Has anyone seen this issue below.
Issue:
I cannot see most of my RAM from Domain-0 - even after a reboot
I have a CentOS 5.3 box with 16GB of ram and 8 CPU cores. I''ve set
Domain-0''s memory to 1GB and my two DomUs to 4 GB and 2GB respectively
(see
blelow).
#xm list
Name ID Mem(MiB) VCPUs State
Time(s)
Domain-0 0 1024 8
r------ 2023.7
guest1 1 4096 1
r------ 83.3
guest2 3 2048 1
r------ 299.5
( ID #2 is missing because I destroyed it, removed it''s config file and
it''s
disk - it''s gone for good!)
When I check my system memory from Domain-0 using ''free -m''
(the ''- m'' just
means show me in Megabytes), it shows that my box only has a total of 1 GB!
What the heck. /proc/meminfo shows the same thing! Where did my ram go?
Any thoughts guys?
# free -m
* total * used free shared buffers cached
Mem: *1024 * 783 240 0 57 101
-/+ buffers/cache: 625 398
Swap: 3967 0 3967
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Have you ever been able to? Dom0 is a virtual machine that only has 1 GiB. Try xm info. From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Kevin McKeon Sent: Friday, April 24, 2009 11:05 To: Xen-users@lists.xensource.com Subject: [Xen-users] Cannot see my memory - why? Has anyone seen this issue below. Issue: I cannot see most of my RAM from Domain-0 - even after a reboot I have a CentOS 5.3 box with 16GB of ram and 8 CPU cores. I've set Domain-0's memory to 1GB and my two DomUs to 4 GB and 2GB respectively (see blelow). #xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 1024 8 r------ 2023.7 guest1 1 4096 1 r------ 83.3 guest2 3 2048 1 r------ 299.5 ( ID #2 is missing because I destroyed it, removed it's config file and it's disk - it's gone for good!) When I check my system memory from Domain-0 using 'free -m' (the '- m' just means show me in Megabytes), it shows that my box only has a total of 1 GB! What the heck. /proc/meminfo shows the same thing! Where did my ram go? Any thoughts guys? # free -m total used free shared buffers cached Mem: 1024 783 240 0 57 101 -/+ buffers/cache: 625 398 Swap: 3967 0 3967 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
That''s just how Xen works. Dom-0 is really a virtual machine also. If you want it to have more RAM, allocate more to it, just like the others. On Fri, Apr 24, 2009 at 08:10, Dustin Henning <Dustin.Henning@prd-inc.com>wrote:> Have you ever been able to? Dom0 is a virtual machine that only has 1 GiB. > Try xm info. > > From: xen-users-bounces@lists.xensource.com > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Kevin McKeon > Sent: Friday, April 24, 2009 11:05 > To: Xen-users@lists.xensource.com > Subject: [Xen-users] Cannot see my memory - why? > > Has anyone seen this issue below. > Issue: > I cannot see most of my RAM from Domain-0 - even after a reboot > > I have a CentOS 5.3 box with 16GB of ram and 8 CPU cores. I''ve set > Domain-0''s memory to 1GB and my two DomUs to 4 GB and 2GB respectively (see > blelow). > > #xm list > Name ID Mem(MiB) VCPUs State > Time(s) > Domain-0 0 1024 8 > r------ 2023.7 > guest1 1 4096 1 > r------ 83.3 > guest2 3 2048 1 > r------ 299.5 > > ( ID #2 is missing because I destroyed it, removed it''s config file and > it''s > disk - it''s gone for good!) > > When I check my system memory from Domain-0 using ''free -m'' (the ''- m'' just > means show me in Megabytes), it shows that my box only has a total of 1 GB! > What the heck. /proc/meminfo shows the same thing! Where did my ram go? > > Any thoughts guys? > > > # free -m > total used free shared buffers cached > Mem: 1024 783 240 0 57 101 > -/+ buffers/cache: 625 398 > Swap: 3967 0 3967 > > > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- [EOM] _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Just to rehash what''s already been said, Domain 0 is a paravirt VM in reality, so the amount of ram you allocate to it is what you will see when using local tools like free, /proc/meminfo, top, etc. To see the full system ram, yoyu need to use the xm tools... and in this case, ''xm info'' which will show you all the system resources, as opposed to the resources available to dom0. Also, you have 16GB ram on the system... you probably already know this, but be aware that without a PAE enabled kernel (if you''re using 32bit Xen) you''ll only see 4GB of this. PAE will allow you to use up to 16, or maybe 32 (I don''t remember what the upper limit for PAE enabled Xen is off the top of my head). I always ran 64bit so that limit was never an issue... Cheers Jeff _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Just run the dmidecode on the Dom0 and you will see the exact memory on the server. and if you increased the memory of the DomU then you will get it in free -m. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks for the details Jeff, that really clears things up a lot. I''ve only allocated 1GB of RAM to my 64bit Domain-0s and that''s all that shows up with free, /etc/meminfo and top, but I can see all of my RAM using ''xm list''. Thanks again On Fri, Apr 24, 2009 at 2:25 PM, Jeff Lane <dreadpiratejeff@gmail.com>wrote:> Just to rehash what''s already been said, Domain 0 is a paravirt VM in > reality, so the amount of ram you allocate to it is what you will see > when using local tools like free, /proc/meminfo, top, etc. > > To see the full system ram, yoyu need to use the xm tools... and in > this case, ''xm info'' which will show you all the system resources, as > opposed to the resources available to dom0. > > Also, you have 16GB ram on the system... you probably already know > this, but be aware that without a PAE enabled kernel (if you''re using > 32bit Xen) you''ll only see 4GB of this. PAE will allow you to use up > to 16, or maybe 32 (I don''t remember what the upper limit for PAE > enabled Xen is off the top of my head). > > I always ran 64bit so that limit was never an issue... > > Cheers > Jeff >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users