On Mon, Jan 31, 2005 at 01:11:06PM -0500, Dave Crane wrote: > I've been slowly converting my small corner of the world to JFS over the > last couple of months as I noticed significant gains (over ext3 and xfs) in > multi-user performance but something lept out at me for the firrst time last > night as I converted the root filesystem of one machine: > > ext3 pre conversion: > Filesystem Size Used Avail Use% Mounted on > /dev/md0 15G 8.1G 6.0G 58% /mnt/gentoo > > i then tarred everything up, reformatted to JFS with 'mkfs.jfs /dev/md0' and > then untarred: > Filesystem Size Used Avail Use% Mounted on > /dev/md0 15G 8.1G 6.9G 55% /mnt/gentoo > > Used space is the same, but the jfs formatted _says_ there is ~900mb more > free. > > I'm curious as to the reason, as this might be another point for me to > accelerate conversion. >
Probably it's because ext3 pre-allocates all inodes on disk whereas JFS dynamically allocates them as needed. It's not unusual to see this kind of difference on larger volumes. Sonny _______________________________________________ Jfs-discussion mailing list [email protected] http://www-124.ibm.com/developerworks/oss/mailman/listinfo/jfs-discussion
