LinuxQuestions.org - Slow transfer speeds

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Slow transfer speeds

I've been experiencing slow transfer speeds on my server for quite some time now and I have no clue what is causing it (or how to further debug the problem). Transfer speeds both download and upload are both very slow at around ~50kb/s.

I've ran some wget tests, and found that transfer speeds to other servers within the datacenter are normal. The slow speeds only occur from transfers going in and out of the DC. I've tried disabling firewalls, tweaking the TCP window sizes and the slow speeds still occur.

So, any thing I can do to help further debug this issue to find out whether it is a network issue, something on my box etc?

Any input greatly appreciated :)

may be you reach your limit as a result of traffic grow

Quote:

Originally Posted by Stephan_Craft (Post 3611548)

may be you reach your limit as a result of traffic grow

Well, I've contacted my DC and according to them there isn't a network problem on their side so it is either a config issue on my box or there is actual something wrong with the network.

post here your sysctl.conf

Quote:

Originally Posted by Stephan_Craft (Post 3611552)

post here your sysctl.conf

Server has an Intel C2D with 2GB RAM

Code:

# Kernel sysctl configuration file for Red Hat Linux

#

# For binary values, 0 is disabled, 1 is enabled.  See sysctl(8) and

# sysctl.conf(5) for more details.



# Controls IP packet forwarding

net.ipv4.ip_forward = 0

net.ipv4.tcp_wmem = 4096 65536 16777216

net.ipv4.tcp_rmem = 4096 87380 16777216

net.core.wmem_default = 2097152

net.core.wmem_max = 16777216

net.core.rmem_max = 16777216

net.core.rmem_default = 2097152

net.core.wmem_default = 2097152

net.ipv4.tcp_mem= 8388608 8388608 8388608



# Controls source route verification

net.ipv4.conf.default.rp_filter = 1

net.ipv4.conf.all.rp_filter = 1

# Do not accept source routing

net.ipv4.conf.default.accept_source_route = 0

net.ipv4.tcp_fin_timeout = 15

net.ipv4.tcp_keepalive_time = 1800

net.ipv4.tcp_window_scaling = 1

net.ipv4.tcp_sack = 1

net.ipv4.tcp_timestamps = 1

net.ipv4.tcp_max_syn_backlog = 2048

# Controls the System Request debugging functionality of the kernel

kernel.sysrq = 0

net.ipv4.tcp_max_orphans = 131072

# Controls whether core dumps will append the PID to the core filename

# Useful for debugging multi-threaded applications

kernel.core_uses_pid = 1



# Controls the use of TCP syncookies

net.ipv4.tcp_syncookies = 1



# Controls the maximum size of a message, in bytes

kernel.msgmnb = 65536



# Controls the default maxmimum size of a mesage queue

kernel.msgmax = 65536



# Controls the maximum shared segment size, in bytes

kernel.shmmax = 4294967295



# Controls the maximum number of shared memory segments, in pages

kernel.shmall = 268435456

net.ipv4.netfilter.ip_conntrack_tcp_timeout_syn_recv = 30

net.ipv4.netfilter.ip_conntrack_tcp_timeout_time_wait = 30

net.ipv4.netfilter.ip_conntrack_tcp_timeout_fin_wait = 30

net.ipv4.netfilter.ip_conntrack_tcp_timeout_close_wait = 30

kernel.panic=5

net.ipv4.tcp_max_syn_backlog = 2048

net.netfilter.nf_conntrack_max = 50485760

net.nf_conntrack_max = 50485760

net.ipv4.netfilter.ip_conntrack_max = 50485760

net.ipv4.ip_conntrack_max = 262144

looks fine to me...

try to turn off your Firewall and SELinux
you can also try
iptables -F

Quote:

Originally Posted by Stephan_Craft (Post 3611561)

looks fine to me...

try to turn off your Firewall and SELinux
you can also try
iptables -F

Yeah SELinux is disabled already and tried disabling firewalls problem still occurs, hmm. I'm not sure what else locally on my box could be causing slow speeds, I'm starting to think it is a network issue or a hardware issue on my box.

Quote:

Originally Posted by lew (Post 3611565)

I'm starting to think it is a network issue

may be your server connected to switch(with other servers) or something, and it reached the 100MB limit

Quote:

Originally Posted by lew (Post 3611417)

Transfer speeds both download and upload are both very slow at around ~50kb/s.

Quote:

Originally Posted by Stephan_Craft (Post 3611570)

may be your server connected to switch(with other servers) or something, and it reached the 100MB limit

What am I missing? -- How can a 100MB (= 1,024,000kb) limit cause 50kb speeds?