emmanuel_uk Posted February 12, 2007 Report Share Posted February 12, 2007 (edited) Hello, In short the rsync backup of /home/users1 into /home2/users1 are not the same size using du -c --blocksize=1 (no linux pc at hand, but from memory I tried lots of du flags) I decided at last to learn rsync to backup /home/user1 which is ext3 to another IDE HD using as root rsync --delete --archive (and some other flags) into an empty destination directory, under mdv 2007 The directory /home/users1 contains about 3.7 Gb and is about 20 Mb bigger than the backup /home2/users1 (both using ext3) Files are all sort: pictures, tar.gz, lots of rpm, pdf, html, lots of hidden directories. most files by users1, some by root. Very few or no links (hardlinks or not) I did a reverser rsync from home2 into home using --dry-run, and it looks ok. SO, why is there a size discrepancy? Is this to do with sparcity of files? Is this to do with journaling? Do I need to run e2fsck? Have I got space taken by dead files? I am using badly du? (I used konqueror directories information size, there is also a size difference) I have read man pages for rsync and du, but I must have missed something Have you got any pointers or suggestion of what to do (apart from using cp -R, or rsync --checksum which I may try...) Thanks Edited February 12, 2007 by emmanuel_uk Quote Link to comment Share on other sites More sharing options...
ianw1974 Posted February 12, 2007 Report Share Posted February 12, 2007 Is there any particular reason why you're using rsync to keep the partitions in sync? There's a much easier way creating a Raid 1 array for both these partitions, and then letting it manage itself. I've done this, here is my link on converting existing partitions to Raid 1 arrays: http://linuxsolutions.org/index.php?option...5&Itemid=26 I've moved stuff from one disk to another in this howto, and found size discrepancies, but it wasn't anything to worry about. Maybe your rsync is similar in terms of results. I also was using du to check it all. Quote Link to comment Share on other sites More sharing options...
emmanuel_uk Posted February 12, 2007 Author Report Share Posted February 12, 2007 tahnks Ianw1974 Is there any particular reason why you're using rsync to keep the partitions in sync? Well, had enough of cp, plus cp builds up file like firefox cache each time I backup, also rsync faster, also the synchronisation is nice. Excluding files or list is nearly impossible with cp -R. Wanted the delete function on the target directory Anyhow wanted to learn rsync Always heard (apart from raid1) that it was a good backup method. (have played with dd and cp for backup purposes, so now rsync) My mobo is raid 1 capable, but with the partition scheme I have it is too late for a raid 1. I played with raid 0 at first, but had 1 or 2 loss of data (as expected), due to HD leaving the mount point randomly only three times over ~ 6 mths, so did not want to do raid 1 anyway Also raid 1 really decrease amount of space available on a non-server home system, sparcity is high, so no point of doing a raid1. I've moved stuff from one disk to another in this howto, and found size discrepancies, but it wasn't anything to worry about Interesting you noticed this as well Well I am worried... am sure it is something I do not understand not an OS problem. Do not like this discrepancy. I really wonder if it an inode story or journal What I am going to do is rsync into /home2/user1 then cp -R into /home2/user1_bis compare size Most likely will be the same for /home2/user1 and /home2/user1_bis but 20 Mo less than /home/user1 then probably investigate a bash way to compare two du outputs directory by directory Quote Link to comment Share on other sites More sharing options...
ianw1974 Posted February 12, 2007 Report Share Posted February 12, 2007 Probably most likely something to do with the filesystem and mount options. Quote Link to comment Share on other sites More sharing options...
emmanuel_uk Posted February 12, 2007 Author Report Share Posted February 12, 2007 rsync --recursive --archive --verbose --update --delete --stats --human-readable /home/ /home2/ Well, not using du correctly. The expected answer is when using flag b (I must say I know a bit about filesystem, but flag b is counterintuive if not thinking hard) compare du -cks /home/user1/.Skype; du -cks /home2/user1/.Skype 1656 /home/user1/.Skype 1656 total 1664 /home2/user1/.Skype 1664 total to du -bcks /home/user1/.Skype; du -bcks /home2/user1/.Skype 1525 /home/user1/.Skype 1525 total 1525 /home2/user1/.Skype 1525 total --apparent-size or -b print apparent sizes, rather than disk usage; although the apparent size is usually smaller, it may be larger due to holes in (‘sparse') files, internal fragmentation, indirect blocks, and the like I still have discrepancies on the total of all the directories. To do with one symlink I think Quote Link to comment Share on other sites More sharing options...
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