Initialization and/or adding a disk into a DiskGroup is not reflected on KVM Guest machines on other KVM hosts.
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Article ID: 100015555
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Updated On:
Description
Error Message
No errors reported.
Mapping the dmp node with default options - Map the device to the guest using the path using the device path. # virsh attach-disk rhel_guestb /dev/vx/dmp/ams_wms0_279 vdc
- Make the mapping persistent by re-defining the guest. # virsh dumpxml rhel_guestb > /var/tmp/rhel_guestb.xml # virsh define /var/tmp/rhel_guestb.xml
****** snippet of the xml ****
*****************************
[root@rhel_guesta]# vxdisk -o alldgs list DEVICE TYPE DISK GROUP STATUS vdc auto:cdsdisk disk01 dg1 online
[root@rgel-guestb ~]# vxdisk -o alldgs list DEVICE TYPE DISK GROUP STATUS vdc auto:none - - online invalid >>> disk is not seen as initialised disk on other KVM guest in different KVM host
Cause
Mapping a LUN or DMP metanode using "virsh attach-disk kvmguestname" by default enables caching, hence delaying the updates to disks and not reflecting changes on the other KVM guests on different KVM hosts.
Resolution
Map the dmp metanode with the option --cache=none which allows updates to be sent to disks immediately and thus reflecting the changes on other KVM guests on different KVM hosts.
Mapping a LUN or DMP (Dynamic Multi-Pathing) metanode to multiple KVM (Kernel-Based Virtual Machine) guests on different KVM hosts could exhibit the problem of updates to disks (disk label, initialization state, DG info, etc) not reflected on other hosts without rebooting the other KVM host.
