I have successfully migrated my HP N54L from version 6.0.2 to 6.1.3 15152 and created a step by step guide below which worked for me.
First Please read the upgrade tutorial by Polanskiman and this thread!
Use this guide at your own risk. I won’t be held responsible for any loss of data or failures that may result in the use of this step by step guide!
1. Backup your data and system configs! You have the full responsibility!!!
2. Disable C1E setting in bios!!!
3. Start with the workaround script to copy network drivers at boot to prevent the HP micro server from not getting a network connection and become un-accessible
a. Create a shared folder called Scripts in volume1
b. Download the script update_patch.sh by Eduardo
c. Enable SSH port 22 in Control Panel / Terminal & SNMP
d. Use Putty to connect to your server log in with your admin account and password. Check that admin password is set.
e. In Putty to become super user type Sudo –i
f. Change permissions of your update file, type chmod 0744 /volume1/Scripts/update_patch.sh
g. Log out, exit putty, disable SSH access
h. Go to Control Panel / Tasks Scheduler and create a triggered task, select user root and select event boot up and then go to task settings and type in /volume1/Scripts/update_patch.sh and finally enable the task!
4. Go to Control Panel /Update & Restore and update to DSM 6.1.3-15152
5. When the server reboots turn it off and unplug your usb stick
6. Make a backup of your usb stick with image writer
7. Note VID, PID, mac address and serial of your grub config file of your usb stick
8. Write with Image writer the loader image file JunsMod102a-test-NICadd.img by Khile to your usb stick
9. Update the grub config file of your usb stick with VID, PID, serial number and mac address
10. Update the GRUB_VER file of your usb stick with DSM Version to 15152
11. Put back the updated USB stick to your server and start the server
12. Start Synology assistant to check when the server comes online, if it does not come online wait about 15 minutes for the update_patch script to run and to copy the network files to the right folder after that is done it will reboot. Mine rebooted twice however my server always needs to be turned off at boot as it does not reboot the usb stick for some reason.
If your migration does not work out for some reason you can reinstall by pulling out all the hard disks from the server and select forced install, when the server appears in the Synology assistant insert the hard disks and install fresh.