Xen users - Jan 2009 - DomU in it''s own LVM partition fails to boot CentOS 5.2 Dom0/U

I''m trying to do what I think would be relatively simple but
can''t seem to
make it work. Essentially I want to create several domU''s running
CentOS
each with it''s own LVM partition for increased performance over image
files.

Initially I did a test with image files and everything went fine, I booted
the supplied initrd and vmlinuz images installed CentOS from http, etc...
However, the performance of image files is pretty slow for what I intend to
use this for (Web/DB servers). So I wanted to do the same thing but in a
dedicated partition. Problem is, when I do this and try to install via http,
the disk doesn''t show up in the installer, it just shows a
"#". This appears
to be expected when using a dedicated partition and the solution seems to be
to copy an image to my partition and go that route. I tried this 2 different
ways: 1: jailtime image 2: copy of my dom0 OS. For the jailtime image using
the supplied config file with my disk substituted:

kernel = "/var/lib/xen/boot/CentOS/CentOS_5_x64_vmlinuz"
name = "guest01"
memory = "1024"
disk = [ ''phy:/dev/VolGroup00/guest01,xvda1,w'', ]
vif = [ ''bridge=xenbr0'', ]
vcpus=1
root="/dev/xvda1"
extra = "fastboot"
on_reboot = ''restart''
on_crash = ''restart''

I get the following error:

VFS: Cannot open root device "xvda1" or unknown-block(0,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block(0,0)

When I try to copy my own OS the file copy takes forever (only 20G) and my
load average starts creeping up to 3+, which I assume may have to do with
the fact that I''m running cp -ax / /mnt/guest01 which may loop copying
/mnt/guest01 to itself or something similar? Or maybe this is expected and
I''m just impatient :)

Anyways, long story short, is there a way to install to a partition via HTTP
like with disk images? If not, what am I doing wrong using the prebuilt
images?


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You need a ramdisk configured.

For instance to kickstart a Centos DomU I have:
kernel = "/etc/xen/centos52_x86_install.vmlinuz"
ramdisk = "/etc/xen/centos52_x86_install.initrd.img"
extra = "ks=http://192.168.42.60/ks-xen-hit42.cfg"

Where the vmlinuz and initrd files are from the images/xen directory
from the Centos install media.

After the installation is complete comment out the kernel, ramdisk and
extra entries and add
bootloader="/usr/bin/pygrub"

to the config file.

On Sat, 2009-01-24 at 13:19 -0500, Peter Hoose wrote:
> I''m trying to do what I think would be relatively simple but
can''t
> seem to make it work. Essentially I want to create several domU''s
> running CentOS each with it''s own LVM partition for increased
> performance over image files.
> 
> Initially I did a test with image files and everything went fine, I
> booted the supplied initrd and vmlinuz images installed CentOS from
> http, etc... However, the performance of image files is pretty slow
> for what I intend to use this for (Web/DB servers). So I wanted to do
> the same thing but in a dedicated partition. Problem is, when I do
> this and try to install via http, the disk doesn''t show up in the
> installer, it just shows a "#". This appears to be expected when
using
> a dedicated partition and the solution seems to be to copy an image to
> my partition and go that route. I tried this 2 different ways: 1:
> jailtime image 2: copy of my dom0 OS. For the jailtime image using the
> supplied config file with my disk substituted:
> 
> kernel = "/var/lib/xen/boot/CentOS/CentOS_5_x64_vmlinuz"
> name = "guest01"
> memory = "1024"
> disk = [ ''phy:/dev/VolGroup00/guest01,xvda1,w'', ]
> vif = [ ''bridge=xenbr0'', ]
> vcpus=1
> root="/dev/xvda1"
> extra = "fastboot"
> on_reboot = ''restart''
> on_crash = ''restart''
> 
> I get the following error:
> 
> VFS: Cannot open root device "xvda1" or unknown-block(0,0)
> Please append a correct "root=" boot option
> Kernel panic - not syncing: VFS: Unable to mount root fs on
> unknown-block(0,0)
> 
> When I try to copy my own OS the file copy takes forever (only 20G)
> and my load average starts creeping up to 3+, which I assume may have
> to do with the fact that I''m running cp -ax / /mnt/guest01 which
may
> loop copying /mnt/guest01 to itself or something similar? Or maybe
> this is expected and I''m just impatient :)
> 
> Anyways, long story short, is there a way to install to a partition
> via HTTP like with disk images? If not, what am I doing wrong using
> the prebuilt images? 
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users

