Upgrading a C3750G with insufficient flash

[bvj197222]

We have several WS-C3750G-24PS running on 12.2(50)SE3. I need to upgrade the switches with 15.2.4E10(MD). First I need to upgrade to 12.2(53)SE2 as that is the supported by minimum Cisco IOS release. The only IOS-sw available is the 12.2.55-SE13 (MD) so I'll upgrade to that one first. 

My issue is the memory;

SWITCH# sh flash:

Directory of flash:/

3 -rwx 4035 Oct 28 2019 12:29:01 +01:00 private-config.text
4 -rwx 5144 Mar 1 1993 01:01:24 +01:00 multiple-fs
5 -rwx 1096 May 4 2016 11:27:04 +02:00 vlan.dat
6 -rwx 16483 Oct 28 2019 12:29:01 +01:00 config.text
8 drwx 192 Sep 14 2009 15:48:39 +02:00 c3750-ipservicesk9-mz.122-50.SE3

32514048 bytes total (17469952 bytes free)

SWITCH#dir
Directory of flash:/c3750-ipservicesk9-mz.122-50.SE3/

9 -rwx 12239852 Sep 14 2009 15:47:31 +02:00 c3750-ipservicesk9-mz.122-50.SE3.bin
10 drwx 4608 Sep 14 2009 15:48:39 +02:00 html
429 -rwx 676 Sep 14 2009 15:48:39 +02:00 info

17 MB is enough for the 12.2.55, which is 14 MB. However, the 15.2-software is 24 mb (bin-file) or 30 mb (tar-file). How do you suggest I go about to do this. If I delete the .bin-file in flash I get additional 12 MB, a total of 29 mb. That's enough to install the .bin-file which is 24 mb. Then I could upgrade using this procedure;

#copy tftp: flash:  (copy the bin-file to the switch)

#boot system switch all flash:/image_name.bin

#sh boot (verify boot procedure)

#reload

For stacked switches I need to copy the bin-file locally from flash1: to flash2: 

I know it's considered risky to delete the running .bin-file, which is why I'd like to put out this question and get some advice from the experts.

[marce1000]

 - This thread may confirm the need to delete the running image, however copy the startup-config to external storage too, in case you need to rebuild the switch from scratch:

         https://community.cisco.com/t5/switching/3750-switch-ios-upgrade-issues/td-p/1767445

 M.

[Leo Laohoo]

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@bvj197222 wrote:

#copy tftp: flash:  (copy the bin-file to the switch)

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The copying of the BIN file to the switch is very dangerous.  Tell me this:  

1.  How do you know you're copying a BIN file meant for a 3750G? 

2.  How do you know after copying, the BIN file is not corrupt at all? 

Have you tried using this:  

archive download-sw /over /image tftp://<TFTP_IP_ADDRESS>/<IOS_FILENAME.TAR>

The command instructs the system to do the following: 

1.  Overwrite the old IOS;

2.  Unpack only the BIN file but do not unpack the HTML files; 

3.  Change the boot variable string; &

4.  After the unpacking, run a CRC check to verify the BIN file is not corrupt

[bvj197222]

The IOS-file is available as .bin and .tar, so the file should be the right one. After copying it I can use the #verify /md5 flash:filexxx.bin to make sure it wasn't corrupted during transfer. I agree that the .tar-file would be the best option, but without enough flash I'd get an 'insufficient memory'-error when trying to upgrade.

[Leo Laohoo]

Use the "archive download-sw /over /image" and post the complete output. I want to see the error message.

[andrew.butterworth]

The 15.2x IOS versions won't work on the 3750/3750G series.  It is for 3750X series switches only.

Depending on the 3750 hardware model you can only upgrade to either 12.2(55)SE12 or 15.0(2)SE11 as they have either 16GB or 32GB FLASH:

The release notes for 15.0(2)SE and later state this:

Not all Catalyst 3750 and 3560 switches can run this release. These models are not supported in Cisco IOS Release 12.2(58)SE1 and later: WS-C3560-24TS, WS-C3560-24PS. WS-C3560-48PS, WS-C3560-48TS, WS-C3750-24PS, WS-C3750-24TS, WS-C3750-48PS, WS-C3750-48TS, WS-3750G-24T, WS-C3750G-12S, WS-C3750G-24TS, WS-C3750G-16TD. For ongoing maintenance rebuilds for these models, use Cisco IOS Release 12.2(55)SE and later (SE1, SE2, and so on).

You should be able to install 15.0(2)SE11 on that particular switch as it will have 32GB FLASH but don't attempt to load the 3750X series images as they won't work.

These are all EoL switches though so don't appear in software downloads anymore.  However the 3750V2 switches are and the IOS is the same.

Andy