmentation, > > I think. Hence df will report more than the actual physical size - it > > will show the amount of space that has been "allocated" to the file. > > > > DISCLAIMER: These are my conjectures based on a little familiarity > > with filesystems, somebody please correct me if I am wrong! > > > > Sameer. > > -- > > Research Scholar, KReSIT, IIT Bombay > > http://www.it.iitb.ac.in/~sameerds/ > > -- > âI asked for strength and God gave me difficulties to make me strong. > I asked for Wisdom... and God gave me problems to solve. > I received nothing I wanted... But I received everything I needed." Amitay. -- God gives the nuts, but he does not crack them. - Old Proverb -- http://mm.ilug-bom.org.in/mailman/listinfo/linuxers
