[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Persistent device names



To discuss this subject, I've still wanted to set up a discussion with at 
least Marco, you, Joey and Colin, but for different reasons have not 
gotten around to that.

As I'll be on holiday for a few weeks after Debconf, let me at least list 
the issues that I've had in mind and that should be considered when 
implementing changes for persistent device naming.
Please add to the list and comment.

- We should like to keep support for devfs and regular device names in
  the installer; loosing that would mean no support for 2.2/2.4 installs
  (although those are likely to be dropped anyway) and no support for
  installs of Sarge and I think may be a problem for debian-edu.
  However, if it is unavoidable, we could drop this requirement.

- Are there likely to be architecture specific issues with persistent
  device naming?
- Or with filesystems other than ext2/ext3?

- Persistent device naming is mostly needed to get rid of errors on
  reboot. Most common case is where a system has multiple disk
  controllers and the order in which their drivers are loaded is
  different after the reboot than in d-i leading to a different order
  in device names.

- A special case is for installations from usb-stick in combination with
  a scsi or SATA harddisk controller. In that case d-i will see the USB
  stick as the first SCSI controller (sda) and the real SCSI/SATA
  harddisks will come after that. This also results in errors on reboot
  as the grub setup and fstab will be incorrect as then the usb stick will
  not be present and sda will be assigned to the real disk controller.
  Similar cases for installs to any kind of external disk drive.
  It seems to me that persistent device naming will probably fix fstab in
  this case, but possibly not the grub configuration.

- Probably unrelated, but worth mentioning. If the user installs to hdb
  and has BIOS set to boot from hdb, the grub configuration will be
  incorrect. (Same for hdc, hdd of course.)

- The last two issues are somewhat related and could maybe be solved by
  detecting this situation and asking the user which device the system
  will boot off. There are a number of bug reports against grub-installer
  about these two issues.

- Identify where changes will be needed. This will be at least partman
  and will probably include most bootloader installers.

Cheers,
FJP

Attachment: pgp9QEs2TKwcd.pgp
Description: PGP signature


Reply to: