Firstly, create bootable pendrive by ISO, after creating boot installer, also copy the Elastix ISO file in the pendrive root space.

Let’s modify two files in pendrive root;

1) Pendrive root > isolinux > isolinux.cfg

We need to change the drive path from cdrom to hard-drive

Find these lines

label linux
kernel vmlinuz
append ks=cdrom:/ks_default.cfg initrd=initrd.img ramdisk_size=8192
label rhinoraid
kernel vmlinuz
append ks=cdrom:/ks_rhinoraid.cfg initrd=initrd.img ramdisk_size=8192
label nochoice
kernel vmlinuz
append ks=cdrom:/ks_nochoice.cfg initrd=initrd.img ramdisk_size=8192

Change the cdrom path to pendrive path

Replace the lines with

label linux
kernel vmlinuz
append ks=hd:sdb1:/ks_default.cfg initrd=initrd.img ramdisk_size=8192
label rhinoraid
kernel vmlinuz
append ks=hd:sdb1:/ks_rhinoraid.cfg initrd=initrd.img ramdisk_size=8192
label nochoice
kernel vmlinuz
append ks=hd:sdb1:/ks_nochoice.cfg initrd=initrd.img ramdisk_size=8192

 

2) Pendrive root > ks_default.cfg

Find this two lines

#Use CDROM installation media
cdrom

Replace this two lines with

#Use CDROM installation media
#cdrom
ignoredisk --drives=sdb

 

Again, find this two lines

#System bootloader configuration
bootloader --location=mbr

Replace this two lines with

#System bootloader configuration
bootloader --location=mbr --driveorder=sda,sdb

 

3) Now, you can start installation by pendrive.

When installing, choose Installation Method to Hard drive, and select /dev/sdb1