search for: tcp_rmem

...88. This is less than the recommended value of 32768 bytes. You should increase the TCP receive buffer size for NFS on the client. Some googling around got me to check these values for TCP: # sysctl net.ipv4.tcp_mem net.ipv4.tcp_mem = 98304 131072 196608 # sysctl net.ipv4.tcp_rmem net.ipv4.tcp_rmem = 4096 87380 4194304 # sysctl net.ipv4.tcp_wmem net.ipv4.tcp_wmem = 4096 16384 4194304 So these seem fine to me (i.e., the max is greater than 32768). Is there an NFS (as opposed to TCP) setting I should be tweaking? Any ideas why the NetApp is is...

...e following settings in /etc/sysctl.conf file: # Custom Settings: net.ipv4.tcp_max_syn_backlog=2048 net.ipv4.tcp_fin_timeout=30 net.ipv4.tcp_keepalive_intvl=10 net.ipv4.tcp_keepalive_probes=7 net.ipv4.tcp_keepalive_time=1800 net.ipv4.tcp_max_tw_buckets=360000 net.ipv4.tcp_synack_retries=3 net.ipv4.tcp_rmem="4096 87380 16777216" net.ipv4.tcp_wmem="4096 87380 16777216" net.ipv4.tcp_mem="8388608 8388608 8388608" ---------errors----------- # sysctl -p [errors] error: unknown error 22 setting key 'net.ipv4.tcp_rmem' error: unknown error 22 setting key 'net.ipv4...

...e 25MB/sec from each. It starts off with a large burst like each can do 100MB/sec, but then in a couple of seconds, tapers off to the 15-40MB/sec until the dd finishes. Things I have tried (installed on the host and the guests) net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.ipv4.tcp_rmem = 4096 87380 16777216 net.ipv4.tcp_wmem = 4096 65536 16777216 net.ipv4.tcp_no_metrics_save = 1 net.ipv4.tcp_moderate_rcvbuf = 1 # recommended to increase this for 1000 BT or higher net.core.netdev_max_backlog = 2500 sysctl -w net.ipv4.tcp_congestion_control=cubic Any ideas? -- --tmac Re...

...- On /etc/grub.conf: kernel /vmlinuz-2.6.18-164.11.1.el5 ro root=LABEL=/ elevator=deadline quiet - On sysctl.conf # Special network params net.core.rmem_default = 8388608 net.core.wmem_default = 8388608 net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.ipv4.tcp_rmem = 1048576 4194304 16777216 net.ipv4.tcp_wmem = 1048576 4194304 16777216 # Disable netfilter on bridges. net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 # Virtual machines special kernel params vm.swappine...

Hi list (and happy new year), I'm experiencing some troubles using Samba (4.1.17 debian version) over VPN. Basically we've following setup : PC === LAN ===> VPN (WAN) ==== LAN ===> Samba file Server Copying big (say > 1MiB) files from PC to Samba file server almost always ends up with a NT_STATUS_IO_TIMEOUT error (or "a network error occured" if trying to copy from

Sysctl Values ------------------------------------------- net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.ipv4.tcp_rmem = 4096 87380 16777216 net.ipv4.tcp_wmem = 4096 65536 16777216 net.ipv4.tcp_window_scaling = 1 # vm.max-readahead = ? # vm.min-readahead = ? # HW Controler Off # max-readahead = 1024 # min-readahead = 256 # Memory over-commit # vm.overcommit_memory=2 # Memory to activate bdflush # vm.bdflush=&qu...

We use SMB to transfer large files (between 1GB and 5GB) from RedHat AS4 Content Storage servers to Windows clients with 6 DVD burners and robotic arms and other cool gadgets. The servers used to be Windows based, but we're migrating to RedHat for a host of reasons. Unfortunately, the RedHat Samba servers are about 2.5 times slower than the Windows servers. Windows will copy a 1GB file

...144 # Controls IP maximum receive buffer size (bytes) net.core.rmem_max = 262144 # Controls IP maximum send buffer size (bytes) net.core.wmem_max = 262144 # Controls TCP memory utilization (pages) net.ipv4.tcp_mem = 49152 65536 98304 # Controls TCP sliding receive window buffer (bytes) net.ipv4.tcp_rmem = 4096 87380 16777216 # Controls TCP sliding send window buffer (bytes) net.ipv4.tcp_wmem = 4096 65536 16777216 Ross S. W. Walker Information Systems Manager Medallion Financial, Corp. 437 Madison Avenue 38th Floor New York, NY 10022 Tel: (212) 328-2165 Fax: (212) 328-2125 WWW: http://www.medall...

