RHV

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

Qemu Guest Agent has many features like shutdown/restart VM guest and also provides information about the VM guest. You can see basic information which is provided by qemu-guest-agent in Adminportal ( Compute –> Virtual Machines –> Click the VM –> Guest Info ). This post will list the essential features that Qemu Guest Agent provides. […]