SCSI HOWTO

Various recipies for SCSI maintenance.

Hot Swap SCSI

This is only supported on a machine with Hot Swap SCSI bays.

Unmount all volumes on the drive and/or remove it from RAID configurations and/or stop swap.

Tell linux that the device is gone. You need to know the following.
- Host Adapter number (first is zero)
- SCSI channel (first is zero)
- SCSI ID (normally 0 through 7)
- SCSI LUN (normally 0)
You can view the current SCSI devices with the following command.

  # cat /proc/scsi/scsi

You can find out where Linux mounted your disk with the following command.

  # dmesg | grep 'Attached scsi disk'
  Attached scsi disk sda at scsi0, channel 0, id 0, lun 0
  Attached scsi disk sdb at scsi0, channel 0, id 1, lun 0
  Attached scsi disk sdc at scsi0, channel 0, id 2, lun 0
  Attached scsi disk sdd at scsi0, channel 0, id 3, lun 0

Use the following command, but replace A with the adapter number, C with the channel number, I with the SCSI ID and L with the LUN.

  # echo "scsi remove-single-device A C I L" >/proc/scsi/scsi

You can verify that the drive is gone by checking /proc/scsi/scsi.

  # cat /proc/scsi/scsi

Now pull out the drive and replace it. Once the new drive has been installed, tell Linux.

  # echo "scsi add-single-device A C I L" >/proc/scsi/scsi

If all goes well, you can now repartition and mount the replacement drive.