[Condor-devel] Is VM_MAX_NUMBER a redundant macro?

[Rob <spamrefuse@xxxxxxxxx>]

Hi,

I'm using Condor 7.2.4.

While I was trying to configure the VM macros in the condor config file,
on my Windows XP pool PCs, I encountered a strange problem.
Maybe this devel list is more appropriate to bring this up.

I ran into this problem when trying to set in the condor_config file the
macros VM_MAX_NUMBER and VM_MEMORY, using the hardware
macros $(NUM_CPUS) and $(MEMORY).

This seemed to work for VM_MAX_NUMBER, but not for VM_MEMORY.
However, digging a little deeper, it seems that setting VM_MAX_NUMBER
to just about any value, doesn't affect condor at all.......

Let me explain this with the following examples:

----------
The default setting for this macro is  VM_MAX_NUMBER = $(NUM_CPUS)
If I set this EXPLICITLY in the condor_config file and then query its value,
I get this:

     C:\condor\bin> condor_config_val.exe -verbose VM_MAX_NUMBER
     Not defined: VM_MAX_NUMBER

----------
If I set it to a specific number, e.g:   VM_MAX_NUMBER = 2
I get this:

     C:\condor\bin> condor_config_val.exe -verbose VM_MAX_NUMBER
     VM_MAX_NUMBER: 2
          Defined in 'C:\condor\condor_config', line 2171

----------
If I set it to a wrong value, e.g.  VM_MAX_NUMBER = "what do I care"
I get this (without any error message in the log files!)

     C:\condor\bin> condor_config_val.exe -verbose VM_MAX_NUMBER
     VM_MAX_NUMBER: "what do I care"
          Defined in 'C:\condor\condor_config', line 2171


The absence of an error message in the last example, tells me that
condor doesn't care at all about the value of VM_MAX_NUMBER.
Also, in the StartLog there's mentioning of the VM settings, but nothing
about VM_MAX_NUMBER:

VM_GAHP_VERSION = "0.0.1"
VM_Type = "vmware"
VM_Version = "server1.0"
VM_Memory = 512
VM_Networking = TRUE
VM_Networking_Types = "nat,bridge"
7/11 14:09:35 
7/11 14:09:35 VMType('vmware') is supported
7/11 14:09:35 The maximum available memory for vm universe is set to 512 MB
7/11 14:09:35 VM networking is enabled
7/11 14:09:35 Supported networking types are nat,bridge
7/11 14:09:36 New machine resource allocated



Hence my humble conclusion:

Although the explanation in the condor_config file suggests that the macro
$(NUM_CPUS) can be used to set VM_MAX_NUMBER, this is actually not true.
$(NUM_CPUS) is not available at startup time and therefore VM_MAX_NUMBER
becomes by default an empty macro.

The absence of any error message when setting VM_MAX_NUMBER to a wrong
value, tells me that Condor doesn't care what its value is and therefore it doesn't
matter at all what value it has!

Is VM_MAX_NUMBER really a redundant macro?


(All this contrasts to the way VM_MEMORY is dealt with; if set to a wrong value,
 then there are plenty of error messages in the log files and the VM universe
 won't be available.)

Best regards,
Rob.