[tlug] automating SCSI (SATA) device add/remove

[Kalin KOZHUHAROV <me.kalin@example.com>]

Hi,

I have been pondering for quite some time at easy ways to automate
adding removal of SATA drives on my system with CLI.
I use different eSATA enclosures or SATA "drawers".

Adding usually happens automatic, unless the drive happens to take too
long to initialize... then I have to find the device (`dmesg`), then
for a message like this:

       [451944.216906] ata5: hard resetting link

I have to do:
      echo "- - -" >/sys/class/scsi_host/host4/scan
(see the off-by-one, ata5 is host4)


When I want to properly stop the drive before removing it, I have to do:
    hdparm -Y /dev/sdc
   echo 1 >/sys/bus/scsi/devices/host4/target4\:0\:0/4\:0\:0\:0/delete

Now, I got lost in /sys many times and I need help .... I guess there
is a shorter way from /dev/sdc to xyz/delete

Can you point me to an easier way/command to do the following:

1. (attach) When I see "ata5: hard resetting link" do COMMAND ata5 and
have it rescan the host
2. (detach) When I want to detach sdf, do COMMAND2 sdf and have it
powered down and remove the device from kernel


Cheers,
Kalin.