Fresh install of 9.5 on raid 1

General Discussion & Chat
1

This should not be a big deal, but I’ve had 100% failure
I have two 2TB drives. partition 1 is /boot, 2 is /boot/eft, 3 is swap. Now, fot the rest of the drive I want RAID 1, with two partitions, 250GB for /, and the rest for /home.

I created the RAID1, and partitioned it.
When I try to run the graphical installer, it only sees the GPT, and thinks it’s RAID 1, but not the partitions. In test mode, it at least it sees /dev/md1, but not /dev/md1p1 and /dev/md1p2.

How do I get around this, or is this a bug?

2

Array in partition, partition in array – I’m not totally sure what you did.

Logically, the first drive would have four partitions:
A: ESP
B: /boot
C: swap
D: RAID
The second drive would have at least one partition “E”, same size as D.

The D and E would be the legs of one RAID1 array. IME, one does not put partition table into software RAID1 array. One puts filesystem into the array.

Perhaps one could put LVM PV on the array? Then one could have multiple LVs in it. Is that what you did?

Then again, LVM supposedly has its own mirror feature, so one could have PVs on D and E, and let LVM do the mirroring without RAID. No idea whether the installer supports that.

The surefire way is to have not one, but two partitions on both drives for two RAID1 arrays: one for the 250GB / and the other, larger, for the /home. The downside is that then you lack the flexibility of LVM. Then again, the default filesystem – XFS – does not support shrinking, so such changes will be non-trivial anyway.

3

Really don’t want to screw with LVM.
You’re saying that I need two separate RAID 1s, rather than one with two partitions. If that’s what I need to do…

4

That is the traditional way: one filesystem per array. Being simple, the installer and installed system should cope with that.

5

Well, I redid the drives. And screwed around with the GUIDs - I cloned sda, to b, finally just recreated the layout manually with parted.

The almalinux install FAILS, 100% with raids. I’ve tried graphical mode, which in destination 1 and 2, with 0 bytes, and says that they’re part of a raid array missing one drive. I change to shell, and the raids have not been started. I start, but I cannot get back from the shell to the graphical mode.

Redid the partitioning with the RAID partitions as ext, rather than pri. Now the text mode installer - after I change windows and start the arrays, and rescan DOES NOT SEE the raids at all.

Suggestions, or shall I file a bug report on a) not being able to get back from shell to graphical, and b) not starting raids that were preconfigured in shell?
So I tried text mode install.

6

The MBR partition table has pri and ext. The GPT does not. The UEFI boot uses
ESP (EFI System Partition) that only GPT can have.

I do usually use gdisk if I have to partition manually.

IIRC, the last time I’ve set up software RAID (on install) was with CentOS 6. Cannot remember details, but the installer’s GUI had some way to customize the “backend”.
This is what Red Hat says: Chapter 10. Customizing the system in the installer | Red Hat Product Documentation

I did found one machine with software RAID, with legacy boot (i.e. MBR):

[root@x ~]# fdisk -l /dev/sda

Disk /dev/sda: 500.1 GB, 500107862016 bytes, 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x6f097d2a

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     2097151     1047552   fd  Linux raid autodetect
/dev/sda2         2097152   976773119   487337984   fd  Linux raid autodetect

[root@x ~]# lsblk -i
NAME              MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                 8:0    0 465.8G  0 disk  
|-sda1              8:1    0  1023M  0 part  
| `-md3             9:3    0  1023M  0 raid1 /boot
`-sda2              8:2    0 464.8G  0 part  
  `-md4             9:4    0 464.7G  0 raid1 
    `-vg1-sysC7   253:0    0    20G  0 lvm   /
sdb                 8:16   0 465.8G  0 disk  
|-sdb1              8:17   0  1023M  0 part  
| `-md3             9:3    0  1023M  0 raid1 /boot
`-sdb2              8:18   0 464.8G  0 part  
  `-md4             9:4    0 464.7G  0 raid1 
    `-vg1-sysC7   253:0    0    20G  0 lvm   /

and another, where RAID1 was added afterwards for data disks:

[root@y ~]# gdisk -l /dev/nvme0n1
GPT fdisk (gdisk) version 1.0.7

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/nvme0n1: 3125627568 sectors, 1.5 TiB
Model: Dell Express Flash PM1725a 1.6TB AIC    
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): E227BE25-BBEF-4D31-9F41-7FC1BC5306DC
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 3125627534
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048      3125627534   1.5 TiB     FD00  nvme0

The array creation must have been:

gdisk /dev/nvme0n1
gdisk /dev/nvme1n1
mdadm -C md0 --level=1 --raid-devices=2 /dev/nvme0n1p1 /dev/nvme1n1p1

(where gdisk was used interactively)

IIRC, one can switch between various virtual consoles and the GUI part of installer with
Ctrl-Alt-Fn, where n is 1, 2, … 6

The installer does, on bootup, enumerate devices. If one does manual changes to partitioning from installers shell prompt, that might be after enumeration and hence the (GUI) installer will not know about that. Trivial workaround is to reboot the installer.

If installer does not detect existing partitions nor auto-assemble RAID arrays, then question is why not?

7

Have you, personally, tried to switch between the GUI installer and the shell? I did, numerous times, and I DO NOT GET A GUI. I only get a text-mode screen showing the last things printed before it brought up the GUI.

Your last paragraph - how do I reboot the installer, after bringing up the RAIDS? The only way I know is to reboot the computer.

gdisk? I know nothing of that. I’ve always used parted and mdadm.

I suppose I can delete and repartition again, new GPT, and all pri partitions, which is what I had in the beginning.

8

Just did, on two machines. On the first the Ctrl-Alt-Fn do nothing – cannot see anything but the GUI.

On the second F1 and F4 have some output-only text consoles, F2, F3, and F5 have shell prompt, and F6 has the GUI.

Indeed. The GUI partitioning tool should see (after reboot) what is already on the drives and lets add, remove, and modify.

fdisk used to support only MBR tables. The gdisk is “looks like fdisk, but for GPT”.

That is what I’d do – wipe and try again.