[CentOS] new memory not getting regonized

Sat Aug 27 12:35:30 UTC 2011
Simon Matter <simon.matter at invoca.ch>

> 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 at 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".

Regards,
Simon