The Geek Diary

You can set the mounting options of a filesystem in the file /etc/fstab. For example : # cat /etc/fstab | grep data /dev/mapper/vg01-lv01 /data ext4 defaults 0 2 Viewing mount options of filesystem 1. To see what options a mounted filesystem is utilizing run the mount command can be ran without any arguments. You can also grep for a particular mount point as sometimes (specially if you are using RHEL/CentOS 7) you might get a huge list of system mount points. For example, data in the … [Read more...] about How to find the mounting options of currently mounted filesystem

To mount USB flash drive on any Linux system you will first need to know the disk partition name for the USB drive. Finding the partition name is an easy task. Follow the steps below to find the partition name and mounting it on a directory of your choice. 1. Check for the /var/log/messages file for the messages related to the USB flash drive. As soon as you connect a flash drive you would see messages about it. Oct 6 19:03:32 localhost kernel: usb 1-1: new high-speed USB device number 2 … [Read more...] about How to mount USB flash drive in Linux

The ask here is to merge 2 volume groups with existing LVs and there should be no data loss. For the purpose of this post, we have 2 VGs - vg01 and vg02. Both have one LV each created inside them as shown below : # vgs VG #PV #LV #SN Attr VSize VFree cl 1 2 0 wz--n- 19.00g 0 vg01 1 1 0 wz--n- 20.00g 10.00g vg02 1 1 0 wz--n- 20.00g 10.00g # lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root cl -wi-ao---- … [Read more...] about How to merge 2 volume groups (VGs) into one using vgmerge in LVM

We have already seen how to remove an unused PV from the volume group with vgreduce command. CentOS / RHEL : How to remove unused Physical Volume(PV) from Volume Group (VG) in LVM The vgreduce command shrinks the volume group by removing one or more PVs. But in case if the PV is in use by any of the LV, we have to first move the LVs onto some other free PVs using pvmove and then we can use the vgreduce command as usual to remove the PV. We can then either use these free PVS in another VG … [Read more...] about CentOS / RHEL : How to remove used Physical Volume(PV) from Volume Group (VG) in LVM

Whats is a disk partition Partitioning divides a disk drive into one or more logical disks. Each partition is treated as a separate disk with its own file system. Partition information is stored in a partition table. There are 2 types of partitions that can be created using the fdisk utility : Primary Partitions Extended Partitions Primary Vs extended partitions - The original partitioning scheme for PC hard disks allowed only four partitions, called primary partitions. - To create … [Read more...] about Linux / UNIX : How to create primary partition using fdisk

Once you have created the Physical volumes and volume groups, the next step is to create logical volumes from the space allocated to volume groups. The post discusses few of the most commonly used logical volume related commands and utilities. Creating Logical Volumes Use the lvcreate command to create a new logical volume. This command automatically creates the block device nodes in the /dev directory. The syntax is: # lvcreate [options] --size [size] --name LV_name VG_name The --size … [Read more...] about LVM Configuration : Logical Volume (LV) Operations/Utilities

The next step in implementing LVM after creating the physical volumes or PV, is to assign the physical volumes to an existing or new volume group. Below are the most commonly used VG related operation/utilities. Creating a Volume Group Use the vgcreate command to create a new volume group. Space in a volume group is divided into “extents.” The default physical extent size is 4 MB. The syntax is: # vgcreate [options] volume_group_name physical_volume For example, to create a volume group … [Read more...] about LVM Configuration : Volume Group (VG) Operations/Utilities

The first step in implementing LVM is to create physical volumes. In addition to creating physical volumes, commands exist to display the attributes of physical volumes, remove physical volumes, and perform other functions on physical volumes. Creating Physical Volumes Use the pvcreate command to create physical volumes. The syntax is: # pvcreate [options] device You can initialize multiple disks or partitions for use by LVM in the same command. For example, the following command … [Read more...] about LVM Configuration : Physical Volume (PV) Operations/Utilities

Mutt is known for being a fast and highly configurable mail client, and since it is text-based, it’s ideal for checking email quickly over SSH. Installing mutt mutt can be installed by yum utility as follows. # yum install mutt .... Dependencies Resolved ======================================================================================================================================================================================================== Package … [Read more...] about UNIX / Linux : How to install and configure mutt