How to add mount option nodev for /var/lib/nfs/rpc_pipefs partition on RHEL 7

Recently latest vulnerability found on Red Hat Enterprise Linux 7 system during audit by security team. According to audit team, 'nodev' need to be an added mount for /var/lib/nfs/rpc_pipefs partition. 

To resolve this vulnerability please perform the below steps as suggested by Red Hat.

1. We need to create Drop-In directory for var-lib-nfs-rpc_pipefs.mount

[root@redhat001:~]# mkdir -p /etc/systemd/system/var-lib-nfs-rpc_pipefs.mount.d/

2. Now we need to create configuration file adding this mount point

[root@redhat001:~]# printf '[Mount]\nOptions=nodev\n' > /etc/systemd/system/var-lib-nfs-rpc_pipefs.mount.d/99-nodev.conf

3. Please take a reload of daemon service

[root@redhat001:~]# systemctl daemon-reload

now please take a restart of mount services.

[root@redhat001:~]# systemctl restart var-lib-nfs-rpc_pipefs.mount

Using above steps we can add mount option nodev for /var/lib/nfs/rpc_pipefs parition on rhel7. To verify the mount point you can run the below command

[root@redhat001:~]#grep rpc /proc/self/mounts

sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw,nodev,relatime 0 0

If you see above output, nodev option has been successfully mount. This is straight steps need to follow to resolve such vulnerability. 

Can not remove Logical Volume, message "Logical volume contains a filesystem in use"

In my local machine, I have multiple logical volume. When I try to remove below logical volume, getting below error.

[root@redhat001:~]# lvremove /dev/mapper/system-lv_redhat

Logical volume /dev/mapper/system-lv_redhat contains a filesystem in use.

To remove this logical volume in redhat linux system, please follow the below methods. 

1. Please check if any logical volume mounted on your system. To check this you can simply use "mount" command with grep option.

[root@redhat001:~]# mount | grep /dev/mapper/system-lv_redhat

Above command will provide you information if logical system is mount or not.  If you found, file system is mount, then please umount it first, remove entry from /etc/fstab then try to remove logical volume.

2. In case no logical volume mounted but still you are not able to remove logical volume then you need to check this method if any file is open or any active process using by this logical volume. To check this please run the below command. 

[root@redhat001:~]# lsof | grep /dev/mapper/system-lv_redhat

or 

[root@redhat001:~]#ps -ef | grep /dev/mapper/system-lv_redhat

Using first command you can find if any file is open at system end and it is use by this logical volume, so please check this and close files.

Second command use when you get any process using by this logical volume. please kill the particular process. If process use by root file system, I would suggest instead of killing the process, please stop any application if running and reboot the server, so it would automatically kill your process.

3. You can deactivate logical volume and remove it

[root@redhat001:~]# lvchange -an /dev/mapper/system-lv_redhat

[root@redhat001:~]#lvs

[root@redhat001:~]#lvremove -f  /dev/mapper/system-lv_redhat

Please deactivate logical volume using lvchange command and run lvs to verify that logical volume deactivate or not. 

Hope using above three methods you can resolve this error. In case of any query, please drop a comment on this article. 

mount: wrong fs type, bad option, bad superblock on /dev/mapper/system-lv_redhat error and solution

When we mount any file system or disk on redhat linux server, we have received below error message some times. 

[root@redhat001:~]# mount /redhat

mount: wrong fs type, bad option, bad superblock on /dev/mapper/system-lv_redhat

In above, /redhat is mount point and /dev/mapper/system-lv_redhat is device mapper name for this file system. 

system is volume group and lv_redhat is logical volume.

To resolve this issue, you need to check below points and performed action.

1. Check /etc/fstab entry, file system type (eg. xfs, ext4 etc.) should be correct. 

2. Check data integrity or the filesystem type using below command:

[root@redhat001:~]# file -sL /dev/mapper/system-lv_redhat

/dev/mapper/system-lv_redhat: SGI XFS filesystem data (blksz 4096, inosz 512, v2 dirs)

The output of the above command shows that filesystem type is XFS

3. Check filesystem type mentioned in /etc/fstab:

[root@redhat001:~]#cat /etc/fstab

/dev/mapper/system-lv_redhat /redhat xfs defaults 1 2

4. If bad superblock found on the server, we need to repair file system. 

To check bad superblock you can run "e2fsck" and "tune2fs"  for ext formatted file system and "xfs_repair" for xfs file system. 

For above example, file system is xfs type , so please run the below command to repair file system.

Before doing this, please ensure, you have backup of this file system in tape library or any other backup solution. 

[root@redhat001:~]# xfs_repair  /dev/mapper/system-lv_redhat

It will take time to repair file system, also depend upon file system size. If file system size bigger, the repairing process will take long time.