Couldn’t find any article that explained step by step how to resize the main disks volume in a CentOS 7 vm. In my example I started witha single disk of 8GB and expanded to 20GB. I have two partitions on disk sda
sda1 type Linux for boot
sda2 type Linux LVM for the remaining logical volumes
Space utilisation as following:
[root@vcd-c1-s1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 3.9G 0 3.9G 0% /dev
tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs 3.9G 8.8M 3.9G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/mapper/centos-root 6.2G 1.9G 4.4G 31% /
/dev/sda1 1014M 179M 836M 18% /boot
tmpfs 783M 0 783M 0% /run/user/0
We basically need to: Continue reading “CentOS 7 XFS disk resizing” »
Device Mapper Multipathing (DM-Multipath) is a native multipathing in Linux, Device Mapper Multipathing (DM-Multipath) can be used for Redundancy and to Improve the Performance. It aggregates or combines the multiple I/O paths between Servers and Storage, so it creates a single device at the OS Level.
For example, Lets say a server with two HBA card attached to a storage controller with single ports on each HBA cards. One lun assigned to the single server via two wwn number of both cards. So OS detects two devices: /dev/sdb and /dev/sdc. Once we installed the Device Mapper Multipathing. DM-Multipath creates a single device with a unique WWID that reroutes I/O to those four underlying devices according to the multipath configuration. So when there is a failure with any of this I/O paths, Data can be accessible using the available I/O Path.
Install the Device Mapper Multipath package.
Verify the device-mapper-multipath package has been installed or not.
[root@linux1 ~]# rpm -q device-mapper-multipath
If it is not installed, Install the Device Mapper Multipath package using yum to avoid dependencies issue. if yum is not configured, please refer the link Yum Configuration on Linux.
[root@linux1 ~]# yum -y install device-mapper-multipath
Basic Configuration of Linux Device Mapper Multipathing
Configuration file is /etc/multipath.conf file, take a backup of it. Edit the configuration file to ensure you have the following entries uncommented out. Continue reading “Add Multipath and connect to XFS system” »