ATA and SATA Disk Names in Linux – Understanding the Differences

hard-disklinuxpatasata

Assume that we have two disks, one master SATA and one master ATA. How will they show up in /dev?

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Depending on your SATA driver and your distribution's configuration, they might show up as /dev/hda and /dev/hdb, or /dev/hda and /dev/sda, or /dev/sda and /dev/sdb. Distributions and drivers are moving towards having everything hard disk called sd?, but PATA drivers traditionally used hd? and a few SATA drivers also did.

The device names are determined by the udev configuration. For example, on Ubuntu 10.04, the following lines from /lib/udev/rules.d/60-persistent-storage.rules make all ATA hard disks appear as /dev/sd* and all ATA CD drives appear as /dev/sr*:

# ATA devices with their own "ata" kernel subsystem
KERNEL=="sd*[!0-9]|sr*", ENV{ID_SERIAL}!="?*", SUBSYSTEMS=="ata", IMPORT{program}="ata_id --export $tempnode"
# ATA devices using the "scsi" subsystem
KERNEL=="sd*[!0-9]|sr*", ENV{ID_SERIAL}!="?*", SUBSYSTEMS=="scsi", ATTRS{vendor}=="ATA", IMPORT{program}="ata_id --export $tempnode"

Related Solutions

How to tell if the hard drive is PATA or SATA

To see the device description for the controller (assuming an internal (PCI) controller), which usually contains SATA for SATA controllers:

lspci -d $(cat /sys/block/sda/device/../../../vendor):$(cat /sys/block/sda/device/../../../device)

If you want to type less, just browsing the output of lspci is likely to give you the answer in a laptop (many desktop have both kinds of interfaces so you'd have to look up the drive you're interested in).

If that doesn't give you the answer, to see what driver is providing sda (you can then look up whether that driver is for a PATA or SATA controller):

readlink -f /sys/block/sda/device/../../../driver

Linux – Match PCI address of SATA controller and SCSI address of attached disks

I think you can get what you want by cross referencing the output from lshw -c disk and this command, udevadm info -q all -n <device>.

For example

My /dev/sda device shows the following output for lshw:

$ sudo lshw -c disk
  *-disk                  
       description: ATA Disk
       product: ST9500420AS
       vendor: Seagate
       physical id: 0
       bus info: scsi@0:0.0.0
       logical name: /dev/sda
       version: 0003
       serial: 5XA1A2CZ
       size: 465GiB (500GB)
       capabilities: partitioned partitioned:dos
       configuration: ansiversion=5 signature=ebc57757

If I interrogate the same device using devadm I can find out what it's DEVPATH is:

$ sudo udevadm info -q all -n /dev/sda | grep DEVPATH
E: DEVPATH=/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda

This string has all the info you're looking for regarding this device. The PCI address, "0000:00:1f.2", along with the SCSI address, "0:0:0:0". The SCSI address is the data in the 6th position if you break this data up on the forward slashes ("/").

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Related Solutions

How to tell if the hard drive is PATA or SATA

Linux – Match PCI address of SATA controller and SCSI address of attached disks

For example

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