On 08/27/2011 02:35 PM, Simon Matter wrote:
Thanks Guys
really apprecite your quick responses. ( Dennis was right in tellin me about PAE since my system is 64 bit and if I do run yum install kernel-PAE there is nothing found.)
actually i found something more as i was figuring my issue out.
when I do a top i see the following
Tasks: 285 total, 1 running, 284 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.0%sy, 0.0%ni, 99.8%id, 0.2%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 33554432k total, 15430836k used, 18123596k free, 323176k buffers Swap: 2819396k total, 0k used, 2819396k free, 13860960k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
when I run cat /proc/meminfo i see
----MemTotal: 33554432 kB MemFree: 18123588 kB Buffers: 323192 kB Cached: 13860992 kB SwapCached: 0 kB Active: 9601264 kB Inactive: 4643904 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 33554432 kB LowFree: 18123588 kB SwapTotal: 2819396 kB SwapFree: 2819396 kB Dirty: 8 kB Writeback: 0 kB AnonPages: 60972 kB Mapped: 12528 kB Slab: 360860 kB PageTables: 18444 kB NFS_Unstable: 0 kB Bounce: 0 kB CommitLimit: 19596612 kB Committed_AS: 394740 kB VmallocTotal: 34359738367 kB VmallocUsed: 3304 kB VmallocChunk: 34359733919 kB
actually I had run the above 2 command and found the memory was 32gb but as dennis said when I run the command xm info
[root@hypervisor2 ~]# xm info host : hypervisor2 release : 2.6.18-194.32.1.el5xen version : #1 SMP Wed Jan 5 18:44:24 EST 2011 machine : x86_64 nr_cpus : 16 nr_nodes : 1 sockets_per_node : 2 cores_per_socket : 4 threads_per_core : 2 cpu_mhz : 2527 hw_caps : bfebfbff:28100800:00000000:00000140:009ce3bd:00000000:00000001 total_memory : 65527 free_memory : 22989 node_to_cpu : node0:0-15 xen_major : 3 xen_minor : 1 xen_extra : .2-194.32.1.el5 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64 xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : unavailable cc_compiler : gcc version 4.1.2 20080704 (Red Hat 4.1.2-48) cc_compile_by : mockbuild cc_compile_domain : centos.org cc_compile_date : Wed Jan 5 17:43:03 EST 2011 xend_config_format : 2
and then I ran xm top i see
5 domains: 1 running, 4 blocked, 0 paused, 0 crashed, 0 dying, 0 shutdown Mem: 67099744k total, 43558844k used, 23540900k free CPUs: 16 @ 2527MHz 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 8401 2.4 33554688 50.0 no limit n/a 16 4 1892 16848120 0 0 0 0 0 sepmback --b--- 9758 2.6 2105220 3.1 4210688 6.3 4 1 0 0 1 0 0 0 0 winserver2 --b--- 5758 0.9 1056644 1.6 4210688 6.3 1 1 0 0 1 0 0 0 0 wsusserver --b--- 25812 11.4 3256196 4.9 8404992 12.5 4 1 0 0 1 0 0 0 0 zimbra --b--- 26183 7.8 2105220 3.1 4210688 6.3 4 1 0 16 1 0 0 0 0
so the above 2 command show me 64gb
Now I m confused ..
Is my Centos XEN server actually using the 64 bit ... and which command actually show me the right memory status
I'm not sure but I think everything is okay with your box. "xm top" shows that your box run with 64Gb memory, and what "top" shows is that your Dom0 OS runs with 32Gb memory, which means your DomU's take the other 32Gb. Did you up the memory settings in your virtual hosts configuration? After doing so you should see the Dom0 memory to go down when looking at it with "top".
Benedict is right. Remember that under Xen Dom0 is really just another VM with special privileges. In fact on all my host systems I restrict Dom0 to 1G of ram by adding a "dom0_mem=1024M" argument to the grub configuration. In practice Xen should reduce the amount of ram used by Dom0 dynamically as needed for VMs i.e. if your virtual machines use 48G of ram then dom0 should only show 16G left. A while ago this mechanism lead to instability though so a general recommendation was to set dom0 memory to a fixed 1G or 512M to not rely on this dynamic memory handling.
Check this out for example: http://lists.xensource.com/archives/html/xen-users/2008-06/msg00729.html
Regards, Dennis