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Linux's persistent naming scheme for disks

linux kernel monkey log - Tue, 10/06/2008 - 4:49pm

At OLS this year, I mentioned about the persistent device naming scheme that Kay demoed. This is now implemented in three distros (OpenSUSE, Gentoo, and Debian) for people to play around with (maybe four, haven't looked at Red Hat rawhide in a while.) So, if you want to see how this is solved for Linux, try one of those distros out and look at /dev/disk:

$ tree /dev/disk/
/dev/disk/
|-- by-id
|   |-- ata-TOSHIBA_MK4018GAP_23388192T -> ../../hda
|   |-- ata-TOSHIBA_MK4018GAP_23388192T-part1 -> ../../hda1
|   |-- ata-TOSHIBA_MK4018GAP_23388192T-part2 -> ../../hda2
|   |-- ata-TOSHIBA_MK4018GAP_23388192T-part3 -> ../../hda3
|   |-- ata-TOSHIBA_MK4018GAP_23388192T-part4 -> ../../hda4
|   |-- usb-Generic_USB_Flash_Drive_200506062389 -> ../../sdd
|   |-- usb-Generic_USB_Flash_Drive_200506062389-part1 -> ../../sdd1
|   |-- usb-Lexar_Media_Inc._CF_20030128160726900 -> ../../sdb
|   |-- usb-Lexar_Media_Inc._CF_20030128160726900-part1 -> ../../sdb1
|   |-- usb-Lexar_Media_Inc._SD.MS_20030128160726900 -> ../../sdc
|   `-- usb-Lexar_Media_Inc._SM.xD_20030128160726900 -> ../../sda
|-- by-label
|   |-- 1YET57WW -> ../../sdd1
|   |-- EOS_DIGITAL -> ../../sdb1
|   `-- home -> ../../hda4
|-- by-path
|   |-- pci-0000:00:0f.0-ide-0:0 -> ../../hda
|   |-- pci-0000:00:0f.0-ide-0:0-part1 -> ../../hda1
|   |-- pci-0000:00:0f.0-ide-0:0-part2 -> ../../hda2
|   |-- pci-0000:00:0f.0-ide-0:0-part3 -> ../../hda3
|   |-- pci-0000:00:0f.0-ide-0:0-part4 -> ../../hda4
|   |-- usb-0x05dc-0xb18d:0:0:0 -> ../../sda
|   |-- usb-0x05dc-0xb18d:0:0:1 -> ../../sdb
|   |-- usb-0x05dc-0xb18d:0:0:1-part1 -> ../../sdb1
|   |-- usb-0x05dc-0xb18d:0:0:2 -> ../../sdc
|   |-- usb-0x1043-0x8006:0:0:0 -> ../../sdd
|   `-- usb-0x1043-0x8006:0:0:0-part1 -> ../../sdd1
`-- by-uuid
    |-- 1553-17E8 -> ../../sdd1
    |-- 599b4559-2591-4649-a0e2-2547ef07cf33 -> ../../hda2
    |-- 7e80a6b0-918f-407b-a9d5-70858980a4ce -> ../../hda1
    `-- d6d10936-82a6-4884-8317-784c90a63830 -> ../../hda4

This machine has:

  • a single ide hard drive with 4 partitions, one of them labeled home.
  • a USB storage reader (3 slots, 6 or so storage types), with a Compact Flash card in it.
  • a USB flash stick with the label 1YET57WW on its first partition (why, I have no idea, it was a give-away at OSCON this year...)

So, another huge bureaucratic mess gives no real help and the developers go off and solve the problem on their own. When will they ever learn...