[CentOS] new memory not getting regonized

Sat Aug 27 11:22:56 UTC 2011

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

apprecite once again and thnaks

regards

sylvan

On Fri, Aug 26, 2011 at 3:29 PM, Dennis Jacobfeuerborn <
dennisml at conversis.de> wrote:

> On 08/26/2011 12:51 PM, benedict dcunha wrote:
> > Thanks Leonard,
> > Thanks for the immedite reply . apprecite.
> > actually many post s say the PAE kernel required for addressing more than
> 4
> > gb ram . but since my server already detects 32 gb ram , detecting 64
> also
> > should not be an issue..
>
> "many posts say" a lot of things. Either these posts are specifically
> talking about 32bit systems or they are wrong.
> With a 32bit integer you can only address 4gb of ram so a hack was devised
> to make it possible go beyond that limit called PAE.
> Since with 64bit you no longer have that problem PAE doesn't exist on a
> 64bit system.
>
> http://en.wikipedia.org/wiki/Physical_Address_Extension
>
> > but just wondering why??.
>
> No idea but it has nothing to do with PAE. Can you post the output of "xm
> info"?
>
> Regards,
>   Dennis
>  _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
>
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