what't that ext3/ext4 difference?
time and performance :)
+ only used inodes are checked during fsck = time-saving
it's not quite common - but you really want to use ext4 for /var/vmail
having huge filesystems of xxxTB by using ext4 only really "in use" inodes are checked - so your fsck will take less time to finish
create the filesystem
please replace /dev/null with "your" disc
mkfs.ext4 -T news -m 1 -L mailstore /dev/null
+use "news" as type (more inodes possible) - mails are usually less than 1mb
+ volume-label is "mailstore"
tune4fs -o journal_data /dev/null
+ we want it journaled
/dev/null /var/vmail ext4 noatime,data=journal,journal_checksum 0 2