Veritas is one of the best solution for concurrent write (Veritas Cluster Volume Manager (CVM)) and it allows up to 128 nodes in a cluster to simultaneously access and manage a set of disks under VxVM control. Alternatively, you can check GPFS (IBM Spectrum Scale) as well, which will support more than 1000 nodes in a cluster. In this article, we’ll show you how to create shared Disk Group (DG), Volume and FileSystem (VxFS) in two node (Active-Active) Veritas Cluster. Prerequisites RDM Disk must be added in shared mode between nodes from Storage. If it’s a VM then it should be added at VMWare ..read more

This is a routine task for Linux/Unix administrator to increase the VxFS filesystem when you are running out of space. It can be done in online safely without any issues. In this scenario, the Disk Group (DG) already has sufficient free space and we will be simple resizing it. Refer the following article if you want to create a Veritas Diskgroup (DG), Volume, and VxFS filesystem in Linux. Step-1: Identifying Filesystem First, identify the filesystem to be increased/extended using the df command. Also, note down the DiskGroup (DG) and Volume name from the below output, which will be used later ..read more

Veritas Cluster (VCS) is the most popular among others because I have seen VCS running on many mission critical systems, especially core banking systems were running on Veritas clusters. In this article, we will show you how to create a Disk Group (DG), Volume and Filesystem using Veritas Volume Manager (VxVM) in Linux. Veritas Volume Manager (VxVM) allows you to easily manage volumes and it improves performance and ensure data availability and integrity. Step-1: Scanning LUNs After the Storage team mapped the new LUN to the host, obtain the LUN id and keep it handy. Use below command to scan ..read more

There are situations where we would be required to move a whole volume group from one system to another system for some requirement. As part of this, it also moves underlying logical volumes (LVM) too. It is very easy and can be done using vgexport and vgimport commands. This article will guide you on how to move or migrate LVM and volume group from one server to another. Let’s move a volume group named ‘server1_data_vg‘ from one system to another, which is currently holding the following LVM ‘/dev/server1_data_vg/lvol1’ and it’s mounted under ‘/data’. Make a Note: Though not necessary, always ..read more

There are situations where a storage device or LUN must be removed from running system without any issue. This happens for a variety of reasons, but most commonly, when the storage team migrates to new storage. In this scenario, the storage LUN was configured as a logical volume disk (LVM) on the system. In this tutorial, we will show you how to remove a storage device (LUN) from a Linux system with six simple steps. Make a note: As a best practice, I would recommend backing up data from the device before removing it from the system. This is necessary if you want to restore the data to an earl ..read more

In some cases, you may need to find a block device mapped against a logical unit number (LUNs) for filesystem (FS) expansion or disaster recovery (DR) activity. Also, this information is required if you want to work with the storage team to troubleshoot or fix a high latency or disk error on a specific block device. Refer the following article to map ASM disks against storage LUNs. This information can be found at the following location. However, you will not find mapping details for multipath LUNs because it shows the name of the multipath device instead of the block devices. ls -ltrh /dev/d ..read more

Disk space on Linux can be expanded by adding a new LUN or resizing an existing LUN on the system. In most cases, the online resizing of the multipath device involves two things: resizing the the logical unit (LUN) size and reflecting the size on the corresponding multipath device. In this article, we will show you how to resize an online multipath device on Linux. 1) Identify the multipath device 'mpath22' to be resized using the ‘multipath -ll’ command. multipath -ll | grep 'mpath22' 2) Request the storage team to increase the LUN size on the SAN as needed. 3) After changing the LUN size o ..read more

In some cases, you may need to find a block device mapped against a logical unit number (LUNs) for filesystem (FS) expansion or disaster recovery (DR) activity. Also, this information is required if you want to work with the storage team to troubleshoot or fix a high latency or disk error on a specific block device. Refer the following article to map ASM disks against storage LUNs. This information can be found at the following location. However, you will not find mapping details for multipath LUNs because it shows the name of the multipath device instead of the block devices. ls -ltrh /dev/d ..read more

In most cases, disk space can be expanded by adding a new LUN to the system. But in some scenario, you may need to resize the existing LUN in order to extend the file system. Extending the file system involves two parts, extending the corresponding logical volume and then growing FS over it. Adding, resizing or deleting the LUN on a Linux system can be done without restarting. In this article, we will show you how to extend the Logical Volume (LVM) by resizing the existing LUN on Linux. Resizing LUN or Disk on Linux Please follow the below procedure for resizing an existing LUN or Disk on Linu ..read more

xfs_repair command repairs corrupt or damaged XFS filesystems. It’s highly scalable, high-performance and is designed to effectively repair even very large file systems with many inodes. Unlike other Linux file systems, xfs_repair does not run at boot time, even if the XFS file system was not cleanly unmounted. It’s 64-bit journaling file system that supports very large files (8 EB) and file systems (16 EB) on a single host. XFS is the default file system for Red Hat Enterprise Linux 7. The file system to be repaired must not be mounted before performing xfs_repair, otherwise the resulting fil ..read more