Bug 479333

Summary:	kernel binaries for rawhide really bloated with null bytes
Product:	[Fedora] Fedora	Reporter:	Michal Jaegermann <michal>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	low
Version:	rawhide	CC:	kernel-maint, quintela
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2009-01-13 23:50:42 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Michal Jaegermann 2009-01-08 21:44:04 UTC

Description of problem:

kernel-2.6.29-0.12.rc0.git7.fc11.x86_64.rpm package has a quite reasonable size of 24 Megs but for a disk installation it claims 1035938542 bytes.  You are reading that right.  Something about 1 Gig.

A closer look reveals that this happens because all modules are amply padded with null bytes and 'cp -a --sparse=always ...' on this kernel module tree reduces its size from 997M to 76M (with a kernel after such operation still bootable - not so surprisingly).

The preceding rawhide kernel, i.e. 2.6.29-0.9.rc0.git4.fc11, has a module tree which takes 188M of a disk space.  This is of the same order as with other, relatively recent, rawhide kernels.  Still making those modules sparse drops that size down to 78M which is also significant.

Apart of gobbling a disk space like crazy these "null fattened" modules make kernel installation scripts to run slow as molasses.  Something "interesting" happened with a toolchain?

Comment 1 Michal Jaegermann 2009-01-13 23:50:42 UTC

Recent "2.6.29-0.X.rc1" kernels have module directories of a more reasonable size.  Passing those through 'cpio -pmd --sparse' still slims them down by
roughly 60% but we are not talking gigabytes anymore.