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On Sun, Jan 25, 2009 at 1:19 AM, Peter Hoose <phoose@gmail.com>
wrote:
> I''m trying to do what I think would be relatively simple but
can''t seem to
> make it work. Essentially I want to create several domU''s running
CentOS
> each with it''s own LVM partition for increased performance over
image files.
>
Some would argue that with current implementation (i.e. with tap:aio
instead of files) and by using full (i.e. not sparse) image files you
can get a similar performance from file-based vbd compared to
LVM-based.
>From your post, I''d say you''re trying to do two things at
once :
- move from file-based to LVM-based vbd
- using whole domU disk directly as filesystem, without additional
partition/LVM on domU side.

When trying new things sometimes it''s better to do it one at a time.
> Initially I did a test with image files and everything went fine, I booted
> the supplied initrd and vmlinuz images installed CentOS from http, etc...
That''s good.
> However, the performance of image files is pretty slow for what I intend to
> use this for (Web/DB servers).
I''d recommend you try that one more time, but by making sure that :
- the generated domU config file uses tap:aio: instead of file: (I
haven''t tested virt-install in a long time, so I''m not sure
which one
it uses by default)
- use non-sparse image file
> So I wanted to do the same thing but in a
> dedicated partition. Problem is, when I do this and try to install via
http,
> the disk doesn''t show up in the installer, it just shows a
"#". This appears
> to be expected when using a dedicated partition
No it''s not. Any backend vbd on dom0 side should look the same to domU
when it''s presented as the same device (i.e. xvda). However, changing
xvda to xvda1 has the effect that you mentioned.
> and the solution seems to be
> to copy an image to my partition and go that route. I tried this 2
different
> ways: 1: jailtime image 2: copy of my dom0 OS.
Actually there''s door #3 :
- install to a file-based vbd (you got this already)
- copy files (or copy the whole domU disk with dd) to the new LVM partition
> When I try to copy my own OS the file copy takes forever (only 20G) and my
> load average starts creeping up to 3+, which I assume may have to do with
> the fact that I''m running cp -ax / /mnt/guest01 which may loop
copying
> /mnt/guest01 to itself or something similar?
"-x" should prevent that, but I don''t think you need 20G for
domU
anyway, so stay away from using bloated "template" (like your dom0).
> Anyways, long story short, is there a way to install to a partition via
HTTP
> like with disk images?
In your case I''d actually recommend you try two things :
- try non-sparse file-based (or disk images, if you prefer that term)
vbd making sure that it uses tap:aio: instead of file:
- change your domU config file to say

disk = [ ''phy:/dev/VolGroup00/guest01,xvda,w'', ]

You need this if you still want to use HTTP-install (e..g. using
virt-install or something similar). And drop the

root="/dev/xvda1"

line. You don''t need it anyway.
> If not, what am I doing wrong using the prebuilt
> images?
>From your config file, I''d say Mike made a good point: you
don''t have an initrd.
I''d rather not go into this yet though, because I''m not
familiar with
jailtime.org images, and how you create them can make "best way to
create initrd" differ.

Regards,

Fajar

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Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

> Some would argue that with current implementation (i.e. with tap:aio
> instead of files) and by using full (i.e. not sparse) image files you
> can get a similar performance from file-based vbd compared to
> LVM-based.
Sorry, I should have been more specific. I was using tap:aio with a
non-sparse file. Testing with bonnie++ showed about 10MB/s vs. my local disk
which is closer to 100MB/s+ , So I''m trying a partition as the XEN
documnetation says this has better performance (maybe this was based on
legacy ''file:'' instead of tap?)
> From your post, I''d say you''re trying to do two things at
once :
> - move from file-based to LVM-based vbd
> - using whole domU disk directly as filesystem, without additional
> partition/LVM on domU side.
> When trying new things sometimes it''s better to do it one at a
time.
Not necessarily, I just created a LVM based vbd in my dom0, I want to use
this as my ''disk'' for my domU, which I would create my
partitions on. Is
this possible, or do I need to create a /boot, / and /swap on my domU and
share those with dom0 for it to access natively? IE: Does the dom0 see this
partition as a disk that it can create partitions on, or does it see it just
like a normal partition? I''m not moving from one thing to another, this
is
my first VM on XEN and I''m just trying to find the optimal
configuration for
performance.
> No it''s not. Any backend vbd on dom0 side should look the same to
domU
> when it''s presented as the same device (i.e. xvda). However,
changing
> xvda to xvda1 has the effect that you mentioned.
Good to know, I got the impression that I could only do a NFS, or image
based (copy all files/folders over) when using a partition of a file image.
Not exactly, all the examples I found either did HTTP based with file/tap,
or image copies with disk/parition.
> Actually there''s door #3 :
> - install to a file-based vbd (you got this already)
> - copy files (or copy the whole domU disk with dd) to the new LVM
partition

