ASM disks are the disks used by Oracle Automatic Storage Management software. Veritas Volume Manager (VxVM) co-exists with Oracle ASM disks, by recognizing the disks as the type Oracle ASM. VxVM protects ASM disks from any operations that may overwrite the disk. VxVM classifies and displays the ASM disks as ASM format disks. You cannot initialize an ASM disk, or perform any VxVM operations that may overwrite the disk.
If the disk is claimed as an ASM disk, disk initialization commands fail with an appropriate failure message. The vxdisk init command and the vxdisksetup command fail, even if the force option is specified. The vxprivutil command also fails for disks under ASM control, to prevent any on-disk modification of the ASM device.
If the target disk is under ASM control, any rootability operations that overwrite the target disk fail. A message indicates that the disk is already in use as an ASM disk. The rootability operations include operations to create a VM root image (vxcp_lvmroot command) , create a VM root mirror (vxrootmir command), or restore the LVM root image (vxres_lvmroot command). The vxdestroy_lvmroot command also fails for ASM disks, since the target disk is not under LVM control as expected.
Disks that ASM accessed previously but that no longer belong to an ASM disk group are called FORMER ASM disks. If you remove an ASM disk from ASM control, VxVM labels the disk as a FORMER ASM disk. VxVM enforces the same restrictions for FORMER ASM disks as for ASM disks, to enable ASM to reuse the disk in the future. To use a FORMER ASM disk with VxVM, you must clean the disk of ASM information after you remove the disk from ASM control. If a disk initialization command is issued on a FORMER ASM disk, the command fails. A message indicates that the disk must be cleaned up before the disk can be initialized for use with VxVM.
To remove a FORMER ASM disk from ASM control for use with VxVM
To view the ASM disks
The vxdisk list command displays the disk type as ASM.
# vxdisk list DEVICE TYPE DISK GROUP STATUS Disk_0s2 auto:LVM - - LVM Disk_1 auto:ASM - - ASM EVA4K6K0_0 auto - - online EVA4K6K0_1 auto - - online
The vxdisk classify command classifies and displays ASM disks as Oracle ASM.
# vxdisk -d classify disk=c1t0d5 device: c1t0d5 status: CLASSIFIED type: Oracle ASM groupid: - hostname: - domainid: - centralhost: -
Specify the -f option to the vxdisk classify command, to perform a full scan of the OS devices.
To check if a particular disk is under ASM control
# /etc/vx/bin/vxisasm 3pardata0_2799 3pardata0_2799 ACTIVE
# /etc/vx/bin/vxisasm 3pardata0_2798 3pardata0_2798 FORMER
Alternatively, use the vxisforeign utility to check if the disk is under control of any foreign software like LVM or ASM:
# /etc/vx/bin/vxisforeign 3pardata0_2799 3pardata0_2799 ASM ACTIVE
# /etc/vx/bin/vxisforeign 3pardata0_2798 3pardata0_2798 ASM FORMER