SELinux File Labeling All files, directories, devices, and processes have a security context (or label) associated with them. For files, this context is stored in the extended attributes of the file system. Problems with SELinux often arise from the file system being mislabeled. If you see an error message containing file_t, that is usually a good indicator that you have a problem with file system labelling. There are several ways to relabel the file system: Create the /.autorelabel file … [Read more...] about Understanding SELinux File Labelling and SELinux Context
How to delete a partition using fdisk
The post list out the steps to delete a disk partition using fdisk command. Please note the procedure to delete a primary and extended partition is same. For the example in the post we are using the disk /dev/sdc and the partition to be deleted is /dev/sdc1. Umount the filesystem Make sure you have umounted the filesystem using the partition to be deleted. To view if the partition is mounted use the below command. # cat /proc/mounts To umount the mount point use the below command. # … [Read more...] about How to delete a partition using fdisk
“mount.nfs: access denied by server while mounting” – how to resolve
Problem Mounting the nfs share from CentOS/RHEL NFS server on a NFS client gives error as shown below: # mount -t nfs x.x.x.x:/share /mnt mount.nfs: access denied by server while mounting x.x.x.x:/share You can try running the mount command with the verbose option to get an detailed error on the issue. # mount -t nfs -vvvv server.example.com:/share /mnt mount.nfs: timeout set for Fri Mar 9 17:56:57 2018 mount.nfs: trying text-based options … [Read more...] about “mount.nfs: access denied by server while mounting” – how to resolve
fdisk: Unable to write /dev/sdg: Bad file descriptor – error while formatting USB disk
Problem While formatting a USB disk which was mounted in write-protected mode we are getting the below error: fdisk: Unable to write /dev/sdg: Bad file descriptor Solution 1. The disk in this example is /dev/sxx. Disable read-only mode on the USB disk first. Make sure hdparm is installed, then run the following command: # hdparm -r0 /dev/sxx 2. Make sure the util-linux package is installed, and then wipe out the file system. # wipefs --all /dev/sxx --force 3. Make a new parttion on … [Read more...] about fdisk: Unable to write /dev/sdg: Bad file descriptor – error while formatting USB disk
Linux OS Service ‘nfslock’
The Network File System (NFS) is a client/server protocol that allows a directory hierarchy located on an NFS server to be mounted on one or more NFS clients. Once this is done, the NFS client can transparently access the NFS server files. The NFS server-side daemons arbitrate simultaneous access by multiple clients. Entire files, or individual regions of files, can be locked by a client to avoid race conditions caused by concurrent modification or by viewing partial updates. The nfslock … [Read more...] about Linux OS Service ‘nfslock’
Linux File/Directory Permissions cheat sheet
Here is a short note/cheat sheet for Linux directory and file permissions. The table below gives numbers for all permission types of a File/Directory. Number Permission Type Symbol 0 No Permission --- 1 Execute --x 2 Write -w- 3 Execute + Write -wx 4 Read r-- 5 Read + Execute … [Read more...] about Linux File/Directory Permissions cheat sheet