I had actually tried that copying from the jailtime image, however, I think
my problem was the xvda1 issue you listed above, re-testing now.
> "-x" should prevent that, but I don''t think you need 20G
for domU
> anyway, so stay away from using bloated "template" (like your
dom0).
Ok, again I should have been more clear :D the whole partition was only 20G
the install was much smaller, but that''s besides the point :) If I can,
with
your suggestions make this work with an HTTP install or the jailtime image
I''d be happier anyway.
> In your case I''d actually recommend you try two things :
> - try non-sparse file-based (or disk images, if you prefer that term)
> vbd making sure that it uses tap:aio: instead of file:
Tried that initially, which delivered the poor performance that I''m
trying
to avoid :(
> - change your domU config file to say
> disk = [ ''phy:/dev/VolGroup00/guest01,
> xvda,w'', ]
re-testing with this, that may have been the whole issue.
> You need this if you still want to use HTTP-install (e..g.
usingvirt-install or something similar).
> And drop the
> root="/dev/xvda1"line. You don''t need it anyway.
That came from the jailtime example, I didn''t see it anywhere else
either,
dropped now, thank you.
> From your config file, I''d say Mike made a good point: you
don''t have an
initrd.
> I''d rather not go into this yet though, because I''m not
familiar with
> jailtime.org images, and how you create them can make "best way to
> create initrd" differ.
The jailtime  example didn''t have it either, my initial test with file
based
had an initrd , I re-added it for my re-test.

Thanks for you suggestions, I''ll try this again and see what I get, I
think
xvda1 thing might have been the ''major'' issue, and possibly
trying to use my
dom0 as a ''disk'' instead of creating inidividual partitions
for my domU to
access directly.

Thank you,
Peter

On Sat, Jan 24, 2009 at 2:51 PM, Fajar A. Nugraha <fajar@fajar.net> wrote:
> On Sun, Jan 25, 2009 at 1:19 AM, Peter Hoose <phoose@gmail.com>
wrote:
> > I''m trying to do what I think would be relatively simple but
can''t seem
> to
> > make it work. Essentially I want to create several domU''s
running CentOS
> > each with it''s own LVM partition for increased performance
over image
> files.
> >
> Some would argue that with current implementation (i.e. with tap:aio
> instead of files) and by using full (i.e. not sparse) image files you
> can get a similar performance from file-based vbd compared to
> LVM-based.
>
> From your post, I''d say you''re trying to do two things at
once :
> - move from file-based to LVM-based vbd
> - using whole domU disk directly as filesystem, without additional
> partition/LVM on domU side.
>
> When trying new things sometimes it''s better to do it one at a
time.
>
> > Initially I did a test with image files and everything went fine, I
> booted
> > the supplied initrd and vmlinuz images installed CentOS from http,
etc...
>
> That''s good.
>
> > However, the performance of image files is pretty slow for what I
intend
> to
> > use this for (Web/DB servers).
>
> I''d recommend you try that one more time, but by making sure that
:
> - the generated domU config file uses tap:aio: instead of file: (I
> haven''t tested virt-install in a long time, so I''m not
sure which one
> it uses by default)
> - use non-sparse image file
>
> > So I wanted to do the same thing but in a
> > dedicated partition. Problem is, when I do this and try to install via
> http,
> > the disk doesn''t show up in the installer, it just shows a
"#". This
> appears
> > to be expected when using a dedicated partition
>
> No it''s not. Any backend vbd on dom0 side should look the same to
domU
> when it''s presented as the same device (i.e. xvda). However,
changing
> xvda to xvda1 has the effect that you mentioned.
>
> > and the solution seems to be
> > to copy an image to my partition and go that route. I tried this 2
> different
> > ways: 1: jailtime image 2: copy of my dom0 OS.
>
> Actually there''s door #3 :
> - install to a file-based vbd (you got this already)
> - copy files (or copy the whole domU disk with dd) to the new LVM partition
>
> > When I try to copy my own OS the file copy takes forever (only 20G)
and
> my
> > load average starts creeping up to 3+, which I assume may have to do
with
> > the fact that I''m running cp -ax / /mnt/guest01 which may
loop copying
> > /mnt/guest01 to itself or something similar?
>
> "-x" should prevent that, but I don''t think you need 20G
for domU
> anyway, so stay away from using bloated "template" (like your
dom0).
>
> > Anyways, long story short, is there a way to install to a partition
via
> HTTP
> > like with disk images?
>
> In your case I''d actually recommend you try two things :
> - try non-sparse file-based (or disk images, if you prefer that term)
> vbd making sure that it uses tap:aio: instead of file:
> - change your domU config file to say
>
> disk = [ ''phy:/dev/VolGroup00/guest01,xvda,w'', ]
>
> You need this if you still want to use HTTP-install (e..g. using
> virt-install or something similar). And drop the
>
> root="/dev/xvda1"
>
> line. You don''t need it anyway.
>
> > If not, what am I doing wrong using the prebuilt
> > images?
>
> From your config file, I''d say Mike made a good point: you
don''t have an
> initrd.
> I''d rather not go into this yet though, because I''m not
familiar with
> jailtime.org images, and how you create them can make "best way to
> create initrd" differ.
>
> Regards,
>
> Fajar
>

