On Tue, Jul 12, 2011 at 07:02, Theodore Tso wrote: > On Jul 11, 2011, at 10:59 PM, Mike Frysinger wrote: >> for example, some journaling file systems allow the journal to be stored >> separately. reiserfs has the "jdev=" mount option and the "--journal" fsck >> option. ext[34] have the "journal_dev=" mount option and the "-j" fsck >> option. > > At least for ext[34] and external journals, e2fsck can find the external > journal using the blkid library since the UUID of the external journal > is in the superblock. (In fact that's why the blkid library was originally > written, and why it was originally included as part of e2fsprogs.) when i read the kernel source, that seemed to be the case. but i dont think it's the case for reiserfs, and i think there's a very tiny edge case with ext[34] related to moving the journal, but probably so small we can ignore it :p. >> another example is with loop mounts that take an offset. fsck cannot operate >> on the loop source as the start of the file is not the image. it needs to >> first setup the loop with the offset, and then do the fsck on the loop point. >> /tmp/foo.img /mnt/tmp ext3 loop,offset=10000 > > How often are people using loopback mounts as a default, standard thing which > need to be mounted and checked as part of the boot sequence? I'm just > curious what the use case is for this? common enough that i got a report on it ;). it was a mount point to be checked/mounted during boot. > I suppose if this was something people really did care about, the /etc/fstab > format could be extended to add a new field at the end for fsck options --- > but it's more complexity, and could break programs try to programmatically > modify /etc/fstab. right, which is why i was thinking that parsing the fstab's options field is the lesser of two evils ... -mike -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
