From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eriberto Subject: Re: Space lost? Date: Sat, 07 Jan 2006 11:23:59 -0200 Message-ID: <43BFC0EF.9080901@eriberto.pro.br> References: <43BF4857.8070901@eriberto.pro.br> <3405.66.131.16.74.1136610974.squirrel@x2a.org> <43BF92DB.5010409@slaphack.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <43BF92DB.5010409@slaphack.com> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: reiserfs-list@namesys.com Hello David. Thanks for your reply! David Masover escreveu: > In other words, those 604 KB are things like the magic number, so > >utilities like "file" can guess what FS it is, or what type of file if >it's an image, and mostly things like the journal and the amount of >space it takes to represent one empty folder. > > Ok. I am intrigued with a fact: the ext3 uses 14 MB (14.935 KB) when formatting the same partition. Is this a magic number too? It is very large! As the Reiser4, ext3 uses 5% of space to administration by super user. However this 5% are inserted in the patition use (the 14 MB as 604 KB are out of patition). For that I know, the journal is in the partition too. When I format a partition, immediately after the df command shows a amount used. This is the journal. Or not? >And btw, if you put exactly 100KB on your disk, split into 1KB files, >you're probably going to notice your disk usage going up by more than >exactly 100KB. How much it goes up by is going to be roughly equivalent >to how much space it takes to store the name of each 1KB file. > >Here's another interesting experiment: Take a directory tree of lots of >small files. Gentoo's /usr/portage is a good example. Copy it to ext3, >XFS, reiserfs, and Reiser4, then run "du -s" on each copy. I can almost >guarentee that Reiser4's is going to be significantly smaller, enough to >show up on even "du -sh". Smaller by tens of megabytes, at least. > > I heard to say that Reiser adapt the size of the block to the size of each file. Is true this? >So you really shouldn't complain about your lost 604 KB. > > > I need to understand how this works to be able to explain to my pupils. Thanks in advance!