Backplane Presentation in Linux

Hardware
1 
root@andromeda:/dev/disk/by-path# ls -l
total 0
lrwxrwxrwx 1 root root  9 Dec 18 05:21 pci-0000:01:00.0-sas-phy0-lun-0 -> ../../sdf
lrwxrwxrwx 1 root root  9 Dec 18 05:22 pci-0000:01:00.0-sas-phy10-lun-0 -> ../../sdo
lrwxrwxrwx 1 root root  9 Dec 18 05:22 pci-0000:01:00.0-sas-phy12-lun-0 -> ../../sdj
lrwxrwxrwx 1 root root  9 Dec 18 05:22 pci-0000:01:00.0-sas-phy13-lun-0 -> ../../sdl
lrwxrwxrwx 1 root root  9 Dec 18 05:22 pci-0000:01:00.0-sas-phy14-lun-0 -> ../../sdp
lrwxrwxrwx 1 root root  9 Dec 18 05:22 pci-0000:01:00.0-sas-phy15-lun-0 -> ../../sdq
lrwxrwxrwx 1 root root  9 Dec 18 05:21 pci-0000:01:00.0-sas-phy1-lun-0 -> ../../sde
lrwxrwxrwx 1 root root  9 Dec 18 05:21 pci-0000:01:00.0-sas-phy2-lun-0 -> ../../sdd
lrwxrwxrwx 1 root root  9 Dec 18 05:21 pci-0000:01:00.0-sas-phy3-lun-0 -> ../../sdc
lrwxrwxrwx 1 root root  9 Dec 18 05:21 pci-0000:01:00.0-sas-phy4-lun-0 -> ../../sdb
lrwxrwxrwx 1 root root  9 Dec 18 05:21 pci-0000:01:00.0-sas-phy5-lun-0 -> ../../sda
lrwxrwxrwx 1 root root  9 Dec 18 05:21 pci-0000:01:00.0-sas-phy6-lun-0 -> ../../sdh
lrwxrwxrwx 1 root root  9 Dec 18 05:21 pci-0000:01:00.0-sas-phy7-lun-0 -> ../../sdg
lrwxrwxrwx 1 root root  9 Dec 18 05:22 pci-0000:01:00.0-sas-phy8-lun-0 -> ../../sdm
lrwxrwxrwx 1 root root  9 Dec 18 05:21 pci-0000:01:00.0-sas-phy9-lun-0 -> ../../sdi

Is it safe to assume this is 1-1 through 1-15, numbered from phy0 upwards and somehow missing out phy11 (presumably that’s the missing 16th drive?).

I’m looking to do something with consistent / persistent device naming as I setup ZFS.

2

Short answer - Probably :grinning:

Looks like you must be using your own HBA or custom build? 45Drives has a utility called dalias which setups the /dev/disk/by-path to a slot alias “1-1, 1-2, 1-3, etc.” Basically you setup your layout (or use the sample for HL15) and then you insert or remove a hard drive in each slot.

You can grab dalias off their github or repo:
GitHub - 45Drives/tools: It’s only 4 to 5 drives, its not Rocket Appliances - Ricky

Even if you don’t plan on using the alias in your ZFS pool, this should help verify your assumptions and can be used to show your drives (along with this information) in cockpit via “45Drives Disks” page.

This handy for anyone doing a fresh install of rocky or looking to move to ubuntu or debian on a full build HL15.

1 Like
3

If this is a Full Build from us then you should be able to use “dmap” It will then alias the server with the 1-1,1-2, etc slots.

or if you want to use the PCIE lens we have a guide here KB450269 - Physical Locations to Slot from UUID in Linux - 45Drives Knowledge Base

If this was not wired by use the cables could be swapped around so the groups of 4 drives could be in the wrong orders