Solved:
I deleted the parameter "sync" in the root of the guest system and the
problem has been resolved. I know because the parameter "sync" appears
by default in the guest system template:
/etc/xen-tools/partitions.d/sample-server
Best regards,
Alvaro
2013/1/31 Alvaro <alvaro@haztelotumismo.net>:> Hello,
>
> This is my first post to the list, thanks in advance for the help. I
> started with xen recently and I have some problems.
>
> I have installed version xen 4.3.1 on debian wheezy.
> I have a problem of execution time between two guests. One of them
> takes longer to execute commands. And sometimes it seems that it
> freezes.
> Both machines are installed with LVM. The difference between them is
> that one only has the default installation (root-lvm-lvm & swap) and
> the other has four lvm in total.
>
> Both machines are created with the same command, and identical
> characteristics except lvm volumes.
>
> user1@deckard:~$ time sudo apt-get install apache2 -y
> Results:
> real 0m26.150s
> user 0m1.424s
> sys 0m0.868s
>
> user1@pris:~$ sudo apt-get install apache2 -y
> Results:
> real 6m42.202s
> user 0m2.052s
> sys 0m1.768s
>
> I have tried to do this test drive, but the results are the same. It
> seems it has to do with the execution:
> user1@deckard:~$ time dd if=/dev/zero of=./test bs=1024k count=5120
conv=fsync
> 5120+0 records in
> 5120+0 records out
> 5368709120 bytes (5.4 GB) copied, 122.405 s, 43.9 MB/s
> real 2m2.408s
> user 0m0.000s
> sys 0m6.968s
>
> user1@pris:~$ time dd if=/dev/zero of=./test bs=1024k count=5120 conv=fsync
> 5120+0 records in
> 5120+0 records out
> 5368709120 bytes (5.4 GB) copied, 122.234 s, 43.9 MB/s
> real 2m2.253s
> user 0m0.008s
> sys 0m7.148s
>
> I''ve also tried to recreate the machine has problems, but the
problem persists.
>
> Is there anyone who has thought something similar? In the domain logs
> xen and guests can not find anything.
>
> May be scheduler? I''ve "noop deadline [cfq]" in both.
>
> Thanks in advance.