Re: [util-linux] Re: magic device renumbering was -- Re: Linux 2.4.2ac20

[Mikael Pettersson <mikpe@csd.uu.se>]

Andreas Dilger writes:
 > Andries writes:
 > > > I've implemented a patch for util-linux-2.11a
 > > > which adds LABEL support to mkswap(8) and swapon/swapoff(8).
 > > 
 > > But I would prefer a somewhat more ambitious approach.
 > > 
 > > My first thought was: why label individual swap partitions?
 > > I almost never want to distinguish swap partitions, and just do
 > > "swapon -a". In case one wants to guard against changing device names,
 > > why not add an option -A so that "swapon -A" does swapon on each
 > > partition with a swap signature?
 > > 
 > > However, that would greatly increase the risk that exists already
 > > today: someone has a swap partition, and does mkfs.foo, and
 > > it so happens that foofs does not use the sector with the swapsignature.
 > > Now this foofs partition has a swap signature, but we would be very
 > > unhappy if it were used as swap space.
 > 
 > I think the LABEL is a good intermediate step for people not using LVM.
 > It basically allows your /etc/fstab to not have _any_ device names in it.

Exactly. IMO, it doesn't really help having LABEL= on your ext2 partitions
in /etc/fstab if you cannot also do the same on swap partitions.
My LABEL= patch for mkswap/swapon may not be as sexy as a brand new partition
table format [which arguably is the better solution in the long run], but it
does provide a useful improvement NOW with minimal implementation cost and full
compatibility with existing 2.2/2.4 kernels.

 > I'm not sure I would be happy with auto-mounting swap partitions,
 > especially because this would overwrite any data in the partition.  Bad.

Me too. I can easily add Andries' "swapon -A" to my patch, but I really
don't think that semantics should be the default.

Cheers,

/Mikael