Performance problems with new DOSEMU server
Hi,
I've hit new problems.The 'old' server, running DOSEMU for multiple 'telnet' users (there can be 80+ simultaneous DOS sessions) is a 1GHz Pentium III based machine with 512 MB RAM....With that much users it was getting slow - linux load was hovering at ~8 all the time.
The 'new' server is a 2,83GHz quad core Xeon with 1GB RAM. It should be faster then the old one even for a single user, let-alone multiple users (theoretically, 4 DOS instances should be able to run in parallel without much influence to each other - one for each core, right?).
But test users report the OLD server is about 50 times (!!!) faster then the new one in some parts of their applications...I did not yet receive instructions to replicate what exactly they are doing so I could do tests on my own, but I'd like to do *something* in the meantime.
I tried to get some DOS benchmarks to run on each server, but I cant get any to run properly on both server - they either crash, lock-up or report non-sense results.
What could I use to compare the 'real life' speed of a DOS instance on both servers? For example - if it was linux, I'd compile the kernel and measure the time it took...
On the NEW server, a single DOS session is using 15 %CPU doing nothing, just sitting at the prompt. I can't do the same test on the OLD one now, because users left about 37 DOS sessions to run - but each get's about 6 %CPU (using 'top' to monitor CPU usage).
I left most of the 'dosemu.conf' alone, these are the only things I changed:
Quoted 7 lines
$_cpu = "80386"
$_hogthreshold = (10)
$_xms = (1024)
$_ems = (1024)
$_external_char_set = "cp437"
$_internal_char_set = "cp437"
$_layout = "us"
Quoted 8 lines
$_mouse_internal = (off)
$_lpt1 = "/usr/local/sbin/sendprint"
$_lpt2 = ""
$_pktdriver = (off)
$_vnet = "direct"
$_netdev = "eth0"
$_novell_hack = (on)
$_ipxsupport = (on)
Regards, Danilo
Quoted 1 line · Danilo Godec
But test users report the OLD server is about 50 times (!!!) faster
Is your new server running i386 or x86_64 Linux?
If it's running x86_64, that's the problem. Running i386 Linux allows your CPU to use a “Virtual86” mode, while x86_64 Linux requires that the whole thing be emulated in software which obviously takes more horsepower and therefore runs more slowly.
Signature · 6 lines
MELVILLE THEATRE ~ Melville Sask ~ http://www.melvilletheatre.com -- To unsubscribe from this list: send the line "unsubscribe linux-msdos" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
Quoted 10 lines · Frank Cox
Quoted 2 lines · Danilo Godec
But test users report the OLD server is about 50 times (!!!) faster
Is your new server running i386 or
x86_64Linux?If it's running
x86_64, that's the problem. Running i386 Linux allows your CPU to use a “Virtual86” mode, whilex86_64Linux requires that the whole thing be emulated in software which obviously takes more horsepower and therefore runs more slowly.
I had a hunch that x86_64 might create problems and since the server is not supposed to need more then 1GB of RAM, I decided to use i386:
Quoted 3 lines
# uname -a Linux dossrv3 2.6.31.8-0.1-desktop #1 SMP PREEMPT 2009-12-15 23:55:40 +0100 i686 i686 i386 GNU/Linux
Regards, Danilo
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