Hello,

When is Raining Data going to support Red Hat 7.3 and 8.0?

The reason I ask is that all the new SERVERS that are coming out (i.e.
Pentium IV) have Intel Motherboard 8xx series. These all have on-board
Network, Video and Sound as options.

Red Hat 7.1 and Red Hat 7.2 does not support any of these boards 100%
and therefore the more machines I replace (or sell new), along with
other VAR's, are going to have more and more problems with Red Hat
7.1. RD are already aware of my comments regarding 7.1 anyway, and the
fact it was a "carbuncle" of a release in the first place.

Secondly, I have also "proved" that installing Red Hat 7.2 onto a
Pentium IV 2000 MHz actually runs slower than Red Hat 8.0 on the same
machine, with the same set-up. Considering Red Hat 8.0 has a "known"
greater overhead on a PC than previous Red Hat releases, it seems
quite apparent that Red Hat 7.xx does not support the Hard Disk /
Memory and Motherboards adequately for the new hardware platforms
being mass produced and therefore cannot be residing on these newer
platforms correctly.

Concerned

John

RD says they will support the newer kernels with D3 8.0.

Once again (look at the D3/Linux performance threads) the issue is
more with the KERNEL (and support from RD) than anything else.  The
real difference between the redhats is what version of the Kernel they
come with (along with what packages they wish to send).  I do not see
how a newer kernel (2.4.20) would run slower than the older kernel
(2.4.7) with the same hardware.  What could be the case the newer
RedHat loads more junk and/or uses different file systems (maybe ext2
vs ext3).  Plus the RD install script has some problems with the newer
redhat libraries.

The WHOLE problem here is that RD is playing a stalling game.  The BIG
problem with D3/Linux is that initially Linux did not allow direct
access to the disk.  Instead all disk I/O, even direct access to a
partition, went thu the linux flusher.  Well D3 has it's own flusher
and believes that it is in total control.  Since it is not, you end up
with conflicts and VM thrashing.  This only becomes a problem once you
get a bunch of users on the system.

Since D3 is competing/fighting with the Linux flusher, how the Linux
flusher does things affects D3's performance.  The Flusher in Linux
has been changed/modified many times in the 2.4 kernel series.  RD
felt that the 2.4.3 kernel (redhat 7.1) worked much better than the
redhat 7.2 kernel (2.4.7).  This is where RD stops.  They will not
help you if you have moved past 2.4.3 kernel.

I would recommend loading up a Redhat 7.1 machine.  Then upgrade your
kernel to the newest kernel keeping the older kernel.  Redhat will
allow you to boot back and forth between the kernels.  Unless you have
hardware that is plain NOT supported in the older kernels this should
work.  This way when you have issues you can jump back to the older
kernel for RD support.

- Patrick

Hi John,

If you are using the kernels from kernel.org, then yes, Linux will be
slower.

Load up Linux 7.1 or 7.2, then use the RedHat kernel source from RH7.3.
Recompile the kernel if you must, but you must retain the 'low latentcy
scheduler' and the option to use hight memory buffers for disk io. I am not
sure for D3, but for other apps that are heavy with disk io, the performance
improvement is dramatic.

But, I repeat, use the RedHat kernel source. RedHat have added the
performance options to the kernel that the kernel developers are still
squabling over. I also have found the .20 kernel to be slow in production,
I have gone back to the .18 RH kernel, much smoother and faster.

And just as final note, UniVision has been supporting RH 7.3 for some
time, plus integration with with a number of Linux tools like sendfax,
apache / tomcat, mgetty, as well as support for smp...sorry, I had to
mention it, I could not let an opportunity like this slide by.

Regards Barry

Interesting.  This shows again why RD (and probably any other Linux
software vendor) would have a tough time with Linux.  With the
frequency that new Kernels come out you would have to be testing your
product monthly.  Here we have kernel patches that could affect the
performance of the machine based on Redhat/Vs generic kernel, and even
Redhat 2.4.18 vs 2.4.20.  This shows that Linux is still very much a
Beta product.  The community is still throwing fixes/ideas at the wall
monthly that could affect adversly your software.  We are stuck
because while some of the kernel enhancements (like driver updates) we
need some other enhancements (like the scheduler/latency code) may
cause us issue.  I personally updated to the 2.4.20 kernel because it
had the latest 3ware driver installed.  I could have attempted to
compile/install the 3ware driver into the older kernel but it seemed
easier to upgrade the kernel.
- Patrick