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

On Sun, Jan 25, 2009 at 3:19 AM, Peter Hoose <phoose@gmail.com>
wrote:
> I just created a LVM based vbd in my dom0, I want to use
> this as my ''disk'' for my domU, which I would create my
partitions on. Is
> this possible,
Yes. For this purpose, you create one LV on dom0, map it to domU as
xvda, and install domU like what you''d do with file-based disk image.
> or do I need to create a /boot, / and /swap on my domU and
> share those with dom0 for it to access natively? IE: Does the dom0 see this
> partition as a disk that it can create partitions on, or does it see it
just
> like a normal partition?
I''m not quite sure what you mean, but you can do this :
- create two LVs on dom0, map it to domU as xvda1 (for / ) and xvda2
(for swap). You don''t need a separate /boot.
- do mkfs.ext3 and mkswap on dom0 directly on that LV (not creating
partition on top of it)
- populate domU''s filesystem (for example, by extracting
"templates"
like the one from jailtime.org, or by copying from a working domU.)
- create a suitable initrd

Regards,

Fajar

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

> Yes. For this purpose, you create one LV on dom0, map it to domU as
> xvda, and install domU like what you''d do with file-based disk
image.
Sweet!

Got much closer this time around my new config:

kernel = "/var/lib/xen/boot/CentOS/CentOS_5_x64_vmlinuz"
ramdisk = "/var/lib/xen/boot/CentOS/CentOS_5_x64_initrd.img"
extra = "text"
name = "guest01"
memory = "1024"
disk = [ ''phy:/dev/VolGroup00/guest01,xvda,w'', ]
vif = [ ''bridge=xenbr0'', ]
vcpus=1
on_reboot = ''destroy''
on_crash = ''destroy''

The disk shows up properly now, and in theory, it lets me create partitions
on it, format them, etc... But it bombs out as soon as it starts to install
with:

Error
The file system-config-securitylevel-tui-1.6.29.1-2.1.el5.x86_64.rpm
cannot be opened.  This is due to a missing file, a corrupt package
or corrupt media.  Please verify your installation source.

If you exit, your system will be left in an inconsistent state that
will likely require reinstallation.

This happens regardless of packages selected, it seems to be the first file
each time, this is install from the same mirror that I used with no problems
with file based, so it seems to still be something wrong with my disk setup?

Anyways, it''s much closer now and past the first big question/issue I
had.

If you have any ideas what caused the above error, I''d appreciate it,
if not
I''ll just hack away at it until it works.

