Bug#389881: RC-ness of this bug
On Wed, Mar 14, 2007 at 11:22:03PM -0000, peter green wrote:
> > That it's not a persistent means of identifying a filesystem.
> for most users fstab has always identified by rough position (e.g. hda=ide
> primary master), changing to a system based on partition IDs would mean a
> lot of relearning for admins (e.g. its no longer ok to backup a partition
> by dding it to another one)
> >It
> > changes if
> > you move the PCI device
> true, not that i imagine people do that much.
That doesn't make it a negligible use case.
> >, it changes if you change the SCSI/IDE bus address
> > of the drive
> the same applied in the old hd? and sd? days, drives names changing when
> you change thier IDE/SCSI ids is something admins expect and are used to.
Um. Have you ever even used SCSI?
> , it changes if the kernel changes the name of the storage
> > subsystem used to access the device (on kernel upgrades)
> true, i wish they'd stop behaving like that.
Wishes don't get you robust systems.
> >, it breaks down
> > miserably if you use fiberchannel.
> never used fiberchanel so can't comment on this.
Well, some of us have, and I don't think any admin of such systems enjoys
having to fix /etc/fstab by hand.
> to clarify my position on the overall issue
> i agree that this is too late for etch (sadly)
> by-path and by-id each have some pros and cons over each other but both
> are far better than the old scheme now that multiple controllers and usb
> devices in sd? are becoming the norm.
No, the trade-offs of by-path and by-id are *not* a clear win over the
trade-offs of the current scheme.
> by-uuid and uuid's in fstab (which seem to achive the same) is a very bad
> idea, it means that using dd to back up a partition to another one could
> result in the wrong one being mounted with potentially disasterous
> consequences.
Using dd to back up a partition to another isn't a very sensible backup
schema anyway. I think more people move PCI devices than back up systems
this way...
> It could also be a severe security issue with the help of a carefully
> crafted usb stick (especially in an environment where deployment is done
> by imaging).
Heh, that seems oddly possible, yes. I guess it's not hard to read the uuid
right out of the fstab, after all...
What does the kernel do when it finds two filesystems with colliding uuids?
Ideally, to avoid any accidents, it should rename them both. With that fix
(if indeed it needs fixing), I think all the main problems of by-uuid go
away.
--
Steve Langasek Give me a lever long enough and a Free OS
Debian Developer to set it on, and I can move the world.
vorlon@debian.org http://www.debian.org/
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