Quoting Craig Sanders (cas@taz.net.au):
Fortunately, you can assign labels to partitions or filesystems when you create them (or add one later), and these are much easier to read and use.
Care to learn hour to make a Linux system go belly-up in a way field-proven to puzzle Linux experts for days? Simple: Accidentidally connect two disks with the same assigned disk label, and then attempt to boot it. This was posted a decade or so ago to the Silicon Valley Linux User Group by one of the leading experts who'd just solved the problem after being stumped by it for days. (I can't remember the exact signs of distress the system gave, if any, before falling over.) I didn't try to replicate the problem. I merely made a mental note that, IMO, this was an adequate reason to eschew disk labels completely: one fewer bizarre failure mode to watch out for. I always imagined that someone was handed an account of that shambles and told 'Please design for the Linux community a disc identifier system that avoids all such failure modes through the expedient of using an absolutely guaranteed, totally unique identifier. Feel free to sacrifice all other objectives such as ergonomics and human-compatibility. Just be absolutely certain the identifiers are unique, at any cost.' Eh volia! UUIDs.
changes in the order that kernel modules are loaded
FWIW, I generally compile my own kernel, and critical drivers get compiled inline. Never seen the above problem, and my kernel practices may help somewhat.
minor variations in the timing of exactly when drives are detected by the BIOS or kernel (e.g. sometimes a disk might take a few milliseconds longer to spin up on a cold boot)
Still have never seen that on my systems. Still waiting, since 1992. It may help that I favour relatively simple and homogeneous hardware.
BTW, modern linux systems populate a directory called /dev/disk/by-id/ with symlinks to the actual device names.
I look forward eventually to losing udev on server systems and migrating to mdev, which among other things will lose the above. ;->
If you're using LVM with RAID-1, you don't need mdadm - LVM can do RAID-1 itself.
But mdadm / the Linux md driver are superb at doing Linux software RAID, so IMO should be favoured as best of breed.