Routing

Hi

Just wanted to share some experince with ISSU and see if anyone has any comments/input.

We had a planned upgrade between junos versions 9.6 and 10.4. According to the release notes this should be an OK upgrade. We run MX-240/480 with GRES and NSR and therefore we have to perform ISSU. In our lab we do not have double routing-engines, so i could not verify this upgrade in the exact production setup before hand. I read up on the relevant documentation and guidelines and did the preparations. This is what happened:

When i issue the command "request system software in-service-upgrade jinstall-10.4R7.5-domestic-signed.tgz reboot" it starts the validation. The validation breaks with the output: 

/usr/libexec/ld-elf.so.1: Shared object "libisc.so.2" not found, required by "mgd" 
Validation failed 
WARNING: Current configuration not compatible with ...

I managed to find some posts about people having similar problems, but in a "normal" upgrade senario. One solution was to run the upgrade with "no-validation". This is not an option for ISSU.

I ended up upgrading in two steps: from 9.6 to 10.0, then to the 10.4 i wanted to run. I estimate that a full ISSU on my boxes takes roughly 20 mins per RE, so 40ish minutes. Having to upgrade in two steps really hurt.

I really think that this type of information should be in the release notes.

have a nice weekend,

Karl

Hi

AFAIK they support only 3-release jump at a time, and it was in release notes.

Not sure about EEOL releases, do you mean it is your case?

Hi Pk

If there is a 3-jump rule, i was not aware of that. We try to stick to EEOL-releases for MX. I thought the principle was that the fourth quarter release (i.e. year.4Rxxx) is the EEOL. If you can only jump 3 releases that would mean you cannot go between EEOL?

Our experience is that the plattform is so stable that upgrades is actually the most likely reason for service interruption. We try to do as few upgrades as possilbe, while staying on a version with support.

Thanks for your input. Ill look for more info on a general "jump-rule". I still think that it could be much clearer what the minimum version is to make a validated upgrade to version X. I spent quite some time looking and was sure i was going for a supported upgrade.

cheers

Karl

Hi

I'm happy to hear that you found Junos so stable (especially considering that
you used R1 release, which I personally never recommend to do...)

Yes, a 3-release rule is still out there, see

http://www.juniper.net/techpubs/en_US/junos10.4/information-products/topic-collections/release-notes/10.4/junos-release-notes-10.4.pdf

"For upgrades and downgrades to or from a non-EEOL release, the current policy is that
you can upgrade and downgrade by no more than three releases at a time. This policy
remains unchanged.

For more information on EEOL releases and to review a list of EEOL releases, see
http://www.juniper.net/support/eol/junos.html "

That URL, however, gives no data on between what EEOL releases the jumps are actually supported.

(But, as you can see, 9.6 is not a EEOL release).

I have a customer that had quite a few boxes of all varieties that they had purchased about two years ago, so it took quite a few of these "discoveries" to find the exact correct upgrade-path.  We even had to do some initial intermediate upgrades using versions that Juniper doesn't even publish any more on some SRX-3600's.  It would be nice if each release posted listed an exact "minumum version required" so that we didn't have to go searching through forums or try everything out in the lab.

Ron