smartctl wrapper for H240 HBA

#!/bin/bash

# -----------------------------------------------------------------
# Copyright (c) 2021 BestSolution.at EDV Systemhaus GmbH
# All Rights Reserved.
#
# This software is released under the terms of the
#
#            "GNU Affero General Public License"
#
# and may only be distributed and used under the terms of the
# mentioned license. You should have received a copy of the license
# along with this software product, if not you can download it from
# https://www.gnu.org/licenses/agpl-3.0.en.html
#
# Author: [email protected]
# -----------------------------------------------------------------
#
#  smartctl_cciss.sh
#
#  Wrapper that converts
#
#    '$ smartctl [...] /dev/sda' to '$ smartctl -d cciss,0 [...] /dev/sda'
#    '$ smartctl [...] /dev/sdb' to '$ smartctl -d cciss,1 [...] /dev/sdb'
#    '$ smartctl [...] /dev/sdc' to '$ smartctl -d cciss,2 [...] /dev/sdc'
#    ...
#    '$ smartctl [...] /dev/sdp' to '$ smartctl -d cciss,15 [...] /dev/sdp'
#
#  Per definition (see man smartctl(8)), the maximum number of devices
#  supported by the cciss driver is 15, so the /dev/sdp is the "highest"
#  device accepted (p=15).
#
#  This is useful for certain HP RAID/HBA controllers that expose the block
#  devices they control as /dev/sdX, but still require '-d cciss,N' to be
#  present when used with smartctl.
#
#  At the bottom line, this saves you the extra commandline switch  plus at
#  the same time allows other tools to read out the SMART values without any
#  further configuration on their side (eg. the proxmox admin interface
#  showing SMART values).
#
#  To wrap the original smartctl binary using this script, rename the script
#  to /usr/sbin/smartctl.orig and use this script as a replacement, eg like
#  this:
#
#  $ mv /usr/sbin/smartctl /usr/sbin/smartctl.orig
#  $ cp /path/of/the/downloaded_wrapper/smartctl_cciss.sh /usr/sbin/smartctl
#  $ chmod 755 /usr/sbin/smartctl
#
#  Later updates of the smartmontools package will probably overwrite the
#  wrapper, so what you can do to prevent this is to make the in place
#  wrapper immutable like this:
#
#  $ chattr +i /usr/sbin/smartctl
#
#  ... but this may have some sideffects afterwards (eg. updates might
#  complain that they cannot update the now immutable file).
#
#  This is a little bit hackish, but it does the job well enough for me :)

SMARTCTL=/usr/sbin/smartctl.orig
OPTIONS=("$@")

# build up map
char_index=({a..h})
declare -A num_map
for((i=0; i < ${#char_index[*]}; ++i)); do
    num_map[${char_index[i]}]=$i
done

for((i=1; i<$#; ++i)); do
    device_letter="${OPTIONS[i]#/dev/sd}"
    # only proceed if the given device ends with [a-p]
    if [[ ! -z "${num_map[$device_letter]:-}" ]]; then
        cciss_device="-d cciss,${num_map[$device_letter]}"
        # add the "-d cciss,X" option to the list of options
        OPTIONS=($cciss_device "${OPTIONS[@]}")
    fi
done

# build up map
char_index=({i..p})
declare -A num_map
for((i=0; i < ${#char_index[*]}; ++i)); do
    num_map[${char_index[i]}]=$i
done

for((i=1; i<$#; ++i)); do
    device_letter="${OPTIONS[i]#/dev/sd}"
    # only proceed if the given device ends with [a-p]
    if [[ ! -z "${num_map[$device_letter]:-}" ]]; then
        cciss_device="-d cciss,${num_map[$device_letter]}"
        # add the "-d cciss,X" option to the list of options
        OPTIONS=($cciss_device "${OPTIONS[@]}")
    fi
done

exec $SMARTCTL "${OPTIONS[@]}"