Your server run in XEN kernel with cloudmin 7.7 GPL and you may getting the below error, when you creating new Virtual Machine,


Registering Xen configuration file ..
.. failed : Error: memory_dynamic_max must be less than or equal to memory_static_max Using config file "/xen/newvps.cfg".

Starting up new Xen instance ..
.. failed to start :

PTY PID: 1351
Error: Domain 'newvps' does not exist.

Fetching current status ..
.. status successfully retrieved (Down)

or you may getting an error same when you start the virtual machine manually using below command,
 
#  xm create /xen/newvps.cfg


Using config file "/xen/newvps.cfg".
Error: memory_dynamic_max must be less than or equal to memory_static_max

Solution:

Read the below error message carefully ,

"memory_dynamic_max must be less than or equal to memory_static_max"

you want to be check the memory allocation in configure file for new virtual server : /xen/newvps.cfg

maxmem memory should be grater than virtual machine memory,

memory = 5000
maxmem = 2048
name = 'newvps'
vif = [ 'ip=192.168.0.254,mac=00:16:3e:D9:2A:4E,bridge=xenbr0,rate=5120K' ]
address = '192.168.0.112'
...

the above configure changed to maxmem = 5048

memory = 5000
maxmem = 5048
name = 'newvps'
vif = [ 'ip=192.168.0.254,mac=00:16:3e:D9:2A:4E,bridge=xenbrid0,rate=5120K' ]
address = '192.168.0.112s'
...

Once changes has been done try to start the xen server,
 
#  xm create /xen/newvps.cfg

Using config file "/xen/newvps.cfg".
Started domain newvps (id=12)
# xm list

Name                                        ID   Mem VCPUs      State   Time(s)
Domain-0                                     0  5111    21     r----- 274741.1
newvps                                      12  5000     1     r-----     53.1


For more command about xen refer the URL