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some benchmarking

Testimonials / What ressources to benchmark and how?
  • network-i/o: netcat -l -p 2222 >/dev/null & dd if=/dev/zero bs=512M count=10 |netcat 2222
  • disk i/o random: iozone, bonnie++
  • disk i/o block: time bash -c 'dd if=/dev/zero of=testfile bs=512M count=4; sync;'
  • ram i/o, pure userspace/cpu-power: kernelunzipping to ram, kernelcompilation in ram, ubench
  • hvm/nas/net: domU is in a file on attached nfs in HVM-mode, no paradrivers
  • hvmp/nas/net: domU is in a file on attached nfs in HVM-mode, paradrivers
  • para/nas/net: domU is in a file on attached nfs
  • para/lvm/san: domU is in a logical volume on SAN
  • para/file/ram: domU is in a file on a dom0-ram
  • para/lvm/iscsi:domU is in a logical volume on iscsi
  • para/xfs/iscsi:domU is in a file on an xfs-filesystem on iscsi
  • para/lvm/disc: domU is in a logical volume on the local disk of dom0
  • para/xfs/disc: domU is in a file on an xfs-filesystem on the local disk of dom0
  • dom0/xfs/disc: tests on the dom0 (using internal sas-discs)
  • bare/xfs/disc: bare metal linux without xen-kernel
hvm hvmp paravirtualized domU dom0 bare
nas nas nas lvm file lvm xfs lvm xfs xfs xfs
net net net san ram iscsi iscsi disc disc disc disc
network throughput domU→dom0 in Mb/s 7 84 230 229 231 221 226 230 231 246 344
network throughput dom0→domU in Mb/s 21 122 97 110 96 93 93 98 97 246 344
latency for icmp domU↔dom0 in ms .2 .1 .1 .1 .1 .1 .1 .1 .1 .03 .01
time tar xjf linux-2.6.19.tar.bz2 in s 17 14 25 18 18 17 15 13 18 16 13
time make -j8 bzImage modules (real in s) 1241 1257 561 547 560 555 556 559 559 593 465
time it takes to write a 2GB blockfile 17 72 40 16 8 42 48 139 65 36 32
  • OS was SuSE SLES10SP1 amd64 with current patches as of september 2007
  • kernel extraction and compiling was done in ram of the domU
  • kernel compilation was done w/ 4 cpus pinned to the domU/dom0 and warm cache, 8GB ram
  • notice: cant test how tap:aio instead of file behaves since sles10sp1 xen doesnt support it apparently
  • here i used the disc the domU was running on for testing. Below is a test for a disc without partitiontable/filesystem, just blockdevice handed through.
  • conclusion: many values dont make much sense. random i/o also hasnt been tested yet. One should benchmark having a specific environment in mind.

some more benchmarking

What was benched here: raw i/o throughput. Just wanted to see how much performance-overhad a xen-domU has compared to the dom0 under it. Bevore testing i filled up on a host a partition on local harddiscs with data, and compared this to filling up a lvm-volume: both values are the same as expected. Commands used for testing now:

# in dom0:
time bash -c 'dd if=/dev/zero of=/dev/system/lv_ch_perftest bs=512M count=16; sync;'
# this writes 8GB of data to the logical volume and syncs it. 

# in domU, after handing the lv_ch_perftest over as xvdb:
time bash -c 'dd if=/dev/zero of=/dev/xvdb bs=512M count=16; sync;'
software/xen/benchmarking.txt · Last modified: 2021/03/23 12:22 (external edit)