I'm working with kernel module parameters, and I've found myself a bit confused.
In particular, I'm attempting to enable posix ACL support for XFS file systems. This requires the XFS module to be loaded with the parameter
XFS_POSIX_ACL set to yes. Without it, attempts to set ACL's with "setfacl" result in "Operation not supported" errors.
In a test environment, I ran the command "modprobe -v xfs XFS_POSIX_ACL=y". Despite now knowing that you need to first remove a module before you can set parameters, this command appeared to have worked. After running it, I was successfully able to run "setfacl", set some ACL's and test them with full functionality.
Moving over to production though, it appears - not surprisingly - that simply running "modprobe -v xfs XFS_POSIX_ACL=y" doesn't seem to enable ACL support, likely due to the fact that I haven't unloaded the module first. Running the command produces no output, and attempts to set an ACL result in "Operation not supported" errors.
The problem I'm having, is that after going back to my test environment and attempting to "flip the parameters switch properly," running
modprobe -r xfs followed by "modprobe -v xfs XFS_POSIX_ACL=n" doesn't turn off ACL support. I've run modprobe -r in verbose mode, and the module is in fact unloaded (rmmod /lib/modules/...xfs.ko) , but reloading it with the ACL parameter set to NO has no effect.
Any ideas what I might be doing wrong?
RHEL 4.9, 2.6.9-89
It looks like I have the parameter wrong. Looking at dmesg after running modprobe xfs XFS_POSIX_ACL=N:
xfs: Unknown parameter `XFS_POSIX_ACL' SGI XFS with ACLs, security attributes, large block/inode numbers, no debug enabled SGI XFS Quota Management subsystem
I found the ACL parameter here: http://how-to.wikia.com/wiki/How_to_configure_the_Linux_kernel/fs/xfs
Any idea what the proper parameter might be? modinfo -p xfs returns nothing and I'm having a heck of a time finding it online.