Can you share (sanitized/redacted) outputs of these commands:
show redudancy show flash show version
to correctly understand your current redudancy configuration/status?
I'm not an HPE Employee
Hi, since the redudancy configured/current modes both report "Warm Standby" redundancy mode (and not the other "NonStop Switching" redundancy mode) it means that your Standby MM (which is/was the failed MM2) should have booted up to a certain point, synced basic files (like config and security) and only then it should have finished the booting process only in case the actual Active MM - which was/is the MM1 - module failed (that's the case when the Standby MM is clearly correctly working and it doesn't receive hearbeat from the Active MM) or only if you performed a manual switchover.
That's to say that once you insert the replacement MM by hotswapping it into MM2 slot no switchover (from Active MM/MM1 to Standby MM/MM2) will happen at least since the actual Active MM/MM1 is correctly working or at least since you issue a redundancy switchover command (or do MM Reset/Shutdown on Active MM, as example).
Based on that what will happen once you hotswap the new MM into MM2?
When you hotswap the MM2 while there is an Active MM (your MM1) already booted up, the newly hotswapped MM (the new MM2) becomes the Standby MM as expected.
No negotiations are needed as to which module becomes the Active MM because (and until) there is already a functioning Active MM...however some conditions must be met to determine if the newly hotswapped MM can become a Standby MM:
- The hotswapped MM clearly must pass its boot selftest.
- The management module redundancy is not administratively disabled (issuing a no redundancy management-module command, if the Active MM's config file has redundancy administratively disabled then the newly hotswapped MM goes into "Offline" mode).
In "Warm Standby" redundancy mode, as opposed to "NonStop Switching" redundancy mode, the Standby MM will only partially boot as described above and heartbeats start to be exchanged with the Active MM.
Considering that your Active MM has primary and secondary flash images already both equal to K.15.18.0013, eventually software mismatch can happen if the newly hotswapped MM has different software image versions preloaded (the difference is always between primay/secondary software images on the new MM2 you're hotswapping - as future Standby MM - and those used on the actual Active MM / MM1 used by your switch to boot from), the switch should manage that software mismatch automatically as described here (see the "Software version mismatch between active and hotswapped module" paragraph).
I'm not an HPE Employee
@IOI-655321 wrote:Hi parnassus,
Thanks vey much that makes sense, and good to know more about the 'Warm Standby' vesus 'NonStop' modes
I intend to remove the Compact Flash card from the failed module and insert it into the replacement, then swap out the modules. Hopefully that will keep the software versions the same.
So long as there is no impact, i.e. the switch rebooting or similar it should be a zero downtime change?
Thnaks again
Exchanging the Compact Flash could be a way to avoid software versions mismatches between what there is on the Active MM/MM1 and the next Standby MM/MM2...clearly if the existing CF status is OK.
In any case I'm pretty confident that will be Zero Downtime.
I'm not an HPE Employee