<div dir="ltr">Hello,<br><br>I'm wondering if anyone out there is doing tap:aio disk devices on a Xen HVM vm with any success. Please let me know if you are, and perhaps your version info and a config file snippet.<br>
<br>I've posted this to the xen-users list, and what I'm trying to do seems to be correct, works on Ubuntu, Debian, and XenSource; but it doesn't work on CentOS.<br>Here's the snippet from my config. More info in the message below:<br>
<pre>builder = "hvm"<br>kernel = "/usr/lib/xen/boot/hvmloader"<br>acpi = 0<br>apic = 0<br>device_model = "/usr/lib64/xen/bin/qemu-dm"<br>disk = [ "tap:aio:/xen/ausmsit05/ausmsit05.raw,hda,w", "tap:aio:/xen/iso/win2003r2_std_32bit_disk1of2.iso,hdc<br>
:cdrom,r" ]<br><br></pre><br><br><div class="gmail_quote">---------- Forwarded message ----------<br>From: <b class="gmail_sendername">-</b> <span dir="ltr"><<a href="mailto:debaan@gmail.com">debaan@gmail.com</a>></span><br>
Date: Thu, Aug 28, 2008 at 2:27 PM<br>Subject: HVM and tap:aio?<br>To: <a href="mailto:xen-users@lists.xensource.com">xen-users@lists.xensource.com</a><br><br><br><div dir="ltr">Hello,<br><br>I'm not able to use tap:aio disk definitions with my HVM domU's. Is this supposed to work on this version of Xen, or am I doing something wrong? <br>
I've tried everything I can think of. file: works, but not tap:aio: , and I understand that file: will cause OOMkiller if using NFS mounts and is deprecated.<br>
<br>Likewise, tap:aio: for cdrom does not allow me to boot off of cdrom; file: does work fine.<br><br>Furthermore, any time I use tap:aio, the bochs bios of the hvm domU shows the hard disk size as 0 MBytes.<br><br>Any disk definition that I use that has tap:aio: gives the result either (if tap:aio:/xen/foo/foo.img,xvda,w):<br>
<div style="margin-left: 40px;">Booting from Hard Disk...<br>Boot from Hard Disk failed: could not read the boot disk<br></div>or (if specifying tap:aio:/xen/foo/foo.img,hda,w)<br><div style="margin-left: 40px;">ata0 master: QEMU HARDDISK ATA-7 Hard-Disk (0 MBytes)<br>
Boot from Hard Disk failed: could not read the boot disk<br></div><br>Host: CentOS 5.2 x86_64, kernel <span>2.6.18-92.1.6.el5xen<br>Xen version: 3.1.2-92.1.6.el5<br>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 <br>
selinux: disabled for testing<br></span><span>domU: OS doesn't appear to matter; domU OS won't start loading at all.<br></span><br><span>disk lines I've tried:<br># disk recognized as 0/1 MB, can't install<br>
#disk = [ "tap:aio:/xen/ausmsit05/ausmsit05.raw,ioemu:sda,w", "file:/xen/iso/Win2003r2_std_32bit.iso,hdc:cdrom,r" ]<br>#disk = [ "tap:aio:/xen/ausmsit05/ausmsit05.raw,sda,w", "file:/xen/iso/Win2003r2_std_32bit.iso,hdc:cdrom,r" ]<br>
#disk = [ "file:/xen/ausmsit05/ausmsit05.raw,hda,w", "file:/xen/iso/Win2003r2_std_32bit.iso,hdc:cdrom,r" ]<br>#disk = [ "tap:aio:/xen/ausmsit05/ausmsit05.raw,sda1,w", ",hdc:cdrom,r" ]<br>
#disk = [ "tap:aio:/xen/ausmsit05/ausmsit05.raw,xvda,w", ",hdc:cdrom,r" ]<br>#disk = [ "tap:aio:/xen/ausmsit05/ausmsit05.raw,hda:ioemu,w", ",hdc:cdrom,r" ]<br>#disk = [ "tap:aio:/xen/ausmsit05/ausmsit05.raw,ioemu:hda,w", ",hdc:cdrom,r" ]<br>
