On 7/31/25 14:53, Andy Smith wrote:
Hi Eben,
[2TB HDD booting MBR to 256G SSD booting UEFI]
On Thu, Jul 31, 2025 at 01:41:19PM -0400, Eben King wrote:
eben@cerberus:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 238.5G 0 disk
└─sda1 8:1 0 238.5G 0 part
sdb 8:16 0 1.8T 0 disk
├─sdb1 8:17 0 953M 0 part /boot
├─sdb2 8:18 0 2G 0 part /
├─sdb3 8:19 0 20G 0 part /usr
To be honest I think I would probably just move some stuff to the SSD
and carry on booting MBR mode.
0. Have backups.
1. From single user mode or a live environment (even the "rescue" mode
from the Debain install medium) rsync the contents of /, /boot and
/usr to the single sda1 partition.
2. grub-install /dev/sda
3. Adjust /etc/fstab to mount / from sda1 and comment out /boot and
/usr.
4. Reboot the computer, making sure that the SSD appears first in the
boot order.
If it doesn't work for some reason, revert step 3 and then boot with
the HDD as first in the boot order to be back where you started.
This moves the majority of your OS to the SSD. It still boots in MBR
mode.
Is there a way to get grub to print at each boot the drive it lives on?
I don't want to be in the situation where everything appears to be
working, then one day I replace the HD and booting either doesn't work
or works differently.
I don't see any advantage to changing a working system from MBR to UEFI
booting unless there is specific need. I'd do that at next reinstall.
OK, thanks.
As a side note I would find this amount of partitions to juggle to be
really unwieldy. What do you do when one of them fills up and you can't
easily resize it because of the other partitions before and after it on
the disk?
The situation really doesn't come up that often. I added up the HD
partitions fdisk sees and got 855 GiB. That sounds a bit low, but not
out of the realm of possibility. There's plenty of buffer space around
each partition. I only upgraded from a 1T drive because those were
getting hard to find. I really don't need all this space, but I have it.
multiplier
953M 1 953 MiB
2G 1024 2048 MiB
20G 1024 20480 MiB
953M 1 953 MiB
300G 1024 307200 MiB
30G 1024 30720 MiB
130G 1024 133120 MiB
165G 1024 168960 MiB
74G 1024 75776 MiB
9G 1024 9216 MiB
75G 1024 76800 MiB
48G 1024 49152 MiB
855 GiB
No idea what sdd is:
"lsblk -o +model,vendor" may give more idea
eben@cerberus:~$ lsblk -o +model,vendor | grep sdd
sdd 8:48 1 0B 0 disk Dual SATA Bridge
Sabrent
Hmm, I have a PCIe -> 4xSATA card that's currently running the DVD
drive, but it's not by Sabrent:
04:00.0 SATA controller: Marvell Technology Group Ltd. 88SE9215 PCIe 2.0
x1 4-port SATA 6 Gb/s Controller (rev 11)
Well, all drives that should be accessible are, so I probably won't
worry too much about it.
