On 8/17/20 9:01 PM, hobie of RMN wrote:
On 2020-08-17 16:42, hobie of RMN wrote:Hi, All - My brother has been issuing "mount /dev/sdb1" prior to backing up some files to a second hard disk. He lately upgraded to 'testing', and it appears (from result of running df) that what the system now calls /dev/sdb1 is what he has thought of as /dev/sda1, the system '/' partition. Thanks to the UUID= mechanism, his system still boots properly, but 'mount /dev/sdb1' is inappropriate now, could even be the path to madness. :) Two questions, then: (1) What caused this shift of device naming? And (2) How do we fix it? Is this something that can be changed in the BIOS? But, if so, what caused it to change in the first place? Thanks for your time and attenton.Please run the following commands as root and post the complete console session -- prompt, command issued, and output obtained: # cat /etc/fstab # mount Please post the complete console session demonstrating the issue with mount(8).
root@shelby:~# cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/sda1 during installation
UUID=3f50ca38-20f3-4a12-880c-a1283ac6e41b / ext4
errors=remount-ro 0 1
# swap was on /dev/sda5 during installation
UUID=ca191c62-2f38-4eae-b4e9-e21337edc198 none swap sw
0 0
/dev/sr0 /media/cdrom0 udf,iso9660 user,noauto 0 0
/dev/sr1 /media/cdrom1 udf,iso9660 user,noauto 0 0
root@shelby:~# mount
/dev/sdb1 on / type ext4 (rw,relatime,errors=remount-ro)
AIUI device node assignment is something the kernel does during boot. Drive nodes can change due to changing software, changing hardware, or both. Upgrading to testing is probably what caused the change. It's not something I would try to "fix". Do not mess with the BIOS/UEFI or CMOS settings.
The best answer is to use a stable identifier, such as a UUID or label, for the backup drive partition. Human-readable labels can be easier to type, but require a supported partitioning scheme (e.g. GPT) or filesystem (e.g. ext*). I would connect the backup drive, use blkid to find the UUID, create a mountpoint (e.g. /mnt/backup), and add an entry to /etc/fstab. You would then mount the drive via 'mount /mnt/backup'.
David