A script that boots a VM, waits till it reports that it is on, then forces iSCSI rescans until a target devices is only. Very useful for iSCSI from internal VM

ESXI_iSCSI_Wait_Till_Mount.sh

#Originally inspired by this script https://jc-lan.org/2020/02/05/script-to-automatically-rescan-and-mount-software-iscsi-datastores-on-startup-for-esxi/

#This original script didn't work for me, as it didn't wait until the vm was confirmed on, so would boot loop if the vm didn't boot first time

#Designed to go in the ESXI host's local.sh file. This will mean vm autostart will not occur till after this script has executed

#Establish our timer
count=0

#Power on the guest VM with the specified Vmid
#use the command vim-cmd vmsvc/getallvms to find which Vmid to use
# the number '1' is the vmid in this example
vim-cmd vmsvc/power.on 1

#loop until the vm is actually powered on
while ! vim-cmd vmsvc/power.getstate 1 | grep on

do
	logger "local.sh: attempting to power on vm 1"
	vim-cmd vmsvc/power.on 1 2>&1 | logger &
	sleep 30
done

logger "local.sh: VM 1 should be on now"

#Now continuously rescan for the iSCSI device until it is found
#or the maximum time of 10 minutes is reached.
#This command will search all Logical Devices for one that has "Vendor_Name" in the Display Name (e.g., FreeNAS, TrueNAS)
while ! esxcfg-scsidevs -c | grep -q 'Vendor_Name'

#Alternatively if you have multiple iSCSI targets that share the same Display Name
#(iSCSI Vendor) then you may want to instead search by Volume Name.
#This method allows you to single out a specific server since Volume Name is user configurable.
#The command below will search for the volume name 'Your_custom_volume_name' and that Mounted status is true.
#while ! esxcli storage filesystem list | grep -q "Your_custom_volume_name.*true"
do
    #print some debugging info to the syslog
    logger "local.sh: Forcing rescan since iSCSI target is not yet available..."
    
    #Rescan SCSI HBAs to search for new Devices, remove DEAD paths and update path state. 
    #This operation will also run an claim operation equivalent to the claimrule run command and a filesystem rescan.
    esxcli storage core adapter rescan --all

    #Now wait (in seconds) before checking again
    sleep 30

    #Increase the timer
    count=`expr $count + 30`

    #Check if maximum time has been reached (in seconds)
    if [ $count -ge 600 ]
    then
       logger "local.sh: Aborting, maximum time reached while searching for iSCSI target."
       break
    fi
done

logger "local.sh: Search time for iSCSI target was" $count "seconds."


exit 0