Kernel Modules

1. Kernel image
   

   [root@kvm4 ~]# ls /boot
   config-2.6.32-71.el6.x86_64         lost+found
   efi                                 symvers-2.6.32-71.el6.x86_64.gz
   grub                                System.map-2.6.32-71.el6.x86_64
   initramfs-2.6.32-71.el6.x86_64.img  vmlinuz-2.6.32-71.el6.x86_64
   

2. Dynamically loaded modules
   

   [root@kvm4 ~]# find /lib/modules/`uname -r` -name *.ko | more
   /lib/modules/2.6.32-71.el6.x86_64/kernel/fs/ext4/ext4.ko
   /lib/modules/2.6.32-71.el6.x86_64/kernel/fs/jffs2/jffs2.ko
   /lib/modules/2.6.32-71.el6.x86_64/kernel/fs/fuse/cuse.ko
   .....
   

3. The currently loaded modules
   

   [root@kvm4 ~]# lsmod 
   Module                  Size  Used by
   fuse                   66138  0 
   ebtable_nat             1975  0 
   ebtables               18101  1 ebtable_nat
   nfs_acl                 2677  1 nfsd
   auth_rpcgss            44862  1 nfsd
   .....
   

4. Loads the vfat module
   

   [root@kvm4 ~]# lsmod | grep fat
   [root@kvm4 ~]# modprobe vfat
   [root@kvm4 ~]# lsmod | grep fat
   vfat                   10646  0 
   fat                    55086  1 vfat
   

5. Remove the vfat module
   

   [root@kvm4 ~]# modprobe -r vfat
   [root@kvm4 ~]# lsmod | grep fat
   

6. Set module parameters manually
   

   [root@kvm4 ~]# modprobe ecryptfs
   [root@kvm4 ~]# modprobe -r ecryptfs
   [root@kvm4 ~]# cat /var/log/messages | grep ecryptfs
   ## No any message
   
   [root@kvm4 ~]# modinfo ecryptfs
   filename:       /lib/modules/2.6.32-71.el6.x86_64/kernel/fs/ecryptfs/ecryptfs.ko
   license:        GPL
   description:    eCryptfs
   author:         Michael A. Halcrow <mhalcrow@us.ibm.com>
   srcversion:     5A7ADDC1F961E6284ABB2E9
   depends:        
   vermagic:       2.6.32-71.el6.x86_64 SMP mod_unload modversions 
   parm:           ecryptfs_verbosity:Initial verbosity level (0 or 1; defaults to 0, which is Quiet) (int)
   parm:           ecryptfs_message_buf_len:Number of message buffer elements (uint)
   parm:           ecryptfs_message_wait_timeout:Maximum number of seconds that an operation will sleep while waiting for a message response from userspace (long)
   parm:           ecryptfs_number_of_users:An estimate of the number of concurrent users of eCryptfs (uint)
   
   [root@kvm4 ~]# modprobe ecryptfs ecryptfs_verbosity=1
   [root@kvm4 ~]# cat /var/log/messages | grep -i ecryptfs
   Jan  1 13:16:36 kvm4 kernel: eCryptfs verbosity set to 1. Secret values will be written to the syslog!
   
   [root@kvm4 ~]# modprobe -r ecryptfs
   

7. Set module parameters automatically
   

   [root@kvm4 ~]# vi /etc/modprobe.d/local.conf
   options ecryptfs ecryptfs_verbosity=1
   [root@kvm4 ~]# modprobe ecryptfs
   [root@kvm4 ~]# cat /var/log/messages | grep -i ecryptfs
   Jan  1 13:16:36 kvm4 kernel: eCryptfs verbosity set to 1. Secret values will be written to the syslog!
   Jan  1 13:23:55 kvm4 kernel: eCryptfs verbosity set to 1. Secret values will be written to the syslog!
   [root@kvm4 ~]# modprobe -r ecryptfs