Device mapper

wikipedia:Device mapper

/dev/mapper/
/dev/mapper/control

• ls -lrt /dev/mapper/

• dmsetup ls

vgchange -a|--activate y|n|ay

The block device for the LV is added or removed from the system using device-mapper in the kernel. A symbolic link /dev/VGName/LVName pointing to the device node is also added/removed.

vgchange -a n VG_NAME
 0 logical volume(s) in volume group "VG_NAME" now active
vgchange -a y VG_NAME
 1 logical volume(s) in volume group "VG_NAME" now active

Related terms

• multipath -l (show the current multipath topology from information fetched in sysfs and the device mapper)
• /etc/fstab
• dm verity
• dm mpath

Activities

• Read Configuring Device Mapper Multipath RHEL 8 https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html-single/configuring_device_mapper_multipath/index

Related

• Multipath: remove multipath device unpresented to host

See also

• kpartx
• Device mapper: dmsetup, dmsetup ls, LVM, /dev/mapper/, vgcreate
• Fibre Channel: HBA, multipath-tools, multipath, multipath -ll, /etc/multipath.conf multipathd rescan-scsi-bus.sh powermt Device mapper dmsetup ls,
• LVM: LVM errors LVM scan commands lkvmetad, Add a new disk

scan: pvscan vgscan

LVM: lvs lvmscan lvm fullreport lvmreport lvmconfig lvmdump lvmcheck lvm dumpconfig

Scan: pvs vgs lvs pvscan vgscan

PV: pvcreate pvremove pvscan pvremove pvscan pvs pvchange pvck pvdisplay pvresize

LV: lvdisplay lvcreate lvremove, lvresize, lvextend, lvreduce, lvrename

VG: vgdisplay,vgcreate,vgremove, vgextend, vgreduce, vgscan, vgchange, vgrename, vgcfgbackup, vgcfgrestore, vgimportclone, vgck

Check commands: pvck vgck