virsh is the interface or command for managing the virtual machines based on the KVM hypervisor. On virsh interface virtual machines are identified by their domain names, so virsh is generally used to list current domains, to create, pause & shutdown domains. Virsh comes under GNU Lesser General Public License and supports Xen, QEmu, KVM, […]
RHV
How RHEVM Monitor Storage Health
This post will illustrate how RHEVM monitors storage health in detail. Monitor Storage Pool Manager Health The Storage Pool Manager (SPM) is a management role assigned to one of the hosts in a data center enabling it to manage the storage domains of the data center. RHEVM check SPM availability and metadata integrity at every […]
How does Sanlock Work in RedHat Virtualization
In RHV, KVM Host uses Sanlock to detect the connectivity with Storage domain. When Sanlock enables, it will open wdmd daemon(watchdog multiplexing daemon) and send keepalive with certain heartbeat. sanlock IO to storage does not complete within a fixed time, sanlock stop sending keepalive to wdmd. When it is timeout,the wdmd daemon controlling /dev/watchdog will […]
RHV – Understanding “Resilience Policy” for VM live migration
In RHV web portal, Select “Compute” -> “Cluster” -> Select one cluster object -> click “Edit” -> click “Migration Policy”, there is a control called “Resilience Policy”, this note explains how “Resilience Policy” controls VM live migration during an outage. Basically “Resilience Policy” controls how virtual machines running on the host in “Non-operational” state in […]
How To Change Engine Database Password for RHVM Engine
This post illustrates steps to change engine database password for RHVM engine. 1. Before modification, you can run below commands to check the current ENGINE_DB_PASSWORD for RHEVM engine interacting with the engine database. By default, ENGINE_DB_PASSWORD is a random string which is auto-generated by engine-config during the setup process. The ENGINE_DB_PASSWORD is used by below […]
How to Reset Unknown VM in RHV Engine Database
On AdminPortal, you see that the VM status becomes unknown with a black question mark and all operations become grey and no operation can be done on this VM as follows: This post will show you how to reset state of vm in the engine databse and run the VM again. 1. Follow the below […]
How to Backup And Restore The RHEV Manager Engine
Backup Use the engine-backup command to create a backup. The usage and mandatory arguments with the command are listed below: 1. –mode=MODE where MODE -> for collecting backup it should be set to “backup” 2. –scope=SCOPE where SCOPE -> can be set to “all” or “files” or “db” or “dwhdb” if set to “all” everything […]
Useful RHV Engine PostgreSQL Database Queries
This post will explain some practical psql commands and describe how to run the PostgreSQL queries from the command line to get useful information from the engine database. Connect To The ‘Postgres’ Database From The Command Line To connect to the ‘Postgres’ database: # su – postgres Last login: Thu Apr 30 20:25:36 AEST 2020 […]
RHV – How to shutdown a VM from AdminPortal
This post will tell the process of shutdown a VM when you press the ‘shutdown’ button from AdminPortal. Here is the detailed process of a VM shutdown: 1. On AdminPortal, click ‘shutdown’ button on a VM. 2. RHV engine sends the “PoweringDown” to vdsm. 3. vdsm talks with libvirt to release VM resources. The below […]
RHV – What is the process of LV Extension
Logical volume extension is used to provide additional storage and facilitate the continued operations of the virtual machine. This article will tell the process of Qcow2 type logical volume extension with thin provision allocation. Here is the process of LV extension: 1. When the virtual disk image is stored on storage with Qcow2 format, Qemu […]