pls suggest which device to select for grub-pc

nirvaanr · 02-12-2021, 10:09 PM

Hi

On my Debian 10 Server, when I ran "apt -y install gnupg2 software-properties-common" it popped-up a menu with "congiruing grub-pc" asking where to install Grub. I have no idea if it's MBR or /boot and also I have RAID-0 of 4 disks.

Pls see https://i.snipboard.io/GhQW4P.jpg

Code:

$  cat /proc/mdstat
Personalities : [raid1] [raid0] [linear] [multipath] [raid6] [raid5] [raid4] [raid10]
md125 : active raid0 sdd4[3] sdc4[2] sdb4[1] sda4[0]
      4186112 blocks super 1.2 512k chunks

md126 : active raid1 sdd3[3] sdc3[2] sdb3[1] sda3[0]
      4189184 blocks super 1.2 [4/4] [UUUU]

md127 : active raid0 sdd5[3] sdc5[2] sda5[0] sdb5[1]
      31230402560 blocks super 1.2 512k chunks

md2 : active raid1 sdb2[1] sdd2[3] sdc2[2] sda2[0]
      1048512 blocks [4/4] [UUUU]

unused devices: <none>
$

$

Code:

$   df -Ph
Filesystem      Size  Used Avail Use% Mounted on
udev            7.8G     0  7.8G   0% /dev
tmpfs           1.6G  153M  1.5G  10% /run
/dev/md127       29T   12T   18T  40% /
tmpfs           7.9G     0  7.9G   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           7.9G     0  7.9G   0% /sys/fs/cgroup
/dev/md125      3.9G   18M  3.7G   1% /tmp
/dev/md2       1008M   91M  867M  10% /boot
tmpfs           1.6G     0  1.6G   0% /run/user/1000
$

Code:

$  [ -d /sys/firmware/efi ] && echo UEFI || echo BIOS
BIOS
$

Pls advise which devices i need to select for grub install, thanks!

rnturn · 02-13-2021, 12:07 AM

Quote:

Originally Posted by nirvaanr

... also I have RAID-0 of 4 disks.

Pls see https://i.snipboard.io/GhQW4P.jpg

Code:

$  cat /proc/mdstat
Personalities : [raid1] [raid0] [linear] [multipath] [raid6] [raid5] [raid4] [raid10]
md125 : active raid0 sdd4[3] sdc4[2] sdb4[1] sda4[0]
      4186112 blocks super 1.2 512k chunks

md126 : active raid1 sdd3[3] sdc3[2] sdb3[1] sda3[0]
      4189184 blocks super 1.2 [4/4] [UUUU]

md127 : active raid0 sdd5[3] sdc5[2] sda5[0] sdb5[1]
      31230402560 blocks super 1.2 512k chunks

md2 : active raid1 sdb2[1] sdd2[3] sdc2[2] sda2[0]
      1048512 blocks [4/4] [UUUU]

unused devices: <none>
$

$

Code:

$   df -Ph
Filesystem      Size  Used Avail Use% Mounted on
udev            7.8G     0  7.8G   0% /dev
tmpfs           1.6G  153M  1.5G  10% /run
/dev/md127       29T   12T   18T  40% /
tmpfs           7.9G     0  7.9G   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           7.9G     0  7.9G   0% /sys/fs/cgroup
/dev/md125      3.9G   18M  3.7G   1% /tmp
/dev/md2       1008M   91M  867M  10% /boot
tmpfs           1.6G     0  1.6G   0% /run/user/1000
$

The grub error messages seems to indicate that you've made changes to the boot configuration. Can you elaborate on what changes have been made?

Q: Why put almost everything on a RAID0 device as opposed to a RAID5? (Or a RAID1+0?) With a RAID0 the system (well, "/" and "/tmp") will be a total loss of data should a single disk suffer a failure. Plus, many would consider a 1T boot partition overkill.

nirvaanr · 02-13-2021, 01:13 AM

Quote:

Originally Posted by rnturn

The grub error messages seems to indicate that you've made changes to the boot configuration. Can you elaborate on what changes have been made?

AFAIK I didn't do anything else other than trying to install those couple software packages. I just need to select correct partition/MBR. Is there any command to know where GRUB is installed on a machine? MBR/sda/md127.

Quote:

Originally Posted by rnturn

Q: Why put almost everything on a RAID0 device as opposed to a RAID5? (Or a RAID1+0?) With a RAID0 the system (well, "/" and "/tmp") will be a total loss of data should a single disk suffer a failure. Plus, many would consider a 1T boot partition overkill.

Because there's no useful data on it but we need highest possible I/O speed.

/boot is 1GB (1008M) not 1TB.