#disk = [ "tap:aio:/xen/ausmsit05/ausmsit05.raw,ioemu:xvda,w", "phy:/dev/scd0,ioemu:xvdc:cdrom,r" ]<br># Boot from Hard Disk failed: could not read the boot disk<br>disk = [ "tap:aio:/xen/ausmsit05/ausmsit05.raw,hda,w", "tap:aio:/xen/iso/win2003r2_std_32bit_disk1of2.iso,hdc:cdrom,r" ]<br>
<br>in the last example, this is the output of xm block-list ausmsit05 --long<br>(768<br> ((backend-id 0)<br> (virtual-device 768)<br> (device-type disk)<br> (state 1)<br> (backend /local/domain/0/backend/tap/55/768)<br>
)<br>)<br>(5632<br> ((backend-id 0)<br> (virtual-device 5632)<br> (device-type cdrom)<br> (state 1)<br> (backend /local/domain/0/backend/tap/55/5632)<br> )<br>)<br>and this is from xend.log:<br>
<br><font size="1"><span style="font-family: courier new,monospace;">[2008-08-28 14:18:09 xend 3692] DEBUG (blkif:24) exception looking up device number for hda: [Errno 2] No suc</span><span style="font-family: courier new,monospace;">h file or directory: '/dev/hda'</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">[2008-08-28 14:18:09 xend 3692] DEBUG (DevController:110) DevController: writing {'backend-id': '0', 'virtual</span><span style="font-family: courier new,monospace;">-device': '768', 'device-type': 'disk', 'state': '1', 'backend': '/local/domain/0/backend/tap/55/768'} to /lo</span><span style="font-family: courier new,monospace;">cal/domain/55/device/vbd/768.</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">[2008-08-28 14:18:09 xend 3692] DEBUG (DevController:112) DevController: writing {'domain': 'ausmsit05', 'fro</span><span style="font-family: courier new,monospace;">ntend': '/local/domain/55/device/vbd/768', 'format': 'raw', 'dev': 'hda', 'state': '1', 'params': 'aio:/xen/a</span><span style="font-family: courier new,monospace;">usmsit05/ausmsit05.raw', 'mode': 'w', 'online': '1', 'frontend-id': '55', 'type': 'tap'} to /local/domain/0/b</span><span style="font-family: courier new,monospace;">ackend/tap/55/768.</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">[2008-08-28 14:18:09 xend 3692] DEBUG (blkif:24) exception looking up device number for hdc: [Errno 2] No suc</span><span style="font-family: courier new,monospace;">h file or directory: '/dev/hdc'</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">[2008-08-28 14:18:09 xend 3692] DEBUG (DevController:110) DevController: writing {'backend-id': '0', 'virtual</span><span style="font-family: courier new,monospace;">-device': '5632', 'device-type': 'cdrom', 'state': '1', 'backend': '/local/domain/0/backend/tap/55/5632'} to </span><span style="font-family: courier new,monospace;">/local/domain/55/device/vbd/5632.</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">[2008-08-28 14:18:09 xend 3692] DEBUG (DevController:112) DevController: writing {'domain': 'ausmsit05', 'fro</span><span style="font-family: courier new,monospace;">ntend': '/local/domain/55/device/vbd/5632', 'format': 'raw', 'dev': 'hdc', 'state': '1', 'params': 'aio:/xen/</span><span style="font-family: courier new,monospace;">iso/win2003r2_std_32bit_disk1of2.iso', 'mode': 'r', 'online': '1', 'frontend-id': '55', 'type': 'tap'} to /lo</span><span style="font-family: courier new,monospace;">cal/domain/0/backend/tap/55/5632.</span></font><br>
<br>Thank you in advance for any help you can offer.<br></span></div>
</div><br></div>