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I have a list of scsi disks that I need to remove. The list is considered random at best and changes from time to time. I want to remove everything except a predefined list that I have created. Let's assume for now that I only want to keep:


The command I need to execute is:

"echo 1 > /sys/block/sdX/device/delete"

Where X is the device to be removed.

I'm not good at bash scripting so I don't really know where to start.

To recap so I don't get DV'd for not being clear.

I need to "echo 1 > /sys/block/sdX/device/delete" for every sdX device on the system except for a predetermined list.

EDIT: After the answer below, this is what I've decided to use. "LocalDisks.txt" should contain lines like "/dev/sda"

exclude=$(cut -d/ -f3 LocalDisks.txt)

for sysfile in /sys/block/sd* ; do

dev=$(basename $sysfile)

if [[ $exclude == *$dev* ]] ; then
    echo "Device $dev excluded"

elif [ ! -w $del ] ; then
    echo "$del does not exist or is not writable"

    echo 1 > $del

share|improve this question
up vote 4 down vote accepted

Here's an approach that should work:

  • Get the list of sdX devices to exclude

    exclude=$(cut -d/ -f3 exclude.txt)
  • Iterate over the /sys/block/sdX directories:

    for sysfile in /sys/block/sd? ; do
  • Extract the sdX name from that path, and build the delete file name

      dev=$(basename $sysfile)
  • Check if that sdX is in the excluded list:

      if [[ $exclude == *$dev* ]] ; then
        echo "Device $dev excluded"
  • Check if you have appropriate write permissions on the delete file

      elif [ ! -w $del ] ; then
        echo "$del does not exist or is not writable"
  • Do the delete (not really)

        echo "echo 1 > $del"
  • You're done!

share|improve this answer
I do think that this will work out. However, I need to make one adjustment. I have so many disks that some are /dev/sdXX - if I add a question mark to the one you already have it only returns the /dev/sdXX and if there's only one question mark, it only returns the ones like /dev/sdX. Makes sense... How can it service both? – LVLAaron Feb 6 '12 at 23:57
I replaced the ? with a * – LVLAaron Feb 7 '12 at 0:10
Yep, that was the right thing to do there. I hadn't thought about what happens if you have a lot of drives. – Mat Feb 7 '12 at 13:08
Technically you gave me exactly what I asked for, I only specified one X. :) – LVLAaron Feb 7 '12 at 15:00

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