My problem is with Firmware, While I am on 4.2.26 incremental backup works fine, first full backup then incremental back all goes fine. When I am upgrading the firmware to 4.2.27 or any other version the backup takes a full backup every time.
Please help me as my firmware is too old & I am afraid that I am vulnerable to outside attacks
If you are up to the task of restoring all of your configuration and data, your 4200 can be migrated to OS6 for a really big jump in Debian versions. It's not supported by Netgear, but your 4200V1 is probably out of warranty, anyway. Since the migration requires a factory default to deal with the new BTRFS fomat, you will have to re-create the configuration (which also can't be saved in OS4.2.x and restored in 6.x) and restore all the data. All of my active legacy NASes now run OS6.x, including two 4200V2's.
