On Wed, 2005-02-02 at 21:30 -0600, jim branagan wrote: > > > Labeling does introduce a problem: What happens if 2 partitions have the same label? Which one does mount choose? I do not know the algorithm > > > > > > It doesn't. The conflict cannot be resolved, and it will hang > Actually it says 'press any key to continue' but that just reboots > with the same problem. > > > > > In such cases , I strongly suggest changing the labels. Here I used to > > > > > have FC2 and FC3 test releases (during FC3 test) installed. > > > > > The root for FC2 was labeled / , the one for FC3 was labeled fc3/ . And > > > > > the same way for other partitions. > > > > > Now , if you need to insert another disk with the same labels , you can > > > > > always change the root=LABEL=/ part on grub to point to the right device. > > > > > This change can be done at boot time (just press "a" on grub screen) and > > > > > it probably will fix the issue, since the kernel will know exactly which > > > > > partition to use on boot time. > > > > > > > > > That would take care of getting the right root partition but what about the > > > > case where, for example, /usr was in a separate partition on each disk with > > > > the same labels? > Even if you use only hard-coded device names in /etc/fstab > and /boot/grub/grub.conf, linux will crap out and dump you into run > level 3 if there are any duplicate labels This is bull! I have often had multiple disks that are labeled the same (especially /boot and /) and as long as I have the device names in fstab and grub.conf I have never had a problem. > > > It is for that reason, that I seldom use labels. > > > A machine that has drives already labeled at boot time will give new > > > partitions created new labels. Swapping different drives in with > > > conflicting labels will always cause a problem when labels are used in > > > fstab for mounting. > > > > > > I always put the partition name in fstab instead of using labels and > > > thus do not have the conflict. > > > > > > > Swapping drives around when you have hard-coded partition names in fstab > > will also cause problems; drives can change device names and then not be > > mountable. The gist of it is that if you're adding in extra drives (and > > particularly if you're removing drives), you'd better know what you're > > doing or you could have problems. The same goes for adding and removing > > partitions, though filesystem labels are a bit more robust than > > partition names in that case. > > > > Paul. > > > Swapping drives around between PC's always requires fstab changes with > or without labels; otherwise EIDE devices never change names unless > they are physically moved to a different IDE bus or switched between > master and slave. Often, but not always. If the drive is moved from primary master in one machine to the same location in the other, no changes are required. the same applies to any ide bus location as long as it is moved to the identical location on the second machine. > I agree labels are useful for USB and Firewire drives, but they should > probably never be labeled with names like '/' and '/tmp' that are > likely to be reused on many different drives. Unfortunately the > Fedora installers (FC1, FC2 and FC3) like to create multiple > partitions with just these sorts of labels - ONCE it created a partion > labeled '/1', but most times I've ended up with a difficult to boot > machine with multiple 'LABEL=/' partitions. > In my experience, IF the previously labeled drive is in the system and you do another install it will ALWAYS label the new / as /1 ( or rather /n where n is the next unused number). The new labels are also used in fstab and grub.conf so there is no problem. If the labeled drive is not connected at the time of OS install you will wind up with duplicate labels when you connect the other drive and that always leads to boot problems unless your fstab and grub.conf have the device names > Labels would be a lot more useful if more applications displayed both > device and label (and mount point). When df displays only labels and > fdisk displays only device names, I have to look up what parameters to > give which tool to print labels for devices, and hand-map between the > two. > e2label tells you what label is on the specified partition. > It would also be very nice if I could tell fstab which partitions are > critical, and which should be ignored if not present, rather than > causing fatal errors. Currently I seem to only be able to do this if > I don't mind mounting all non-critical partitions manually after boot. AFAIK, the only fatal errors occur if / or some other mandatory partition (such as (maybe) /var or /usr) fail to mount. Otherwise it just fails to mount, posts an error in the log, and continues on using the mount point without the mounted filesystem. you could script that easily by specifying noauto for those you consider non-critical, then put mount lines for them in rc.local > -- > fedora-list mailing list > fedora-list@xxxxxxxxxx > To unsubscribe: http://www.redhat.com/mailman/listinfo/fedora-list
