Reminder: Linux disk device names are not persistent or predictable

Repeat with me:

Linux disk device names are not persistent or predictable

These two Red Hat KCS notes provide lots of information:

... but TLDR: disk under /dev/sd* and /dev/vd* are not persistent nor guaranteed to be predictable in any newer kernel version.

DO:

  • Rely on filesystem's UUID for /etc/fstab mount settings (see blkid)
  • Use persistent names like: DM multipath, LVM device names, kernel persistent names (/dev/disk-by-*), or udev-assigned custom names.

DO NOT:

  • Try to create names in the /dev/sd* namespace.
  • Try to ensure /dev/sd* are consisent across machines, or even reboots of the same machine. They won't be.
  • Try to implement kernel or module options, they will fail.

If you find any software that tries to impose any logic into the /dev/sd* namespace, that software is buggy and must be rewritten accordingly.

Happy hacking!