Beginners Questions • [O/S] How to configure SAN boot disk for multipath?

Hi there

I've spend a few days reading to figure this out and have some clues but haven't managed to get it running. I am hoping someone will be able to point me in the right direction please?

I have a small number of HP servers connected via FC to a Huawei SAN, where they boot and run Debian 12. I select only "standard system utilities" & "ssh server" during the install but drop to the shell to add the following: "network-manager", "multipath-tools" & "multipath-tools-boot".

The system installs and boots into Debian fine, and can see four paths to the boot LUN:

*****

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 30G 0 disk
├─sda1 8:1 0 512M 0 part
├─sda2 8:2 0 28.5G 0 part
└─sda3 8:3 0 976M 0 part
sdb 8:16 0 30G 0 disk
├─sdb1 8:17 0 512M 0 part /boot/efi
├─sdb2 8:18 0 28.5G 0 part
└─sdb3 8:19 0 976M 0 part
sdc 8:32 0 30G 0 disk
├─sdc1 8:33 0 512M 0 part
├─sdc2 8:34 0 28.5G 0 part
└─sdc3 8:35 0 976M 0 part
sdd 8:48 0 30G 0 disk
├─sdd1 8:49 0 512M 0 part
├─sdd2 8:50 0 28.5G 0 part /
└─sdd3 8:51 0 976M 0 part [SWAP]

*****

However I cannot get it to recognise these as a singular mpath. If I add another new LUN post-install it picks it up as an mpath so I believe multipath is running correctly.

The multipath.conf file looks like this:

*****

defaults {
find_multipaths yes
user_friendly_names yes
}

blacklist {
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]"
devnode "^hd[a-z]"
devnode "^cciss!c[0-9]d[0-9][p[0-9]]"
}

devices {
device {
vendor "HUAWEI"
product "XSG1"
path_grouping_policy group_by_prio
path_checker tur
prio alua
path_selector "round-robin 0"
failback immediate
no_path_retry 15
}
}

*****

From what I've read, I believe I need to regenerate initramfs to include multipathing? I've tried: which regenerates but does not provide multipathing for this boot LUN.

When installing Alma Linux on the same hardware and multipath.conf the OS recognises the boot LUN as mpath with no issues, as shown below:

*****

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
└─mpathb 253:0 0 50G 0 mpath
├─mpathb1 253:2 0 600M 0 part /boot/efi
├─mpathb2 253:3 0 1G 0 part /boot
└─mpathb3 253:4 0 48.4G 0 part
├─almalinux-root 253:5 0 45.4G 0 lvm /
└─almalinux-swap 253:6 0 3G 0 lvm
sdb 8:16 0 2T 0 disk
└─mpathc 253:1 0 2T 0 mpath
└─vg_data-lv_data 253:7 0 2T 0 lvm /data
sdc 8:32 0 50G 0 disk
└─mpathb 253:0 0 50G 0 mpath
├─mpathb1 253:2 0 600M 0 part /boot/efi
├─mpathb2 253:3 0 1G 0 part /boot
└─mpathb3 253:4 0 48.4G 0 part
├─almalinux-root 253:5 0 45.4G 0 lvm /
└─almalinux-swap 253:6 0 3G 0 lvm
sdd 8:48 0 2T 0 disk
└─mpathc 253:1 0 2T 0 mpath
└─vg_data-lv_data 253:7 0 2T 0 lvm /data
sde 8:64 0 50G 0 disk
└─mpathb 253:0 0 50G 0 mpath
├─mpathb1 253:2 0 600M 0 part /boot/efi
├─mpathb2 253:3 0 1G 0 part /boot
└─mpathb3 253:4 0 48.4G 0 part
├─almalinux-root 253:5 0 45.4G 0 lvm /
└─almalinux-swap 253:6 0 3G 0 lvm
sdf 8:80 0 2T 0 disk
└─mpathc 253:1 0 2T 0 mpath
└─vg_data-lv_data 253:7 0 2T 0 lvm /data
sdg 8:96 0 50G 0 disk
└─mpathb 253:0 0 50G 0 mpath
├─mpathb1 253:2 0 600M 0 part /boot/efi
├─mpathb2 253:3 0 1G 0 part /boot
└─mpathb3 253:4 0 48.4G 0 part
├─almalinux-root 253:5 0 45.4G 0 lvm /
└─almalinux-swap 253:6 0 3G 0 lvm
sdh 8:112 0 2T 0 disk
└─mpathc 253:1 0 2T 0 mpath
└─vg_data-lv_data 253:7 0 2T 0 lvm /data

*****

So I believe I am missing something specific to Debian (which I am new to). Would appreciate any suggestions please?

Hope someone can help, many thanks.

Statistics: Posted by Verulam — 2024-07-25 13:24 — Replies 0 — Views 11

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