From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roland Paterson-Jones Subject: Help/problems with blktap on xen-unstable Date: Wed, 20 Sep 2006 08:37:52 +0200 Message-ID: <4510E1C0.7020405@rolandpj.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Hi I've been trying to play with the new blktap support in xen-unstable. First, an observation - blktapctrl is pinned at 100% CPU: ----------------------------------------------------------------------------------------------------------------- top - 17:29:48 up 4 days, 2:02, 3 users, load average: 0.90, 1.01, 1.00 Tasks: 83 total, 3 running, 80 sleeping, 0 stopped, 0 zombie Cpu(s): 15.2% us, 34.9% sy, 0.0% ni, 49.9% id, 0.0% wa, 0.0% hi, 0.0% si Mem: 262356k total, 240936k used, 21420k free, 4832k buffers Swap: 917496k total, 96976k used, 820520k free, 67180k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3807 root 25 0 11040 508 400 R 99.9 0.2 0:17.56 blktapctrl 1 root 16 0 1744 124 92 S 0.0 0.0 0:00.87 init ------------------------------------------------------------------------------------------------------------------ Then, I am trying to follow the README to get an image file mounted via tap:aio in dom0 (as a precursor, or course, to using it for rootfs in a domU). So: [root@dom0-0-50-45-5d-59-aa tmp]# xm block-attach 0 tap:aio:/tmp/sparse.img /dev/xvda1 w 0 ... [root@dom0-0-50-45-5d-59-aa tmp]# xm block-list 0 Vdev BE handle state evt-ch ring-ref BE-path 51713 0 0 3 15 8 /local/domain/0/backend/tap/0/51713 But [root@dom0-0-50-45-5d-59-aa tmp]# mount /dev/xvda1 /mnt/tapaio mount: you must specify the filesystem type [root@dom0-0-50-45-5d-59-aa tmp]# mount -t ext3 /dev/xvda1 /mnt/tapaio mount: special device /dev/xvda1 does not exist And, indeed, there's no /dev/xvda1. Help! Roland