forgot boot.ldr on upgrade

[MartK]

Hello,
I recently upgraded two 7750 SR-7 from 12.0.R1 to 13.0.R5.
On one 7750 I copied the new boot.ldr to cf3:\
On the other one I forgot that so it uses the old boot.ldr from 12.0.

My question is: What exactly does boot.ldr do?
Do I need to restart it with the new boot.ldr? It seems to work just fine. I don't want to reload it if I don't have to.
It's the same version on mda and iom on both 7750.

[mivens]

It's a small executable that amongst other things, allows you to choose which version of SR OS to run and where from and which configuration file to use to load the config. It brings up the ports on the CPM so you can boot an image or load a config from a remote location over the network as well as from local flash.

If the boot loader is not the same as the main version of SR OS then in theory there is a difference in hardware support which might hurt you in the future. So for example, someone could upgrade to a CPM5 in future then find it doesn't boot because there's no boot.ldr support. In your case, between R12 and R13 with your hradware that may not affect you.

I would copy the new boot.ldr in place then reload the standby CPM verifying it comes back up. Then do a redundancy switchover and do the same with the new standby SF/CPM. That way you have verified the new boot.ldr is working with minimal/no interruption depending on your setup.

[MartK]

Thanks for the reply.
There is a differnce in file size of the boot.ldr so something has changed.
We only have one CPM per 7750. I'm going to reboot it with the correct boot.ldr.
Better to do it now then later.

[gargoyle]

HI, How about boot.ldr in TiMOS image file directory (cf3:/TiMOS-xx)?
does it has same function with boot.ldr in root driectory (cf3:/ ) ?

[mivens]

The system will not look for a boot.ldr file in that directory.

It's good practice to keep a backup of the boot.ldr file in the relevant image file directory so you can copy it to the root when changing image.