[CentOS] error creating Centos 5.1 x32 dum_U instance on CentOS5.1x64

Sat Mar 1 04:35:06 UTC 2008
Rudi Ahlers <Rudi at SoftDux.com>

Ross S. W. Walker wrote:
> Rudi Ahlers wrote:
>   
>> Rudi Ahlers wrote:
>>     
>>> Ross S. W. Walker wrote:
>>>       
>>>> Nah, RHEL 5.1+ supports 32-bit domU (PAE and non PAE) on 
>>>>         
>> 64-bit dom0.
>>     
>>>> Actually RHEL Xen is 3.1 with the brain damaged 3.0 
>>>>         
>> userland utilities.
>>     
>>>> -Ross
>>>>
>>>>
>>>> ----- Original Message -----
>>>>
>>>>         
>>> I've run into an interesting problem, which trying to 
>>>       
>> install a 64bit 
>>     
>>> guest:
>>>
>>>
>>> libvir: Xen Daemon error : POST operation failed: (xend.err 'Error 
>>> creating domain: I need 524288 KiB, but dom0_min_mem is 262144 and 
>>> shrinking to 262144 KiB would leave only 461040 KiB free.')
>>> Traceback (most recent call last):
>>>  File "/usr/sbin/virt-install", line 633, in ?
>>>    main()
>>>  File "/usr/sbin/virt-install", line 578, in main
>>>    dom = guest.start_install(conscb,progresscb)
>>>  File "/usr/lib/python2.4/site-packages/virtinst/Guest.py", 
>>>       
>> line 649, 
>>     
>>> in start_install
>>>    return self._do_install(consolecb, meter)
>>>  File "/usr/lib/python2.4/site-packages/virtinst/Guest.py", 
>>>       
>> line 666, 
>>     
>>> in _do_install
>>>    self.domain = self.conn.createLinux(install_xml, 0)
>>>  File "/usr/lib64/python2.4/site-packages/libvirt.py", line 503, in 
>>> createLinux
>>>    if ret is None:raise 
>>>       
>> libvirtError('virDomainCreateLinux() failed', 
>>     
>>> conn=self)
>>> libvirt.libvirtError: virDomainCreateLinux() failed POST operation 
>>> failed: (xend.err 'Error creating domain: I need 524288 KiB, but 
>>> dom0_min_mem is 262144 and shrinking to 262144 KiB would leave only 
>>> 461040 KiB free.')
>>>
>>>
>>> [root at gimbli ~]# uname -a
>>> Linux gimbli 2.6.18-53.1.13.el5xen #1 SMP Tue Feb 12 
>>>       
>> 13:33:07 EST 2008 
>>     
>>> x86_64 x86_64 x86_64 GNU/Linux
>>> [root at gimbli ~]# cat /proc/meminfo
>>> MemTotal:       713728 kB
>>> MemFree:        503028 kB
>>> Buffers:         25284 kB
>>> Cached:          69356 kB
>>> SwapCached:          0 kB
>>> Active:          67144 kB
>>> Inactive:        55820 kB
>>> HighTotal:           0 kB
>>> HighFree:            0 kB
>>> LowTotal:       713728 kB
>>> LowFree:        503028 kB
>>> SwapTotal:     2096472 kB
>>> SwapFree:      2096472 kB
>>> Dirty:              40 kB
>>> Writeback:           0 kB
>>> AnonPages:       28280 kB
>>> Mapped:           7584 kB
>>> Slab:            17004 kB
>>> PageTables:       2316 kB
>>> NFS_Unstable:        0 kB
>>> Bounce:              0 kB
>>> CommitLimit:   2453336 kB
>>> Committed_AS:   145988 kB
>>> VmallocTotal: 34359738367 kB
>>> VmallocUsed:      2204 kB
>>> VmallocChunk: 34359735799 kB
>>>
>>>
>>> Even though Linux reports only 713MB RAM, the machine has 
>>>       
>> 2GB RAM. How 
>>     
>>> / where do I fix this?
>>>
>>>       
>> I also saw this:
>>
>> xentop - 18:04:44   Xen 3.1.0-53.1.13.el5
>> 4 domains: 1 running, 1 blocked, 0 paused, 0 crashed, 0 
>> dying, 0 shutdown
>> Mem: 2086396k total, 2076932k used, 9464k free    CPUs: 2 @ 2666MHz
>>       NAME  STATE   CPU(sec) CPU(%)     MEM(k) MEM(%)  MAXMEM(k) 
>> MAXMEM(%) VCPUS NETS NETTX(k) NETRX(k) VBDS   VBD_OO   VBD_RD 
>>   VBD_WR SSID
>>   Domain-0 -----r        122    1.6     713728   34.2   no 
>> limit       
>> n/a     2    4     4091   121100    0        0        0        0    0
>>       vm01 --b---         42    0.2     262000   12.6     262144      
>> 12.6     1    1     1680    98659    0        0        0        0    0
>>
>>
>>
>> xen top shows the full RAM, but the system itself doesn't?
>>     
>
> That's because 'free' or 'top' in dom0 is only going to show the
> memory allocated to dom0.
>
> Don't forget dom0 is a virtual machine too!
>
> 'xm' top will show the total memory for the system.
>
> I suggest removing the dom0_mem restriction in /boot/grub/menu.lst
> if you have it, and making sure (dom0-min-mem 512) is set in
> /etc/xen/xend-config.sxp, especially if you are using X on the
> system. This will make sure that dom0 will always have at least
> 512MB of mem available to it and if necessary can balloon out and
> shrink back.
>
>
>
> ______________________________________________________________________
>   

Thanx.

There was no dom0_mem restriction in /boot/grub/menu.list, but the

(dom0-min-mem 256) in /etc/xen/xend-config.sxp was a bit low, so I adjusted it to 512, so now free -m shows quite a bit more RAM on the system. 

I have send in a request to join centos-virt at centos.org - but apparently someone needs to approve me as a list user.... I'd really like to get this think cracking :(






-- 

Kind Regards
Rudi Ahlers
CEO, SoftDux

Web:   http://www.SoftDux.com
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