Hi,
we have several windows and linux guests which just perform fine.
but all our windows guests which are domaincontroller have big write issues. only write. read is fine.
the performance is about 2-10MByte/s ... 4K writes are 0.05Mbyte/s :-(
first i thought its all the windows 2008 guests... then i realized its also 2012... and then i found out that only certain machines have this problem.
on a 3 server install of an hosted exchange only the domaincontroroller & exchange database server is suuuuper slow. the other two machines perform good. (of course i also deaktivated all serveces to put the slow machine to idle to test)
on our terminal services machines we also have a good performance on the ts itself and a very bad write perfromance (read is almoust normal) on the domaincontroller and filserver (1 machine) - which was also mostly idle for testing...
this ONLY happens when we use LVM. when i add a virtual disk as a vmdk for example the write performance is ok for our kind of hardware (between 60 - 100MB writing)
adding another virtual disk as type LVM is slow again with just 5 MByte writing speed.
as example:
on the same host node & same LVM group i get for one win8K guest 100MB write and for the other win8k guest 4MB write - the host node has no load
adding a second virtual disk as vmdk gives me about 80MB write to the slow machine...
i played around with caching types-> does not improve the speed.
i tried cfq and deadline scheduler -> same slow speed.
i tried ide & virtio drivers -> same speed.
the only way to get more write speed is not to use LVM on this machines.
how can a litte difference on an windows setup have such a problem with LVM?
any ideas?
pveperf
CPU BOGOMIPS: 110391.12
REGEX/SECOND: 1036846
HD SIZE: 45.83 GB (/dev/disk/by-uuid/46ed2a90-07f7-4978-9e13-73ff56b7758f)
BUFFERED READS: 226.51 MB/sec
AVERAGE SEEK TIME: 8.16 ms
FSYNCS/SECOND: 2811.26
pveversion
pve-manager/3.1-24/060bd5a6 (running kernel: 2.6.32-26-pve)
hardware:
dual core xeons 6core
4 sata disks - 2 times raid1
3ware raidcontroller
thank you
philipp
we have several windows and linux guests which just perform fine.
but all our windows guests which are domaincontroller have big write issues. only write. read is fine.
the performance is about 2-10MByte/s ... 4K writes are 0.05Mbyte/s :-(
first i thought its all the windows 2008 guests... then i realized its also 2012... and then i found out that only certain machines have this problem.
on a 3 server install of an hosted exchange only the domaincontroroller & exchange database server is suuuuper slow. the other two machines perform good. (of course i also deaktivated all serveces to put the slow machine to idle to test)
on our terminal services machines we also have a good performance on the ts itself and a very bad write perfromance (read is almoust normal) on the domaincontroller and filserver (1 machine) - which was also mostly idle for testing...
this ONLY happens when we use LVM. when i add a virtual disk as a vmdk for example the write performance is ok for our kind of hardware (between 60 - 100MB writing)
adding another virtual disk as type LVM is slow again with just 5 MByte writing speed.
as example:
on the same host node & same LVM group i get for one win8K guest 100MB write and for the other win8k guest 4MB write - the host node has no load
adding a second virtual disk as vmdk gives me about 80MB write to the slow machine...
i played around with caching types-> does not improve the speed.
i tried cfq and deadline scheduler -> same slow speed.
i tried ide & virtio drivers -> same speed.
the only way to get more write speed is not to use LVM on this machines.
how can a litte difference on an windows setup have such a problem with LVM?
any ideas?
pveperf
CPU BOGOMIPS: 110391.12
REGEX/SECOND: 1036846
HD SIZE: 45.83 GB (/dev/disk/by-uuid/46ed2a90-07f7-4978-9e13-73ff56b7758f)
BUFFERED READS: 226.51 MB/sec
AVERAGE SEEK TIME: 8.16 ms
FSYNCS/SECOND: 2811.26
pveversion
pve-manager/3.1-24/060bd5a6 (running kernel: 2.6.32-26-pve)
hardware:
dual core xeons 6core
4 sata disks - 2 times raid1
3ware raidcontroller
thank you
philipp