Robert Nix wrote: "But, if one image starts doing compiles or compression
of large quantities of data, or any other CPU bound task, everyone will
suffer."
Actually you have a choice. If the compiles, etc. are relegated to a
compute server you can make it suffer rather than "everyone else", also, if
you cap the cpu given the guests you can minimize the intensity of t the
suffering when cpu heavy tasks occur, but it will go on for a longer period
of time. It's a matter of prioities and how you distribute work among
virtual machines. The beauty of Linux is that the "compute intense
server" can be a virtual or real machine, but it is still LInux. In
the past such a scheme using reeal machines would split the work between
ZOS and WIndows which is a lot more complex. We need to start thinking
about things like Grids of virtual and real servers.
Joe Temple
[EMAIL PROTECTED]
845-435-6301
"Nix, Robert P."
<Nix.Robert@mayo. To: [EMAIL PROTECTED]
edu> cc:
Sent by: Linux on Subject: Re: URGENT! really low
performance.
390 Port
<[EMAIL PROTECTED]
IST.EDU>
02/13/2003 04:01
PM
Please respond to
Linux on 390 Port
Mainframes do I/O exceptionally well, but when it comes to compute bound
tasks, they do very poorly. If you think about a tar operation, the
compression is a fairly compute-intensive operation.
We're running a 9672-R56 w/ one IFL. During our initial trial, we found the
IFL to be about the same as a 300 or 400mHz PC for compute-bound tasks. The
strength of the mainframe comes in for burst-type execution and I/O
throughput. Things like multiple web servers running in individual Linux
images. File serving. Anything where: A) The CPU isn't expected to be taxed
a great deal. and B) the CPU isn't going to be utilized for long periods of
time. This allows the CPU to be shared among a larger quantity of images,
giving all of them the impression of a dedicated box.
But, if one image starts doing compiles or compression of large quantities
of data, or any other CPU bound task, everyone will suffer.
----
Robert P. Nix internet: [EMAIL PROTECTED]
Mayo Clinic phone: 507-284-0844
RO-CE-8-857 page: 507-270-1182
200 First St. SW
Rochester, MN 55905
---- "Codito, Ergo Sum"
"In theory, theory and practice are the same,
but in practice, theory and practice are different."
> -----Original Message-----
> From: Alex Leyva [SMTP:[EMAIL PROTECTED]]
> Sent: Thursday, February 13, 2003 3:10 PM
> To: [EMAIL PROTECTED]
> Subject: URGENT! really low performance.
>
> Hi all, i have a problem, we have a z800, the configuration is:
> 1 cp 80 MIPS
> 1 IFL
> 8 Gb storage
> 3 partitions:
> -os/390 2.6
> -os/390 2.6
> -z/vm 4.3
> 840 gb (shark)
>
> the cp is dedicated to both os/390, and the ifl to z/vm, 2gb to
> both os/390, and 6 gb to z/vm.
>
> Redhat 7.2 as a z/vm guest:
>
> [root@linux1 root]# uname -a
> Linux linux1.xxx.xxx.xxx 2.4.9-38lvm #1 SMP mii feb 12 12:25:01 CST
> 2003 s390 unknown
> [root@linux1 s390]# cat /proc/cpuinfo
> vendor_id : IBM/S390
> # processors : 1
> bogomips per cpu: 630.78
> processor 0: version = FF, identification = 02900A, machine = 2066
> [root@linux1 s390]# cat /proc/meminfo
> total: used: free: shared: buffers: cached:
> Mem: 1045737472 364187648 681549824 0 15532032 317743104
> Swap: 409821184 0 409821184
>
>
> Default installation, the z/vm has one week installed:
>
> q cplevel
> z/VM Version 4 Release 3.0, service level 0201 (64-bit)
> Generated at 05/09/02 17:30:26 EST
> IPL at 02/07/03 12:13:53 EST
>
> when we make a tar -gzipping it- from a directory with 100Mb, we have
> that:
> -the hmc indicates that the ifl is at 99% utilization.
> -real time monitor indicates that the processor is at 99% utilization:
> | <USERID> %CPU %CP %EM ISEC PAG WSS RES UR PGES SHARE VMSIZE
TYP,CHR,STAT |
> | LINUX1 99 .15 99 4.4 .00 100K 100K .0 1 50%A 1G
VUS,QDS,DISP |
> | SYSTEM .08 .08 .00 .00 .00 0 5060 .0 536 ..... 2G SYS,
|
> | VMRTM .02 .01 .01 .63 .00 462 483 .0 0 3%A 32M
VUS,IAB,SIMW |
> -"top" at the linux shows:
> 30 processes: 27 sleeping, 3 running, 0 zombie, 0 stopped
> CPU states: 97.6% user, 2.3% system, 0.0% nice, 0.0% idle
> Mem: 1021228K av, 279636K used, 741592K free, 0K shrd, 14120K
buff
> Swap: 400216K av, 0K used, 400216K free 234992K
cached
>
> we apply some performance related commands like:
> set quickdsp linux1 on real
> set share linux1 relative 300 real
> set share linux1 absolute 50% real
>
> and the time went from 1m3.6s to 1m2.039s in the better case, the people
> from ibm (they are here yet) can give me an answer about the poor
> performance (i consider that its a poor performance, because a intel piii
> 128Mb RAM make the tar in about 28s), so i really dont know if this is
the
> real performance of linux under vm, if we are doing something wrong, or>
> what, when we bought the z800 they said that with this configuration we
> will be able to run about 200 virtual machinnes, maybe thats a fairly
> dream?
>
> Please, i accept any comments, sugestions, or anything that can help us.
>
> Thanks.
>
>
> --
> Alejandro Leyva Rabinovich.
> Jefe de la Unidad Departamental de Soporte Ticnico
> (Administracisn de Mainframe).
> Direccisn General de Informatica.
> Secretarma de Finanzas.
> Gobierno del Distrito Federal.
