CR25iNG to SFOS fails to upgrade

Question

I am having an issue trying to upgrade a CR25iNG to SFOS. I have updated the device to latest cyberoam FW which is 10.6.5, reset to defaults, and also reboot to the older firmware 10.6.2 MR-1. I have tried 3 versions of the Sophos firmware SW-SFOS_16.05.3_MR-3.SFW-183.gpg, SW-SFOS_16.01.3_MR-2.SFW-265.gpg and SW-SFOS_16.01.4_MR-3.SFW-342.gpg. Each time I have tried either uploading or uploading plus boot it fails with this message. New Firmware could not be uploaded. Please refer online help for possible reasons. 
 Any help would be appreciated. 
 Thanks

Aditya Patel · Answer

HI Tony, 
 You may first need to check the Disk utilization, I would suspect that would be the case you are experiencing. 
 You may check the disk utilization via the command on console> system diagnostics show disk. 
 Options to resolve your issue 
 Purge some months of reports or Disable the Service of IPS and AV on your XG then upgrade the firmware. After the firmware is upgraded you may enable the AV and IPS again.