Thanks,
  Peter

On Sat, Jan 24, 2009 at 3:29 PM, Fajar A. Nugraha <fajar@fajar.net> wrote:
> On Sun, Jan 25, 2009 at 3:19 AM, Peter Hoose <phoose@gmail.com>
wrote:
> > I just created a LVM based vbd in my dom0, I want to use
> > this as my ''disk'' for my domU, which I would create
my partitions on. Is
> > this possible,
>
> Yes. For this purpose, you create one LV on dom0, map it to domU as
> xvda, and install domU like what you''d do with file-based disk
image.
>
> > or do I need to create a /boot, / and /swap on my domU and
> > share those with dom0 for it to access natively? IE: Does the dom0 see
> this
> > partition as a disk that it can create partitions on, or does it see
it
> just
> > like a normal partition?
>
> I''m not quite sure what you mean, but you can do this :
> - create two LVs on dom0, map it to domU as xvda1 (for / ) and xvda2
> (for swap). You don''t need a separate /boot.
> - do mkfs.ext3 and mkswap on dom0 directly on that LV (not creating
> partition on top of it)
> - populate domU''s filesystem (for example, by extracting
"templates"
> like the one from jailtime.org, or by copying from a working domU.)
> - create a suitable initrd
>
> Regards,
>
> Fajar
>

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Never mind, it may have been the mirror, just tried a different one and the
install is chugging along smoothly thus far.

Thanks for all of your help!

On Sat, Jan 24, 2009 at 3:35 PM, Peter Hoose <phoose@gmail.com> wrote:
> > Yes. For this purpose, you create one LV on dom0, map it to domU as
> > xvda, and install domU like what you''d do with file-based
disk image.
>
> Sweet!
>
> Got much closer this time around my new config:
>
> kernel = "/var/lib/xen/boot/CentOS/CentOS_5_x64_vmlinuz"
> ramdisk = "/var/lib/xen/boot/CentOS/CentOS_5_x64_initrd.img"
> extra = "text"
> name = "guest01"
> memory = "1024"
> disk = [ ''phy:/dev/VolGroup00/guest01,xvda,w'', ]
> vif = [ ''bridge=xenbr0'', ]
> vcpus=1
> on_reboot = ''destroy''
> on_crash = ''destroy''
>
> The disk shows up properly now, and in theory, it lets me create partitions
> on it, format them, etc... But it bombs out as soon as it starts to install
> with:
>
> Error
> The file system-config-securitylevel-tui-1.6.29.1-2.1.el5.x86_64.rpm
> cannot be opened.  This is due to a missing file, a corrupt package
> or corrupt media.  Please verify your installation source.
>
> If you exit, your system will be left in an inconsistent state that
> will likely require reinstallation.
>
> This happens regardless of packages selected, it seems to be the first file
> each time, this is install from the same mirror that I used with no
problems
> with file based, so it seems to still be something wrong with my disk
setup?
>
> Anyways, it''s much closer now and past the first big
question/issue I had.
>
> If you have any ideas what caused the above error, I''d appreciate
it, if
> not I''ll just hack away at it until it works.
>
> Thanks,
>   Peter
>
>
> On Sat, Jan 24, 2009 at 3:29 PM, Fajar A. Nugraha <fajar@fajar.net>
wrote:
>
>> On Sun, Jan 25, 2009 at 3:19 AM, Peter Hoose <phoose@gmail.com>
wrote:
>> > I just created a LVM based vbd in my dom0, I want to use
>> > this as my ''disk'' for my domU, which I would
create my partitions on. Is
>> > this possible,
>>
>> Yes. For this purpose, you create one LV on dom0, map it to domU as
>> xvda, and install domU like what you''d do with file-based disk
image.
>>
>> > or do I need to create a /boot, / and /swap on my domU and
>> > share those with dom0 for it to access natively? IE: Does the dom0
see
>> this
>> > partition as a disk that it can create partitions on, or does it
see it
>> just
>> > like a normal partition?
>>
>> I''m not quite sure what you mean, but you can do this :
>> - create two LVs on dom0, map it to domU as xvda1 (for / ) and xvda2
>> (for swap). You don''t need a separate /boot.
>> - do mkfs.ext3 and mkswap on dom0 directly on that LV (not creating
>> partition on top of it)
>> - populate domU''s filesystem (for example, by extracting
"templates"
>> like the one from jailtime.org, or by copying from a working domU.)
>> - create a suitable initrd
>>
>> Regards,
>>
>> Fajar
>>
>
>

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Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

All good now, and I definitely see a big performance improvement with
partitions vs. tap:

/dev/xvda:
 Timing cached reads:   7856 MB in  2.00 seconds = 3936.95 MB/sec
 Timing buffered disk reads:  306 MB in  3.00 seconds = 101.95 MB/sec


Previously I was getting ~10MB/s with tap.

