Hi all, After that I migrated my home sever from xen to kvm, I noticed very bad I/O performance, tried many combination versions/scsi-ide-virtio I got best by using kernel mod. 70 with userspace 69 and virtio.
Now I have upgraded to 2.6.26.2 and kvm-72, and the performance has dropped again. SO I ran some combinations of the kernel/user versions and it seem that kvm-69 is still the performance winnner for me Short summary of the numbers: - kvm-72(k) + kvm-69(u) + virtio ~= 56MB - 2.6.26.2(k) + kvm-69(u) + virtio ~= 48MB - kvm-72(k) + kvm-72(u) + virtio ~= 10MB - 2.6.26.2(k) + kvm-72(u) + virtio ~= 8MB My setup: - AMD Athlon(tm) X2 Dual Core Processor BE-2300 - 2 GB DDR - 2 SATA in RAID1, guests on lvm2 - Gentoo, no crazy CFLAGS (CFLAGS="-O2 -march=k8 -pipe -fomit-frame-pointer"), 32-bit PAE host and guests - kernel 2.6.26.2 and 2.6.25.9 (where stated) On host: # hdparm -Tt /dev/sda /dev/sda: Timing cached reads: 2046 MB in 2.00 seconds = 1023.79 MB/sec Timing buffered disk reads: 230 MB in 3.01 seconds = 76.53 MB/sec Numbers: module kvm-72/userspace KVM-72 --------------------------------------------------- ~ # hdparm -tT /dev/vda /dev/vda: Timing cached reads: 1538 MB in 1.99 seconds = 773.09 MB/sec Timing buffered disk reads: 38 MB in 3.07 seconds = 12.39 MB/sec ~ # hdparm -tT /dev/vda /dev/vda: Timing cached reads: 1532 MB in 1.99 seconds = 770.10 MB/sec Timing buffered disk reads: 26 MB in 3.18 seconds = 8.19 MB/sec ~ # time (dd if=/dev/vda of=/dev/null bs=`echo $(( 1024*1024 ))` count=1024 && sync) 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 103.673 s, 10.4 MB/s real 1m43.972s user 0m0.009s sys 0m3.804s module 2.6.26.2/userspace KVM-72 ---------------------------------------------------- ~ # hdparm -tT /dev/vda /dev/vda: Timing cached reads: 1446 MB in 1.99 seconds = 727.57 MB/sec Timing buffered disk reads: 26 MB in 3.15 seconds = 8.25 MB/sec ~ # hdparm -tT /dev/vda /dev/vda: Timing cached reads: 1506 MB in 1.99 seconds = 756.83 MB/sec Timing buffered disk reads: 24 MB in 3.12 seconds = 7.70 MB/sec ~ # time (dd if=/dev/vda of=/dev/null bs=`echo $(( 1024*1024 ))` count=1024 && sync) 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 133.183 s, 8.1 MB/s real 2m13.467s user 0m0.016s sys 0m3.637s module 2.6.26.2/userspace KVM-69 ---------------------------------------------------- ~ # hdparm -tT /dev/vda /dev/vda: Timing cached reads: 1706 MB in 1.99 seconds = 858.19 MB/sec Timing buffered disk reads: 124 MB in 3.06 seconds = 40.48 MB/sec ~ # hdparm -tT /dev/vda /dev/vda: Timing cached reads: 1690 MB in 1.99 seconds = 849.42 MB/sec Timing buffered disk reads: 152 MB in 3.06 seconds = 49.67 MB/sec ~ # time (dd if=/dev/vda of=/dev/null bs=`echo $(( 1024*1024 ))` count=1024 && sync) 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 22.7106 s, 47.3 MB/s real 0m22.950s user 0m0.014s sys 0m17.734s module KVM-72/userspace KVM-69 ---------------------------------------------------- ~ # hdparm -tT /dev/vda /dev/vda: Timing cached reads: 1732 MB in 1.99 seconds = 870.12 MB/sec Timing buffered disk reads: 252 MB in 3.03 seconds = 83.08 MB/sec ~ # hdparm -tT /dev/vda /dev/vda: Timing cached reads: 1742 MB in 1.99 seconds = 875.01 MB/sec Timing buffered disk reads: 334 MB in 3.03 seconds = 110.27 MB/sec ~ # time (dd if=/dev/vda of=/dev/null bs=`echo $(( 1024*1024 ))` count=1024 && sync) 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 19.1325 s, 56.1 MB/s real 0m19.310s user 0m0.013s sys 0m15.435s -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
