Hello, My configuration: Server DELL 2860 Intel(R) Xeon(R) CPU X3230 @ 2.66GHz (Quad Core) 8GB of memory 2 x SAS 15000 300G0 RAID 0 hardware SLES 10 SP2 Kernel 2.6.16.60-0.21-xen i have one volume group vg0 ( whith one PV, the two disks in raid0) whith many lvm I am very surprise about LVM2 performance when a snapshot is done. Write speed on the Original volume is very bad when a snaphot is active... For exemple: Speed on /dev/vg0/test when there is NO snapshot : suse2:~ # dd if=/dev/zero of=/dev/vg0/test bs=2M count=400 400+0 records in 400+0 records out 838860800 bytes (839 MB) copied, 6.42741 seconds, 131 MB/s Speed on /dev/vg0/test when there is one snapshot of this original volume : suse2:~ # lvremove --force /dev/vg0/test3.snap Logical volume "test3.snap" successfully removed suse2:~ # dd if=/dev/zero of=/dev/vg0/test bs=2M count=400 400+0 records in 400+0 records out 838860800 bytes (839 MB) copied, 6.42741 seconds, 131 MB/s suse2:~ # lvcreate -s -L1G -ntest.snap /dev/vg0/test Logical volume "test.snap" created suse2:~ # dd if=/dev/zero of=/dev/vg0/test bs=2M count=400 400+0 records in 400+0 records out 838860800 bytes (839 MB) copied, 204.862 seconds, 4.1 MB/s Speed on /dev/vg0/test when there is 2 snapshots of this original volume : suse2:~ # lvcreate -s -L1G -ntest1.snap /dev/vg0/test Logical volume "test1.snap" created suse2:~ # lvcreate -s -L1G -ntest2.snap /dev/vg0/test Logical volume "test2.snap" created suse2:~ # lvremove /dev/vg0/test2.snap Do you really want to remove active logical volume "test2.snap"? [y/n]: y Logical volume "test2.snap" successfully removed suse2:~ # dd if=/dev/zero of=/dev/vg0/test bs=2M count=400 400+0 records in 400+0 records out 838860800 bytes (839 MB) copied, 270.928 seconds, 3.1 MB/s Do you know some elements about tunning performance?,? Performances are disastrous when a snaphot is active Could you give your speed result? and your amelioration?? ps:Results are the same whithout Kernel Xen and whith a kernel more recent (2.6.24.2) <table> <tr> <td>Cordialement, </table> <table> <tr> <td colspan=2> <div align=center><img src=cid:_1_0AC6134C0AC60F78004C0616C1257460></div> <tr> <td>MARTINEAU Antony Service informatique Assistant informatique LIPPI Management <td>La Fouillouse 16440 Mouthiers sur Boheme Tel.: 05.45.67.34.35 Courriel: <a href=mailto:antony.martineau@lippi.fr>antony.martineau@lippi.fr</a> <a href=http://www.lippi.fr/>http://www.lippi.fr</a> </table> <img src=http://www.lippi.fr/img/eco.jpg> Ce message et toutes les pieces jointes sont etablis a l'attention exclusive de ses destinataires et sont strictement confidentiels. <a href=http://www.lippi.fr/disclaimer.php>Pour en savoir plus cliquer ici</a> This message and any attachments are confidential to the ordinary user of the e-mail address to which it was addressed and may also be privileged. <a href=http://www.lippi.fr/disclaimer.php>More information</a>