[CentOS-virt] Cannot allocate Memory

[Shaun Reitan]

We're using the stock configuration, the dom0 is limited to 1024MB via 
grub.



------ Original Message ------
From: "Pasi Kärkkäinen" <pasik at iki.fi>
To: "Shaun Reitan" <shaun.reitan at ndchost.com>; "Discussion about the 
virtualization on CentOS" <centos-virt at centos.org>
Sent: 6/26/2016 9:30:57 AM
Subject: Re: [CentOS-virt] Cannot allocate Memory

>On Wed, Jun 22, 2016 at 05:45:05PM +0000, Shaun Reitan wrote:
>>     Any of you guys ever seen an issue with Xen 4.4 were xm cannot 
>>create a
>>     guest because of what looks like an issue allocating memory even 
>>though xm
>>     info shows like 5x the amount of free memory needed? We are still
>>     unfortunately still using xm... it's on my list, i know..
>>     We've had this happen on a couple hosts now.  Only way to resolve 
>>seams to
>>     be rebooting the host.  I'm going to update the host to latest Xen 
>>4.4 now
>>     hoping this is a old bug.
>>     Here's from xen logs
>>     [2016-06-22 09:13:50 1958] DEBUG (XendDomainInfo:105)
>>     XendDomainInfo.create(['vm', ['name', 'xxx'], ['memory', 2048],
>>     ['on_xend_start', 'ignore'], ['on_xend_stop', 'ignore'], ['vcpus', 
>>2],
>>     ['oos', 1], ['image', ['linux', ['kernel', 
>>'/kernels/vmlinux-2.6.18.8-4'],
>>     ['videoram', 4], ['args', 'root=/dev/xvda ro xencons=tty 
>>console=tty1 '],
>>     ['tsc_mode', 0], ['nomigrate', 0]]], ['s3_integrity', 1], 
>>['device',
>>     ['vbd', ['uname', 'phy:vg/fs_6818'], ['dev', 'xvda'], ['mode', 
>>'w']]],
>>     ['device', ['vbd', ['uname', 'phy:vg/fs_6819'], ['dev', 'xvdb'], 
>>['mode',
>>     'w']]], ['device', ['vif', ['rate', '40mb/s'], ['mac',
>>     'FE:FD:48:01:F1:E7']]]])
>>     [2016-06-22 09:13:50 1958] DEBUG (XendDomainInfo:2504)
>>     XendDomainInfo.constructDomain
>>     [2016-06-22 09:13:50 1958] DEBUG (balloon:187) Balloon: 7602632 
>>KiB free;
>>     need 16384; done.
>>
>
>Hmm.. so you're using (dom0) memory ballooning? You might want to 
>disable it.
>Things worked better without ballooning (at least with xend).
>
>
>-- Pasi
>
>>     [2016-06-22 09:13:50 1958] ERROR (XendDomainInfo:2566) (12, 
>>'Cannot
>>     allocate memory')
>>     Traceback (most recent call last):
>>       File 
>>"/usr/lib64/python2.6/site-packages/xen/xend/XendDomainInfo.py",
>>     line 2561, in _constructDomain
>>         target = self.info.target())
>>     Error: (12, 'Cannot allocate memory')
>>     [2016-06-22 09:13:50 1958] ERROR (XendDomainInfo:490) VM start 
>>failed
>>     Traceback (most recent call last):
>>       File 
>>"/usr/lib64/python2.6/site-packages/xen/xend/XendDomainInfo.py",
>>     line 475, in start
>>         XendTask.log_progress(0, 30, self._constructDomain)
>>       File "/usr/lib64/python2.6/site-packages/xen/xend/XendTask.py", 
>>line
>>     209, in log_progress
>>         retval = func(*args, **kwds)
>>       File 
>>"/usr/lib64/python2.6/site-packages/xen/xend/XendDomainInfo.py",
>>     line 2572, in _constructDomain
>>         raise VmError(failmsg)
>>     VmError: Creating domain failed: name=xxx
>>     [2016-06-22 09:13:50 1958] ERROR (XendDomainInfo:110) Domain 
>>construction
>>     failed
>>     Traceback (most recent call last):
>>       File 
>>"/usr/lib64/python2.6/site-packages/xen/xend/XendDomainInfo.py",
>>     line 108, in create
>>         vm.start()
>>       File 
>>"/usr/lib64/python2.6/site-packages/xen/xend/XendDomainInfo.py",
>>     line 475, in start
>>         XendTask.log_progress(0, 30, self._constructDomain)
>>       File "/usr/lib64/python2.6/site-packages/xen/xend/XendTask.py", 
>>line
>>     209, in log_progress
>>         retval = func(*args, **kwds)
>>       File 
>>"/usr/lib64/python2.6/site-packages/xen/xend/XendDomainInfo.py",
>>     line 2572, in _constructDomain
>>         raise VmError(failmsg)
>>     VmError: Creating domain failed: name=xxx
>>     --
>>     Shaun
>