On Sat, Jan 24, 2009 at 3:48 PM, Peter Hoose <phoose@gmail.com> wrote:
> Never mind, it may have been the mirror, just tried a different one and the
> install is chugging along smoothly thus far.
>
> Thanks for all of your help!
>
>
> On Sat, Jan 24, 2009 at 3:35 PM, Peter Hoose <phoose@gmail.com>
wrote:
>
>> > Yes. For this purpose, you create one LV on dom0, map it to domU
as
>> > xvda, and install domU like what you''d do with file-based
disk image.
>>
>> Sweet!
>>
>> Got much closer this time around my new config:
>>
>> kernel = "/var/lib/xen/boot/CentOS/CentOS_5_x64_vmlinuz"
>> ramdisk = "/var/lib/xen/boot/CentOS/CentOS_5_x64_initrd.img"
>> extra = "text"
>> name = "guest01"
>> memory = "1024"
>> disk = [ ''phy:/dev/VolGroup00/guest01,xvda,w'', ]
>> vif = [ ''bridge=xenbr0'', ]
>> vcpus=1
>> on_reboot = ''destroy''
>> on_crash = ''destroy''
>>
>> The disk shows up properly now, and in theory, it lets me create
>> partitions on it, format them, etc... But it bombs out as soon as it
starts
>> to install with:
>>
>> Error
>> The file system-config-securitylevel-tui-1.6.29.1-2.1.el5.x86_64.rpm
>> cannot be opened.  This is due to a missing file, a corrupt package
>> or corrupt media.  Please verify your installation source.
>>
>> If you exit, your system will be left in an inconsistent state that
>> will likely require reinstallation.
>>
>> This happens regardless of packages selected, it seems to be the first
>> file each time, this is install from the same mirror that I used with
no
>> problems with file based, so it seems to still be something wrong with
my
>> disk setup?
>>
>> Anyways, it''s much closer now and past the first big
question/issue I had.
>>
>> If you have any ideas what caused the above error, I''d
appreciate it, if
>> not I''ll just hack away at it until it works.
>>
>> Thanks,
>>   Peter
>>
>>
>> On Sat, Jan 24, 2009 at 3:29 PM, Fajar A. Nugraha
<fajar@fajar.net>wrote:
>>
>>> On Sun, Jan 25, 2009 at 3:19 AM, Peter Hoose
<phoose@gmail.com> wrote:
>>> > I just created a LVM based vbd in my dom0, I want to use
>>> > this as my ''disk'' for my domU, which I would
create my partitions on.
>>> Is
>>> > this possible,
>>>
>>> Yes. For this purpose, you create one LV on dom0, map it to domU as
>>> xvda, and install domU like what you''d do with file-based
disk image.
>>>
>>> > or do I need to create a /boot, / and /swap on my domU and
>>> > share those with dom0 for it to access natively? IE: Does the
dom0 see
>>> this
>>> > partition as a disk that it can create partitions on, or does
it see it
>>> just
>>> > like a normal partition?
>>>
>>> I''m not quite sure what you mean, but you can do this :
>>> - create two LVs on dom0, map it to domU as xvda1 (for / ) and
xvda2
>>> (for swap). You don''t need a separate /boot.
>>> - do mkfs.ext3 and mkswap on dom0 directly on that LV (not creating
>>> partition on top of it)
>>> - populate domU''s filesystem (for example, by extracting
"templates"
>>> like the one from jailtime.org, or by copying from a working domU.)
>>> - create a suitable initrd
>>>
>>> Regards,
>>>
>>> Fajar
>>>
>>
>>
>

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On Sun, Jan 25, 2009 at 4:34 AM, Peter Hoose <phoose@gmail.com>
wrote:
> All good now,
Wow. You completed an install and test in just one hour, installing
from a HTTP public mirror? I envy your fast internet connection.

I was going to suggest that if you do HTTP-install often it might be
useful to create your own mirror, or simply use an install DVD/ISO to
create a HTTP install source. But in your case it seems you don''t need
one.
> and I definitely see a big performance improvement with
> partitions vs. tap:
>
> /dev/xvda:
>  Timing cached reads:   7856 MB in  2.00 seconds = 3936.95 MB/sec
>  Timing buffered disk reads:  306 MB in  3.00 seconds = 101.95 MB/sec
>
>
> Previously I was getting ~10MB/s with tap.
>
Oh my. And I was under the impression that tap: vs phy: today is the
same as using swapfile vs swap partition in terms of performance. I
guess I need to do some further testing.

Just one clarification though: Are you SURE you previously used non-sparse file?

Regards,

Fajar

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