Dear list, When writing to a logical volume (/dev/sys/test) directly through the device, I obtain a slow performance:
root@dom0-2:/dev/mapper# dd of=/dev/sys/test if=/dev/zero 4580305+0 records in 4580305+0 records out 2345116160 bytes (2.3 GB) copied, 119.327 s, 19.7 MB/s Making a file system on top of the LV, mounting it and write into a file is ok: root@dom0-2:/dev/mapper# mkfs.xfs /dev/sys/test root@dom0-2:/mnt# mount /dev/sys/test /mnt/lv root@dom0-2:/mnt# dd of=/mnt/lv/out if=/dev/zero 2647510+0 records in 2647510+0 records out 1355525120 bytes (1.4 GB) copied, 11.3235 s, 120 MB/s Furthermore, by accident I noticed that writing directly to the block device is oke when the LV is mounted (of course destroying the file system on it): root@dom0-2:/mnt# dd of=/dev/sys/test if=/dev/zero 3703375+0 records in 3703374+0 records out 1896127488 bytes (1.9 GB) copied, 15.4927 s, 122 MB/s Does anyone know what is going on? The configuration is as follows: Debian 6.0.2 Kernel 2.6.32-5-xen-amd64 Tests are on a partition on one physical disk Best regards, Dion Kant -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4e3f8173.5040...@concero.nl
