HMC

I have a customer has 3 sites  with 1 HMC per site . They would like to know what is best practice in connecting the 3 site to environment ie the 3rd HMC to manage the environment. 

They currently have 2 private vlans defined and we run DHCP servers on each of these vlans from our existing HMC's. They put 1 port from every FSP on vlan1 and the remaining port on vlan 2, HMC1 then provides IP addresses on vlan1 and HMC2 does the same for vlan2.

Guidance in configuring the 3 rd HMC at site 3 is appreciated .

Hi,

I recall that the official supported configuration is still that one Managed frame can be shown on maximum 2 HMCs, one cannot show frame to 3 HMCs at the same time.

One option for config could be showing frames only to the HMC located on the same site + having one extra (virtual?) HMC, to which one could show frames from all  3 sites.

Br,

tommi

I have a customer has 3 sites  with 1 HMC per site . They would like to know what is best practice in connecting the 3 site to environment ie the 3rd HMC to manage the environment. 

They currently have 2 private vlans defined and we run DHCP servers on each of these vlans from our existing HMC's. They put 1 port from every FSP on vlan1 and the remaining port on vlan 2, HMC1 then provides IP addresses on vlan1 and HMC2 does the same for vlan2.

Guidance in configuring the 3 rd HMC at site 3 is appreciated .

Tommy,

I believe it was 3 HMC's.  I ran into this when migrating from physical HMCs to vHMCs.  

I have 2 Colo's.  I have Power systems at both and a vHMC at both.  Either vHMC can manage both Colo's.  When I tried to bring both the physical and the vHMC online during the migration to support all the racks I hit the wall after the third HMC.

There is a blog on this exact community which discusses pooling which may help.  I've not tried the pooling.

Hi,

I recall that the official supported configuration is still that one Managed frame can be shown on maximum 2 HMCs, one cannot show frame to 3 HMCs at the same time.

One option for config could be showing frames only to the HMC located on the same site + having one extra (virtual?) HMC, to which one could show frames from all  3 sites.

Br,

tommi

I have a customer has 3 sites  with 1 HMC per site . They would like to know what is best practice in connecting the 3 site to environment ie the 3rd HMC to manage the environment. 

They currently have 2 private vlans defined and we run DHCP servers on each of these vlans from our existing HMC's. They put 1 port from every FSP on vlan1 and the remaining port on vlan 2, HMC1 then provides IP addresses on vlan1 and HMC2 does the same for vlan2.

Guidance in configuring the 3 rd HMC at site 3 is appreciated .

Hi Robert,

With pooling U mean Power Enterprise Pools or something else?

Haven't tested this myself either.

But I do recall one time when I had my frame visible on 2 HMCs + accidentally added the frame to 3rd HMC....

We have HMC Home call enabled; so it took less than one hour before I got gentle call from IBM Support "Excuse me, but what the heck U are doing there..? " :D :D :D 

So one can configure 3 HMCs, but it is not officially supported; and if U have home call enabled, it will have this effect too. :)

+ in addition, one needs to remember that if U configure multiple HMCs, ALL HMCs need to be on the SAME major level; U cannot have for example 1 HMC on v10R2 level and the other on v10R3 ...

Br,

tommi

Tommy,

I believe it was 3 HMC's.  I ran into this when migrating from physical HMCs to vHMCs.  

I have 2 Colo's.  I have Power systems at both and a vHMC at both.  Either vHMC can manage both Colo's.  When I tried to bring both the physical and the vHMC online during the migration to support all the racks I hit the wall after the third HMC.

There is a blog on this exact community which discusses pooling which may help.  I've not tried the pooling.

Hi,

I recall that the official supported configuration is still that one Managed frame can be shown on maximum 2 HMCs, one cannot show frame to 3 HMCs at the same time.

One option for config could be showing frames only to the HMC located on the same site + having one extra (virtual?) HMC, to which one could show frames from all  3 sites.

Br,

tommi

I have a customer has 3 sites  with 1 HMC per site . They would like to know what is best practice in connecting the 3 site to environment ie the 3rd HMC to manage the environment. 

They currently have 2 private vlans defined and we run DHCP servers on each of these vlans from our existing HMC's. They put 1 port from every FSP on vlan1 and the remaining port on vlan 2, HMC1 then provides IP addresses on vlan1 and HMC2 does the same for vlan2.

Guidance in configuring the 3 rd HMC at site 3 is appreciated .

Pools:  Not sure.  I only casually glanced at that blog.  What was your interpretation from reading that blog?

3 HMCs:  Granted.  That was only for a migration period.  And only for a few days, until we felt comfortable with vHMC. 

Multiversioning:  Well, we do, but we try to keep it under 24 hours.  We're not going to update both HMCs simultaneously.  a) Process might go very badly.  b)  What if we need to look at a SRC, etc, during the upgrade?

Being able to do a snapshot on vHMC prior to upgrade is a godsend.

Hi Robert,

With pooling U mean Power Enterprise Pools or something else?

Haven't tested this myself either.

But I do recall one time when I had my frame visible on 2 HMCs + accidentally added the frame to 3rd HMC....

We have HMC Home call enabled; so it took less than one hour before I got gentle call from IBM Support "Excuse me, but what the heck U are doing there..? " :D :D :D 

So one can configure 3 HMCs, but it is not officially supported; and if U have home call enabled, it will have this effect too. :)

+ in addition, one needs to remember that if U configure multiple HMCs, ALL HMCs need to be on the SAME major level; U cannot have for example 1 HMC on v10R2 level and the other on v10R3 ...

Br,

tommi

Tommy,

I believe it was 3 HMC's.  I ran into this when migrating from physical HMCs to vHMCs.  

I have 2 Colo's.  I have Power systems at both and a vHMC at both.  Either vHMC can manage both Colo's.  When I tried to bring both the physical and the vHMC online during the migration to support all the racks I hit the wall after the third HMC.

There is a blog on this exact community which discusses pooling which may help.  I've not tried the pooling.

Hi,

I recall that the official supported configuration is still that one Managed frame can be shown on maximum 2 HMCs, one cannot show frame to 3 HMCs at the same time.

One option for config could be showing frames only to the HMC located on the same site + having one extra (virtual?) HMC, to which one could show frames from all  3 sites.

Br,

tommi

I have a customer has 3 sites  with 1 HMC per site . They would like to know what is best practice in connecting the 3 site to environment ie the 3rd HMC to manage the environment. 

They currently have 2 private vlans defined and we run DHCP servers on each of these vlans from our existing HMC's. They put 1 port from every FSP on vlan1 and the remaining port on vlan 2, HMC1 then provides IP addresses on vlan1 and HMC2 does the same for vlan2.

Guidance in configuring the 3 rd HMC at site 3 is appreciated .