-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of John R Pierce Sent: Tuesday, August 26, 2014 20:11 To: centos@centos.org Subject: Re: [CentOS] Copy on write loop block driver
On 8/26/2014 5:03 PM, Jason Pyeron wrote:
What am I doing wrong here?
A) you don't create anything in /dev, the driver should be using devfs to create its own devnodes on the fly as needed.
I assumed such, but it did not work.
B) you apparently never loaded the driver. see http://www.atcomputing.nl/Tools/cowloop/loadunload.html
3.2.0.1 says:
root@localhost ~/cowloop-3.2.0.1 # cat RELEASENOTES.3.2.0 This is version 3.2 of the Copy on Write loop driver 'cowloop' by ATComputing in Nijmegen, The Netherlands. Release date: September 2009. ----
Cowloop wil be part of the 2.6.31 kernel. This has lead to some changes in the cowloop utils. Obviously the kernel module has been removed from the distribution, only the utilities remain.
root@localhost ~/cowloop-3.2.0.1 # modprobe cowloop FATAL: Module cowloop not found.
root@localhost ~/cowloop-3.2.0.1 # find | grep loop ./man/man4/cowloop.4 ./doc/cowloop.ps.bz2 ./doc/README.cowloop.doc ./src/cowloop.h
So there is no loop driver compiled from this source, but the docs say it is supposed to be included in
root@localhost ~/cowloop-3.2.0.1 # yum whatprovides *cowloop* Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile No Matches found
root@localhost ~ # rpm -iv kernel-2.6.32-431.el6.src.rpm
It looks like the kernel does not have it set
root@localhost ~/rpmbuild/BUILD # grep -ri cowloop kernel-2.6.32-431.el6/ kernel-2.6.32-431.el6/linux-2.6.32-431.el6.x86_64/temp-i686-debug-final:# CONFIG_COWLOOP is not set kernel-2.6.32-431.el6/linux-2.6.32-431.el6.x86_64/.config.old:# CONFIG_COWLOOP is not set kernel-2.6.32-431.el6/linux-2.6.32-431.el6.x86_64/temp-i686-final:# CONFIG_COWLOOP is not set kernel-2.6.32-431.el6/linux-2.6.32-431.el6.x86_64/config-generic:# CONFIG_COWLOOP is not set
I cannot make this a module:
root@localhost ~/rpmbuild/BUILD/kernel-2.6.32-431.el6/linux-2.6.32-431.el6.x86_64 # make HOSTLD scripts/kconfig/conf scripts/kconfig/conf -s arch/x86/Kconfig .config:1304:warning: symbol value 'm' invalid for BLK_DEV_COW_COMMON # # configuration written to .config #