upgrading the IOS on a stack of two 3750's

[nouman_nabi]

Hi,

I have recently tried upgrading the IOS on a stack of two 3750's. Once I had set the boot path and then reloaded the switch it took 30 minutes to come back online. The documentation I was following was

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_example09186a00804799d7.shtml "3750 Series Switch Stack IOS Upgrade - Manual (.bin image)

I was just wondering if  this is expected behaviour for the 3750 model .?.

Thanks

Nomi

[Reza Sharifi]

Hi,

30 Minutes to reboot is pretty long.  Usually a tar file is used when switches are stacked.  This way you don't have to load every single switch manually.

Reza

[nouman_nabi]

Hi Reza,

Still I am not clear about the issue I am planing to upgrade other switch so these will take same 30 min ?

Thanks

Nomi

[hobbe]

Hi

Yes, no and it depends.

As always a strait answer is not easy to get.

You are upgrading a 3750. depending on what IOS it has today and what you want it to have tomorow the upgrade will include microcodes.

if the upgrade contains microcode it can take some time to do the upgrade.

I just downgraded a 3750x to make it fit in a stack and that took about 40 minutes due to microcode.

so yes a 3750 can take 30 minutes to upgrade.

I never do the .tar file since I do not want the http code lying around on the switch, I do not want to use it so for me there is no reason to have it.

so yes the stack will take about 30 minutes to comeback.

this is one reason why one needs to have a spare switch just to test stuff. now you know how long it will take to do the upgrade / switch and since you do the upgrade on all at the same time it will take aprox 30 minutes.

Dont forget to make shure you have backups of the config before you start.

Good luck

HTH

[Leo Laohoo]

It depends on what IOS you are upgrading to.  Starting from 12.2(50) and later, this version will cause your appliance to boot twice.  This is just a one-time event only.  The first time is caused after the appliance's bootstrap gets upgraded.  Once the upgrade is complete the appliance will reboot to load the new IOS.

Starting with 12.2(55) and later a microcode is added.  This can take a heart-stopping 30-45 minutes (depending on the number of ports your switch has).  Again, this is just a one-time event only.