OtisUsenet wrote:
> Allen Kistler wrote:
>> OtisUsenet wrote:
>>> I've got 2 nearly identical servers with kernels compiled from the same
>>> config, yet their initrd files drastically differ in size:
>>>
>>> ServerA:
>>> 1045276 Sep 9 21:30 initrd-2.6.15.4.img-HT
>>> 1053495 May 11 2005 initrd-2.6.9-1.667.img
>>> 1041351 May 11 2005 initrd-2.6.9-1.667smp.img
>>>
>>> ServerB:
>>> 504485 Sep 9 21:29 initrd-2.6.15.4.img-HT
>>> 504107 Apr 11 2005 initrd-2.6.9-1.667.img
>>> 493803 Apr 11 2005 initrd-2.6.9-1.667smp.img
>>>
>>>
>>> Would anyone have any ideas what could cause this?
>>>
>>> More importantly, does this have any effect on kernel performance?
>>> (I skimmed
>>> http://www.tldp.org/LDP/Linux-Filesy...ml/initrd.html and
>>> think that the answer is "no", but I'm like to double-check that.)
>> I can't think offhand of any reason why the sizes should be so
>> different, but you can check on your own what's in the initrds.
>>
>> gzip -cd /path/initrdfile | cpio -idm
>>
>> will extract the contents of the initrds, then you can compare them.
>
> Thanks for this tip, I didn't realize I could do this, but it makes
> sense.
> After uncompressing the two initrd's, and doing a diff -r on them, I
> got only this:
>
> [snip]
>
> Is it possible that the difference in this handful of modules is making
> one initrd double the other one (500KB vs. 1MB)?
>
> Perhaps it is:
> [snip]
>
> Does it make sense to look at the sizes of modules and relate those
> sizes to the size of the initrd?

The fact that the contents of your initrds are so very different is a
major indication that your "nearly identical servers" are hardly
anything close to identical. I don't think you really need to look much
beyond that for explanation.

Otherwise, the sizes of the things in the initrds is definitely going to
affect the the sizes of the initrds.