On Fri, 14 Nov 2003 12:55:00 -0600, Jim Fischer
<jfischer_link5809@now.here.com> wrote:

>
>Here are some comments / suggestions:
>
>*) Various people have reported poor performance issues with various FTP
>programs (clients and/or servers) on various releases of <pick your
>favorite Linux distro>. So you might want to run some "Google Groups"
>searches on the Linux/Redhat newsgroups using keywords like "poor ftp
>performance" to see if you can locate some of these message threads.
>(
>http://www.google.com/advanced_group_search
>Newsgroups: *linux* *redhat*
>)

I have been doing this for the past few days. My problem is most
noticeable using FTP since FTP uses all available bandwidth, but a
simple ping also reveals the 10-20% packet loss, so an FTP specific
solution may not be in order. I could have picked a better subject
header, but it seems that many people are having this problem with
redhat 9.

>
>*) Even though the manufacturer of your RAID5 controller states that the
>"required" kernel version as '2.4.20-8', chances are that other kernel
>versions - and particularly later kernel versions - will work as good
>as, or even better than, the 2.4.20-8 release.

You would think so.

Actually, this device has very specific kernel support, unfortunately.
There has been talk of a partial source release of the driver which
would allow building the driver as a module or as part of a kernel,
but as of now, the driver is installed, prebuilt for specific kernels
only. This is a growing concern as there may be reasons that require
building a new kernel.

http://www.promise.com/support/downl...y=All&os=10 0

Promise really needs to get on the ball with Linux support.

>
>*) Multiple RH9 Linux 'kernel' RPMs can be installed on a single system
>at the same time, giving you the option to boot the computer into one of
>several different kernel versions. So you might consider downloading and
>installing the latest 'update' release of the RH9 'kernel' RPM.
>(ftp://ftp.redhat.com/pub/redhat/linux/updates/9/en/os)

Yes I know, I had 8 or 9 or so on my Mandrake system, Long live
lilo... but this doesnt help me in this case unless there are options
that I need to add or remove from my existing kernel version to fix
ppp.

>
>*) The Linux kernels that Red Hat provides contain Red Hat-specific
>"fixes" in the kernel code. So you might want to try downloading,
>building, and installing a stock Linux 2.4.20 (or later) kernel - i.e.,
>a kernel that hasn't been "fixed" by Red Hat - to see if a stock kernel
>works better. (http://www.kernel.org)
>

I would much rather use a plain vanilla kernel, but as of right now I
don't have the choice as explained above.

This is liable to be the fix, but unfortunately I cannot employ this
since the controller driver is forcing me to use a specific kernel.

I know better than to buy another one of these controllers for this
reason, but for now, all seems to be working well with the controller
itself and I need the storage capacity it is providing.

>*) The 'netfilter' firewall software (in the Linux kernel) has some
>kernel modules that provide protocol-specific support for connection
>tracking (ip_conntrack_*) and NAT (ip_nat_*). FTP is one of the
>protocols that requires these special connection tracking and NAT kernel
>modules - i.e., 'ip_conntrack_ftp' and 'ip_nat_ftp', respectively.
>
> [root]# modprobe ip_conntrack_ftp
> [root]# modprobe ip_nat_ftp
> [root]# lsmod | grep ^ip | sort
> [root]# find /lib/modules/ -name "ip_conntrack*"
> [root]# find /lib/modules/ -name "ip_nat_*"
>

I have never had to use the protocol specific modules before, but I do
not question you. I know they are there for a reason.

Additionally, I have the problem without iptables loaded. In other
words, PPP only from the linux box, ftp client from the linux box over
that ppp connection produces the poor performance.

>*) Are you using the latest-and-greatest release of the 'ppp' RPM? FWIW,
>here's the version that's currently installed on my RH9 Linux box:
>
> [root]# rpm -q ppp
> ppp-2.4.1-10
>

This is what I have installed.

>(n.b. I don't use PPP. So I can't offer any advice as to whether this is
>a stable/good release of the 'ppp' RPM or not.)
>
>FWIW, if the 'Fedora Core 1' distro has a newer version/release of the
>'ppp' RPM, you might consider downloading and then building the *SOURCE*
>RPM (SRPM) (.src.rpm) for the new release. You should be able to find
>the 'ppp' SRPM on Red Hat's FTP site (which seems to be off line today,
>along with Red Hat's web server <?>).

Building the latest PPP may not be a bad idea. It wouldnt be the
first time I have fixed smp related problems by building new binaries.

Any idea if pppd has any smp specific support or properties?

If this were a kernel specific problem, what methods are there for
diagnosing poor ppp performance aside from replacing the kernel?

How can I check if the IRQ's are being serviced properly?

How can I check if the pppd process is being serviced properly?

Charles