The addition of a new host server installed with the free XenServer Enterprise 5.5 hypervisor, even if it can be trivial using the XenCenter graphical interface
It can easily generate errors even if the host machines are practically the same, of the same brand and model, this is because to allow a painless XenMotion migration, the compatibility between the processors and the installed software must be as homogeneous as possible.
The generic errors that the graphical interface (XenCenter) generally proposes are
The hosts in this pool are not homogeneous.reason. Software Version Differs
The hosts in this pool are not homogeneous.reason. cpu differ
In the case of the software it could be that on one of the two hosts the extra Linux pack has not been installed, instead in the second case, it is the case to go and check the versions of the CPUs of the two hosts, looking at the file /proc/cpuinfo, we could find some difference in the model or flags or generally just trivial differences in the MHz cpu, Below is an example of the output
Processor : 0
vendor_id : AuthenticAMD
CPU Family : 15
Model : 75
model name : AMD Athlon(tm) 64 X2 Dual Core Processor 4200+
Stepping : 2
CPU MHz : 2204.612
cache size : 512 KB
fdiv_bug : No
hlt_bug : No
f00f_bug : no
coma_bug : No
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
Flags : FPU de tsc MSR PAE CX8 apic mtrr cmov pat clflush mmx fxsr sse sse2$
Bogomips : 4410.18
In case we find ourselves with obvious differences, it is not recommended to add the new host in the pool, but if we really want to insist, we need to maneuver from the shell and no longer from the GUI.
Let’s connect in SSH or in console to the new host server and type the following command
xe pool-join master-address=MASTERIP master-username=root master-password=PASSWORD force=true
A few moments of synchronization of the master database to the new host and we added a new resource to our pool
