[libvirt] [PATCH] docs: correct setmem text plus expand setmaxmem text

[Matthias Bolte]

2011/1/26 Justin Clift <jclift at redhat.com>:
> On 20/01/2011, at 11:30 PM, Matthias Bolte wrote:
>> 2011/1/19 Justin Clift <jclift at redhat.com>:
>>> This completes the man page updates required for BZ # 622534:
>>>
>>>  https://bugzilla.redhat.com/show_bug.cgi?id=622534
>>
>>> -Change the maximum memory allocation limit in the guest domain. This should
>>> -not change the current memory use. The memory limit is specified in
>>> -kilobytes.
>>> +Change the maximum memory allocation limit for an active guest domain.
>>> +
>>> +Some hypervisors require a larger granularity than kilobytes, and requests
>>> +that are not an even multiple will either be rounded down or rejected.  For
>>> +example, vSphere/ESX rejects the parameter unless the kB argument is evenly
>>> +divisible by 1024 (that is, the kB argument happens to represent megabytes).
>>
>> Actually vSphere/ESX truncates in this case. It rejects in other cases
>> (virsh define).
>>
>> As Dan suggested, I might change this to round up.
>
> With vSphere/ESX, does the virsh "setmaxmem" command work on running guest
> domains, or only inactive ones, or ?
>
> I'd *really* like to update the man page docs around this in the next few days, and
> I'm still not sure what this command is actually doing in the real world.  Heh. ;(

setmaxmem works on inactive guest only.

Thanks for making me test this again, because I found a bug in the ESX
driver, actually in the vSphere API. The API call allows to set max
memory to values that aren't a multiple of 4 megabyte. But such a
virtual machine fails to start as ESX reports a general config fault
for it. The vSphere Client only allows to change this value in 4 mb
steps.

I'll have to fix that.

Matthias