Hi, I'm trying to understand why extra blocks are added when you create a file in the ext3 fs: for example, let's create a file of 1111 blocks (4096 bytes for each block) $ dd if=/dev/zero of=foo bs=4096 count=1111 the real occupation disk is then: $ du -B 4096 foo 1114 instead of 1111 So where the 3 extra blocks come from? Thanks for help! youness -- Y. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://listman.redhat.com/archives/ext3-users/attachments/20090818/da5822d2/attachment.htm>
Youness HAFFANE wrote:> > Hi, > > I'm trying to understand why extra blocks are added when you create a > file in the ext3 fs: > > for example, let's create a file of 1111 blocks (4096 bytes for each block) > > $ dd if=/dev/zero of=foo bs=4096 count=1111 > > the real occupation disk is then: > > $ du -B 4096 foo > 1114 > > instead of 1111 > > So where the 3 extra blocks come from?from the indirect blocks. This is how ext2/3 keep track of the layout of the file. see http://e2fsprogs.sourceforge.net/ext2intro.html and in particular the diagram: http://e2fsprogs.sourceforge.net/ext2-inode.gif in that paper. -Eric> Thanks for help! > > youness > > --