Technote (FAQ)
Question
What
happens if VMs (LPARs) managed by PowerVC are altered directly via
HMC or novalink?
Cause
PowerVC
is built on OpenStack. OpenStack is assumed to be the single
operator/manager for all resources under control of OpenStack.
Answer
IBM
PowerVC infocenter covers in general terms here:
https://www.ibm.com/support/knowledgecenter/en/SSXK2N_1.3.2/com.ibm.powervc.standard.help.doc/powervc_limitations_hmc.html
Specific examples of problems include:
1.) LPM a LPAR using HMC to another Frame
Outcome: PowerVC will now report the VM in error on the original frame.
If the new location of the VM is also managed by PowerVC the VM will NOT report on that frame from PowerVC.
Solution:
Unmanage VM ( from PowerVC UI --> click on VMs icon --> select Error VM --> click on Unmanage)
2.) LPAR is "resized" from HMC by adding storage (LUN) to the LPAR
Outcome: Now PowerVC is not aware of that storage, (it will report OK). Future operations such as SRR or LPM will result in the VM being moved WITHOUT the LUN(s) added via the HMC.
Solution:
Manually reattach the LUN, then unmanage the HOST from PowerVC and remanage to get correct details of VM.
3.) Storage is altered on SAN - Relocating disk or enabling vendor storage attributes not supported by PowerVC (any direct alteration of LUNs).
Outcome: This will cause PowerVC to report the VM in critical error status, unable to power on/off or LPM the VM.
Solution: Unmanage the Host and re-manage to "discover" the VM with correct storage state.
4.) Network (IP) management changes by direct OS or management from outside PowerVC.
Outcome: Again the VM will report "OK" until PowerVC attempts a management operation involving the assigned IP address or another VM is deployed using the IP now locked by this first VM unknown to PowerVC.
Solution:
"Unmanaging" the hosts from PowerVC as recover may not be possible in all situations if the VMs managed are not reachable (re-install would be required)
Note: unmanaging the hosts from PowerVC will "free" the locked IPs in PowerVC IP pools if used.
These are just a few common examples. any external management can/will lead to PowerVC failure
Specific examples of problems include:
1.) LPM a LPAR using HMC to another Frame
Outcome: PowerVC will now report the VM in error on the original frame.
If the new location of the VM is also managed by PowerVC the VM will NOT report on that frame from PowerVC.
Solution:
Unmanage VM ( from PowerVC UI --> click on VMs icon --> select Error VM --> click on Unmanage)
2.) LPAR is "resized" from HMC by adding storage (LUN) to the LPAR
Outcome: Now PowerVC is not aware of that storage, (it will report OK). Future operations such as SRR or LPM will result in the VM being moved WITHOUT the LUN(s) added via the HMC.
Solution:
Manually reattach the LUN, then unmanage the HOST from PowerVC and remanage to get correct details of VM.
3.) Storage is altered on SAN - Relocating disk or enabling vendor storage attributes not supported by PowerVC (any direct alteration of LUNs).
Outcome: This will cause PowerVC to report the VM in critical error status, unable to power on/off or LPM the VM.
Solution: Unmanage the Host and re-manage to "discover" the VM with correct storage state.
4.) Network (IP) management changes by direct OS or management from outside PowerVC.
Outcome: Again the VM will report "OK" until PowerVC attempts a management operation involving the assigned IP address or another VM is deployed using the IP now locked by this first VM unknown to PowerVC.
Solution:
"Unmanaging" the hosts from PowerVC as recover may not be possible in all situations if the VMs managed are not reachable (re-install would be required)
Note: unmanaging the hosts from PowerVC will "free" the locked IPs in PowerVC IP pools if used.
These are just a few common examples. any external management can/will lead to PowerVC failure
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