[Xen-users] Is LVM really that much slower than Container?

[Tim Kaufmann <tim@xxxxxxxxxxxxxx>]

Hi,

I installed Windows XP SP3 to two domU. Only difference between them:  
one is stored in a container (let's call it domU1), while the other  
one (domU2) is stored on a logical volume made available by the dom0.
I have a tar.gz-file which is 400 MB in size. Copying this file from a  
samba server on the network via LAN to domU1 takes 11 seconds on domU1  
and a little more than 2 minutes on domU2.
Creating a local copy of the file takes 3 seconds on domU1 and 80  
seconds on domU2. Is that a penalty LVM-users have to live with or is  
something wrong with my system?
Tim


Hardware
========
Asus P5Q-EM DO (Intel Q45 Chipset with VT-d)
Intel Core 2 Quad Q9550 (E0), 4x 2.83GHz
8 GB RAM
latest Bios, not overclocked
5 x Western Digital RE3 1000GB, SATA II (WD1002FBYS) connected to  
onbord SATA
domO
=====
Ubuntu 8.10 with linux-xen0-2.6.27.5 (hg checkout), xfce, convirt
/boot with 500 MB on RAID 1 over all 5 drives
swap with 2 GB on each of the 5 drives
LVM over RAID 5 over the remaining space of the 5 drives, / on logical  
volume
domU1
=====
import os, re
arch=os.uname()[4]
if re.search('64', arch):
    arch_libdir = 'lib64'
else:
    arch_libdir = 'lib'
name='XP-Test-Container'
kernel='/usr/lib/xen/boot/hvmloader'
builder='hvm'
memory=512
shadow_memory=10
#vcpus=1
#cpus = "0"        # all vcpus run on CPU0
pae=1
acpi=0
apic=0
#vif=['mac=00:16:3e:4d:f5:bc, bridge=xenbr0']
vif=['']
disk=['file:/var/cache/convirt/vm_disks/XP-Test- 
Container.disk.xm,hda,w', 'file:/var/cache/convirt/vm_disks/ 
winxpprof.iso,hdc:cdrom,r']
device_model='/usr/' + arch_libdir + '/xen/bin/qemu-dm'

# Boots from CDROM.
# Change to 'c' after windows installation in order to boot from disk.
boot='d'
#boot='c'

sdl=0
vnc=1
vncunused=1
stdvga=0
extra=''
on_reboot='restart'
on_shutdown='destroy'
ramdisk=''
image_name='Windows_CD_Install'
on_crash='restart'
bootloader=''
vcpus=1
root=''
platform='xen'
network_mode='user'
usb=1
usbdevice='tablet'

STORAGE_STATS={'DISK_STATS': {'/var/cache/convirt/vm_disks/ 
winxpprof.iso': {'DEV_TYPE': 'FILE', 'IS_LOCAL': True, 'DISK_SIZE':  
638042112, 'DISK_NAME': '/var/cache/convirt/vm_disks/winxpprof.iso'},  
'/var/cache/convirt/vm_disks/XP-Test-Container.disk.xm': {'DEV_TYPE':  
'FILE', 'IS_LOCAL': True, 'DISK_SIZE': 20971520001, 'DISK_NAME': '/var/ 
cache/convirt/vm_disks/XP-Test-Container.disk.xm'}},  
'LOCAL_ALLOCATION': 21609562113, 'SHARED_ALLOCATION': 0}
image_id='b7279a971653b0c7d7c5c7cfa6d783d9'
image_conf='/var/log/convirt/image_store/Windows_CD_Install/ 
Windows_CD_Install_XP-Test-Container_image.conf'
uuid='80dfff4c-227a-e8bc-432d-2dcf15436304'


domU2
======
# Automtically generated by ConVirt
import os, re
arch=os.uname()[4]
if re.search('64', arch):
    arch_libdir = 'lib64'
else:
    arch_libdir = 'lib'


name='XP-Test-LVM'

kernel='/usr/lib/xen/boot/hvmloader'
builder='hvm'


memory=512
shadow_memory=10
#vcpus=1
#cpus = "0"        # all vcpus run on CPU0

pae=1
acpi=0
apic=0
#vif=['mac=00:16:3e:44:65:6f, bridge=xenbr0']
vif=['']
disk=['phy:/dev/raidvg/XP-Test-LVM.disk.xm,hda,w', 'file:/var/cache/ 
convirt/vm_disks/winxpprof.iso,hdc:cdrom,r']
device_model='/usr/' + arch_libdir + '/xen/bin/qemu-dm'

# Boots from CDROM.
# Change to 'c' after windows installation in order to boot from disk.
boot='d'
#boot='c'

sdl=0
vnc=1
vncunused=1
stdvga=0
extra=''
on_reboot='restart'
on_shutdown='destroy'
ramdisk=''
image_name='Windows_CD_Install_LVM'
on_crash='restart'
bootloader=''
vcpus=1
root=''
platform='xen'
network_mode='user'
usb=1
usbdevice='tablet'

STORAGE_STATS={'DISK_STATS': {'/var/cache/convirt/vm_disks/ 
winxpprof.iso': {'DEV_TYPE': 'FILE', 'IS_LOCAL': True, 'DISK_SIZE':  
638042112, 'DISK_NAME': '/var/cache/convirt/vm_disks/winxpprof.iso'},  
'/dev/raidvg/XP-Test-LVM.disk.xm': {'DEV_TYPE': 'BLOCK', 'IS_LOCAL':  
True, 'DISK_SIZE': 20971520000, 'DISK_NAME': '/dev/raidvg/XP-Test- 
LVM.disk.xm'}}, 'LOCAL_ALLOCATION': 21609562112, 'SHARED_ALLOCATION': 0}
image_id='d500a710e92058067521fbe7063de445'
image_conf='/var/log/convirt/image_store/Windows_CD_Install_LVM/ 
Windows_CD_Install_LVM_XP-Test-LVM_image.conf'
uuid='7f5b9160-dda6-56e5-1ba0-2071e6ceb778'





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