I am an experienced engineer, but relatively new to Linux. Perhaps this question may be to technical for the newbee list, however, I thought I would start there. I appologize if this is not the right forum for this level of topic.

I have been working on updating a kernel based on Mandrake 7.1 (2.2.17) to 2.4.17 or 2.4.28 neither of which works. The kernel installs fine and appears to build fine, however, I get the following message each time I attempt to boot the image.

invalid compressed format (err=1)

system halted

The code base that I am working with is based on Mandrake 7.1 and it would be difficult to move to say Mandrake 10.0. Instead, I would like to update the kernel to a later version. I know this can be done because the product uses 2.4.17 as the kernel and all I am trying to do is update the development system to the same kernel level or newer. The code compiles and links fine without any errors until the image is booted. I have searched and seen lots of references to this type of error when installing a new Linux distribution, ether from CD, Floppy or RAM Disk. No reference to this problem with regards to booting from the hard drive or after having rebuilt the kernel. I am using Grub to boot the image. The old image boots fine, but the new one gets the above error. I have painstakingly looked over the .configs from both kernels to try and keep the same configurations.

I don't believe that this has anything to do with the type of drive or controller card. The SCSI driver is suspect as it would be different between the two kernels, however, I would expect that to have nothing to do with the compression format of the file, unless the real problem is a read error or corrupt data and not invalid compressed format.

I am at a loss as to how to proceed. Any help would be greatly appreciated.

I am suspect of the initrd file as the 2.2.17 Kernel had an initrd file while the new one does not. I have tried to generate the initrd file, but this is where I run into problems. It appears that the make modules and make modules_install did not provide a SCSI driver in the /lib/modules text file, so that when I run mkinitrd I get an error something like aic7xxx driver not found.

These problems are likely related but not sure at this point.

Any help would be greatly appreciated. Thanks in advance for any help.

One important thing: you need to upgrade libc to run kernel 2.4 and upgrade to even newer version for 2.6. I recommed to try with latest libc, it should work and you'll have bigger choice of kernels. BUT: upgrading libc main be pain, it's main system library (but 2.2. should still work with it). In case of problems: do backup

Don't know what's the driver there are problems with, but check your new kernel configuration and make sure there's everything you need. If you have problems with initrd, build a kernel not requiring one - build everything you really need into the kernel (but warning here: it has a maximum size).

Thanks for the information. I discovered that the problem was I did not install the kernel source properly. I installed in /usr/src/linux. The README says don't do that. (RTRME) Also I did not do a make mrproper. Once I installed the kernel in my home directory and ran make mrproper, followed by make config, followed by make deps && make bzImage && make modules && make modules_install the kernel booted properly.
It just complains about no initrd image. Now I am on to mkinitrd as this fails to build due to "No module aic7xxx in kernel 2.4.17 found" or something like that. I am now looking at the modules.txt to make sure that I have the modules setup correctly. Thanks again for your information. It got me looking in another place and I found information that got me to the documenation and the readme. I skipped the README because I was working with a Linux Redhat Unleashed book. I will not ignore READMEs again

Thanks again,