Quoting Paul E Condon (pecon...@mesanetworks.net): > You can also use disk LABEL=. As implemented, the LABEL is actually > applied to individual partition. As long as every partition has a > different LABEL values there is no ambiguity. You only need to have > unique values for partitions that you feel you will be mounting and > umounting. Partitions with no LABEL value set never get compared by > LABEL value.
That may be a problem for anyone using wheezy as it only appears to have UUIDs and LABELs, and not PARTUUIDs and PARTLABELs available. As discussed, only PARTXXXs are persistent. (If ever I let the Debian installer loose on my labelled swap partition, I have to relabel it afterwards.) > The system has always insisted on setting a unique UUID > value on every partition. Its done that way because of a design > decision of Debian developers. The world has decided that, not just DDs. > But it has a tiny flaw that you can > avoid by using LABEL values, which YOU can be sure are unique because > you didn't do repeats, whereas UUIDs are randomly generated and there > is a tiny, but non-zero chance of repeats for UUIDs. Oh, please. "Assuming uniform probability for simplicity, the probability of one duplicate would be about 50% if every person on earth as of 2014 owned 600 million GUIDs." (Wikipedia) What if you're running a disk farm of several thousand drives? No, LABELs don't scale well. > If I read your message above, you are having trouble understanding how > to use the UUID/PARTUUID system for identifying partitions on disks. > I suggest that you don't need to use it, and if you don't use it you > don't need to understand it. That's ok until Debian does something behind your back that catches you out. For example, GRUB uses UUIDs, whereas I prefer LABELs. But I have to understand what GRUB/Debian Installer/Upgrade is doing so I can mitigate the effects. > I was once troubled by a similar situation when Debian first started to > use UUID, until I realized that for some disks, I had no intention > of ever changing the partion structure that was put there initially. Hm. Never say never. > For disks that I did have some special use and some ideas about how > that special use might change in the future, I put LABEL=... on their > partitions and used LABEL= paradigm to identify the partitions. This > is what I do with all my external drives. And I put sticker on the > outside of the drive enclosure with the LABEL= value written with a > ball point pen on it. It is my personal responsibility to myself that > I never put the same LABEL= value on two different disks. I agree. All my disks, internal and external are named and labelled just so. But I have so few, and all in different rĂ´les. If I had lots, I wouldn't bother. > You can even > put a LABEL= value on the root system disk that is always /dev/sda1 > during installation. I suggest that you use LABEL=sda1. Bad idea. The names should not be loaded with extra meaning. My partition labelling *is* overloaded: mama01, 02 ... but I'm prepared to live with the necessary constraints: creating them in the correct order, and not resizing/creating new partitions afterwards unless I make a clean sweep of it. What if you/(s)he were to take a disk labelled sda1 and put it in another computer to clone/recover/whatever it. Now it sits in a box where there's a /dev/sda1 and a /dev/sdb1 but the latter is called sda1. A recipe for disaster. > As I see it, the only benefit that you the user get from using the > UUID/PARTUUID system is that if some Linux user is browsing through > the internals of what is written on your disk, he may wonder where > you got the software to do that and treat you with a little more > respect. Let me assure you, you are not Rodney Dangerfield Eh? Cheers, David. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/20150401211903.gb21...@alum.home