Veritas Volume Manager (VxVM) comes with DMP (Dynamic MultiPathing) support. DMP allows VxVM to load-balance IOs across multiple controllers, offline paths when failures are detected, and dynamically disable paths when performing maintenance on a specific controller or path (e.g., ugprading a SAN switch or hot swapping an HBA). The process of manually disabling a path [...]
When mirrors and RAID5 devices are created with Veritas Volume Manager, the volume contents need to be synchronized to an initial consistent state (e.g., parity and mirrors need to be synchronized). Veritas assigns a unique task id to each operation, and allows tasks to be monitored and displayed with the vxtask(1m) utility: $ vxtask list [...]
Veritas Volume Manager comes with a wide variety of command line utilities, which can be used to create, delete and maintain Veritas objects. When operations are performed with the CLI and no disk group is passed to the “-g” (disk group to use) option, the command will default to using the value assigned to defaultdg. [...]
Veritas uses disk group configuration records to store subdisk, plex, volume, and device configuration data. The configuration records get written to the private region of specific devices in each disk group, and are described in the vxinfo(1m) manual page: A disk group configuration is a small database that contains all volume, plex, subdisk, and disk [...]
I was approached by a colleague last week to investigate a problem with Veritas Volume Manager simultaneously importing a disk group on two different nodes (this is ok if your using CVM, but we weren’t). As you can imagine, this is a BAD thing, and can lead to chaos and data corruption (depending on what [...]
In addition to providing volume management capabilities, the Veritas volume manager can manage multiple paths to a disk device. This allows I/O to be load-balanced across multiple paths, and ensures that I/O is transparently routed around failed paths. To print path information for a specific disk, you can use the “vxdisk” or “vxdmpadm” utilities: $ [...]
