Poor write performance with physical disk on DomainU freebsd

Poor write performance with physical disk on DomainU freebsd

[lepton]

I get freebsd xen port from http://www.fsmware.com/xenofreebsd/5.3/

After I get it to work, I think using a loop file is slow. So I decided to
move all files to a physical disk.
I changed my xen configuration file, add a 'phys:hda2,hda2,w' in my
disks configration.

then in freebsd, I newfs /dev/xbd1, mount it, and use

tar -cvpf- /|(cd /mnt;tar -xf-) to move files from loop device to
physical device.

I found the tar process will block (use ps, I will see it is in 'D'
status) after some work.

I have tried async mount and softupdate, the result is same.
I tried dump and restore too, the result is same.

And the system whil not response to remote ssh login when tar block.
But it will reply to ping.

Is this a known problem to freebsd on xen?

Re: Poor write performance with physical disk on DomainU freebsd

[Kip Macy]

There are some fixes to the block driver that may not be in that build. 
I won't get a chance to look into it until next week.

                     -Kip


On 8/5/05, lepton <ytht.net@gmail.com> wrote:
> I get freebsd xen port from http://www.fsmware.com/xenofreebsd/5.3/
> 
> After I get it to work, I think using a loop file is slow. So I decided to
> move all files to a physical disk.
> I changed my xen configuration file, add a 'phys:hda2,hda2,w' in my
> disks configration.
> 
> then in freebsd, I newfs /dev/xbd1, mount it, and use
> 
> tar -cvpf- /|(cd /mnt;tar -xf-) to move files from loop device to
> physical device.
> 
> I found the tar process will block (use ps, I will see it is in 'D'
> status) after some work.
> 
> I have tried async mount and softupdate, the result is same.
> I tried dump and restore too, the result is same.
> 
> And the system whil not response to remote ssh login when tar block.
> But it will reply to ping.
> 
> Is this a known problem to freebsd on xen?
> 
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> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>