Hi Ananthan,
Thank you very much for replying,
some details:
System with 4GB ram is our test environment,our server is 48 GB but
ok, that sounds more appropriate :-)
comes with a single hdd,but need to run 7 vms on it.So i believe sharing
a single hdd among 7 vms and host machine simply adds disk i/o and can
cause serious bottlenecks
io is definitly the main bottleneck for common workload in virtualisation.
,to avoid that i thought of running vm on
/dev/shm and take regular backups.i dont know whether i can do this with
XCP,but i have done it with XEN by moving *.img* file to /dev/shm and
starting vm from there. Once again thanks alot.
if you don't want to invest in a good raid card with bbu (Areca rocks),
you can still create a software raid with linux md and have decent
performace.
Software Raid cannot be setup at install time, but if you can add after
first install (you first create the /dev/md0 with a few disks, and then
define a storage repository on top). It not fully safe since there is no
bbu and it does not deactivate hdd cache, but it should fine if you have
manageable ups.
one more thing:
I believe your suggestion for memory is also applicable to hardisk
also.since df -h is showing around 4 Gb.
XCP creates a 4GiB partition for dom0 system, then an empty 4GiB
partition (remnant of xenserver), and then create a big LVM partition
(standard install), or a ext3 partition (if you chose thin provisioning
during install), so extra disk space is just around the corner.
Cheers,
Denis
PS : don't forget to respond to the mailing list
Thanking You,
Ananthan
On Mon, Aug 13, 2012 at 5:43 PM, Denis Cardon
<[email protected]
<mailto:[email protected]>> wrote:
Hi Ananthan,
Thank you very much for clarifying my
concern.But what i really want was to run all the Virtual Machine on
shared memory /dev/shm (tmpfs).i have done it using xen by copying
virtual image .img files to /dev/shm and started from there.But for
doing that when i checked memory status i found this thing.is
<http://thing.is>
<http://thing.is> there a way to make the VM run on /dev/shm
rather on
HDD,to avoid i/o wait.
you can increase the RAM of dom0 by changing the dom0_mem value in
extlinux.conf and restarting your XCP server. However 4GiB is not a
lot of ram and you won't have much room for putting both vm content
and ram...
Afterward, you will have to create a storage repository (xe
sr-create) on /dev/shm to store your vdi there. I don't know if it
works out of the box on ramdisk.
Cheers,
Denis
PS : please, try to answer on the mailing list.
On Mon, Aug 13, 2012 at 2:02 PM, Denis Cardon
<denis.cardon@tranquil-it-__systems.fr
<mailto:[email protected]>
<mailto:denis.cardon@tranquil-__it-systems.fr
<mailto:[email protected]>>> wrote:
Hi Ananthan,
installed XCP 1.1 on intel i5 second gen
processor with 4
GB RAM
but *top,free -m,cat /proc/meminfo* is showing only 309
mb of
RAM space....
How can it be fixed..
dom0 memory is constrained by parameters in the extlinux
boot param
in/boot/extlinux.conf (look for the dom0_mem). Here in my
conf below
it is set to 752Mo, and it may vary after installation
depending on
the whole RAM of the server.
cat /boot/extlinux.conf
...
label xe
# XCP
kernel mboot.c32
append /boot/xen.gz dom0_mem=752M lowmem_emergency_pool=1M
crashkernel=64M@32M console= vga=mode-0x0311 ---
/boot/vmlinuz-2.6-xen root=LABEL=root-nddcwqei ro xencons=hvc
console=hvc0 console=tty0 quiet vga=785 splash ---
/boot/initrd-2.6-xen.img
...
RAM used by dom0 is not available for virtual machines, it
is used
for network bridging and physical block device handling, etc.
So it means that you have 4GiB - 300MiB of RAM available
for your
virtual machines.
Cheers,
Denis
*ouput from xsconsole *
*System Memory*
Total memory 4096 MB
Populated memory sockets 2
Total memory sockets 4
BIOS Information
Version BLH6710H.86A.0119.2011.0523.____1030
Vendor Intel Corp
*Processor Details*
Logical CPUs 4
Populated CPU Sockets 1
Total CPU Sockets 1
*Description*
x Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz
*free -m*
total used free shared buffers
cached
Mem: 309 284 24 0
6
116
-/+ buffers/cache: 161 147
Swap: 511 0 511
*top*
Mem: 316416k total, 291956k used, 24460k free,
6644k
buffers
Swap: 524280k total, 0k used, 524280k free,
119156k
cached
*cat /proc/meminfo*
MemTotal: 316416 kB
MemFree: 24616 kB
Buffers: 6584 kB
Cached: 119072 kB
SwapCached: 0 kB
Active: 64236 kB
Inactive: 100496 kB
Active(anon): 38888 kB
Inactive(anon): 5024 kB
Active(file): 25348 kB
Inactive(file): 95472 kB
Unevictable: 6436 kB
Mlocked: 6436 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 316416 kB
LowFree: 24616 kB
SwapTotal: 524280 kB
SwapFree: 524280 kB
Dirty: 532 kB
Writeback: 0 kB
AnonPages: 45544 kB
Mapped: 18040 kB
Shmem: 132 kB
Slab: 18636 kB
SReclaimable: 9612 kB
SUnreclaim: 9024 kB
KernelStack: 1520 kB
PageTables: 0 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 682488 kB
Committed_AS: 660896 kB
VmallocTotal: 245752 kB
VmallocUsed: 4576 kB
VmallocChunk: 237148 kB
DirectMap4k: 754492 kB
DirectMap2M: 0 kB
Regards,
Ananthan,
India
This body part will be downloaded on demand.
--
Denis Cardon
Tranquil IT Systems
44 bvd des pas enchantés
44230 Saint Sébastien sur Loire
tel : +33 (0) 2.40.97.57.57
<tel:%2B33%20%280%29%202.40.97.57.57>
<tel:%2B33%20%280%29%202.40.__97.57.57>
http://www.tranquil-it-____systems.fr
<http://www.tranquil-it-__systems.fr>
<http://www.tranquil-it-__systems.fr
<http://www.tranquil-it-systems.fr>>
--
Denis Cardon
Tranquil IT Systems
44 bvd des pas enchantés
44230 Saint Sébastien sur Loire
tel : +33 (0) 2.40.97.57.57 <tel:%2B33%20%280%29%202.40.97.57.57>
http://www.tranquil-it-__systems.fr <http://www.tranquil-it-systems.fr>
--
Denis Cardon
Tranquil IT Systems
44 bvd des pas enchantés
44230 Saint Sébastien sur Loire
tel : +33 (0) 2.40.97.57.57
http://www.tranquil-it-systems.fr
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