[Cisco-asr9k-ug] ASR 9k upgrade path from 5.3.x to 6.4.x?

[Job Snijders]

Dear all,

We're trying to figure out how to upgade from 5.3.4 to 6.4.1. Jumping
that far seems to pose significant challenges. Reviewing documents such
as and what we discovered during testing there seem to be a few hurdles
to clear.

https://supportforums.cisco.com/kxiwq67737/attachments/kxiwq67737/4441-docs-service-providers/4768/9/migrate_to_asr9k_64.pdf

1/ Some in our group suggested to ship management blades (already
upgraded to 6.4.1) around the world. But it seems we can't stage 6.4.1
on a management blade, starting with IOS XR 6.1.1 there is this "unified
FPD" thing. The LCs will not boot without first being upgraded to more a
recent FPD, which is only possible by upgrading to a recent version of
cXR.

2/ there are a few implications to the above. of course it will make the
upgrade process more painful, but it also effects sparing parts. If a LC
is shipped out and was previously booted on <= 5.x it wont come up in
6.4.1 eXR?

3/ An upgrade path such as 5.4.3 -> 6.0.1 -> 6.1.1 -> 6.4.1 will take
too long. We're not in a position to bring routers down for extended
periods of time for multiple installations (multiple hours), our
maintenance windows aren't long enough.

4/ as far as we understand turboboot, it doesn't upgrade the FPD or
has some restriction related to non-unified -> unified. So similar
problem as in 1?

5/ And what is the downgrade process in case something in 6.4.1 isn't to
your liking and you'd temporary want to back out?

Sooo.... in short - how are y'all doing in terms of upgrading to 64-bit XR? :-)

Kind regards,

Job

ps. Apologies if I'm sharing inaccurate information, corrections welcome.