...und_ratio = 1 vm.dirty_expire_centisecs = 1000 vm.dirty_writeback_centisecs = 100 vm.min_free_kbytes = 65536 net.core.rmem_default = 262144 net.core.rmem_max = 262144 net.core.wmem_default = 262144 net.core.wmem_max = 262144 net.core.netdev_max_backlog = 25000 net.ipv4.tcp_reordering = 127 net.ipv4.tcp_rmem = 4096 87380 16777216 net.ipv4.tcp_wmem = 4096 65536 16777216 net.ipv4.tcp_max_syn_backlog = 8192 net.ipv4.tcp_no_metrics_save = 1 The {r,w}mem_{max,default} values are twice what they were previously; changing these had no effect. The number of dirty pages is nowhere near the dirty_ratio when t...

...m doing some networking experiments over high BDP topologies. Right now the configuration is quite simple -- two Xen boxes connected via a dummynet router. The dummynet router is set to limit bandwidth to 500Mbps and simulate an RTT of 80ms. I''m using the following sysctl values: net.ipv4.tcp_rmem = 4096 87380 4194304 net.ipv4.tcp_wmem = 4096 65536 4194304 net.core.rmem_max = 8388608 net.core.wmem_max = 8388608 net.ipv4.tcp_bic = 0 (tcp westwood and vegas are also turned off for now) Now if I run 50 netperf flows lasting 80 seconds (1000RTTs) from inside a VM on one box...

I have a customer who is complaining about slow SFTP transfers over a long haul connection. The current transfer rate is limited by the TCP window size and the RTT. I looked at HPN-SSH, but that won't work because we don't control what software the peer is using. I was thinking about coding a much more modest enhancement that just does SO_RCVBUF for specific subsystems. In the interest

..._____________________ ifcfg-eth0: ETHTOOL_OPTS="-K ${DEVICE} tso on lro off; -G ${DEVICE} rx 128 tx 128" ______________________________________________ sysctl.conf: net.core.rmem_max = 65536 net.core.wmem_max = 65536 net.core.rmem_default = 32768 net.core.wmem_default = 32768 net.ipv4.tcp_rmem = 4096 32768 65536 net.ipv4.tcp_wmem = 4096 32768 65536 net.ipv4.tcp_mem = 4096 32768 65536 net.ipv4.udp_mem = 4096 32768 65536 net.ipv4.tcp_moderate_rcvbuf = 1 net.ipv4.tcp_sack = 1 net.ipv4.tcp_dsack = 1 ______________________________________________ smb.conf: socket options = TCP_NODELAY IPTOS...

..._OPTS="-K ${DEVICE} tso on lro off; -G ${DEVICE} rx 128 tx 128" > ______________________________________________ > > sysctl.conf: > > net.core.rmem_max = 65536 > net.core.wmem_max = 65536 > net.core.rmem_default = 32768 > net.core.wmem_default = 32768 > net.ipv4.tcp_rmem = 4096 32768 65536 > net.ipv4.tcp_wmem = 4096 32768 65536 > net.ipv4.tcp_mem = 4096 32768 65536 > net.ipv4.udp_mem = 4096 32768 65536 > net.ipv4.tcp_moderate_rcvbuf = 1 > net.ipv4.tcp_sack = 1 > net.ipv4.tcp_dsack = 1 > ______________________________________________ > > s...

OS: CentOS 5.0 x86. Hi, I am using CentOS 5.0 at home, ADSL ~16 Mbps/~1 Mbps Internet connection and my ping time to my ISP is 160-170 msec. When downloading something with Firefox, I am getting download speeds of about 100-180 KB/sec (for example when downloading SP2 of XP from MS server). Are the CentOS networking settings OK for this kind of latency, or do I have to change some settings?

...l -w net.ipv4.tcp_fin_timeout=30 /sbin/sysctl -w net.ipv4.tcp_keepalive_intvl=10 /sbin/sysctl -w net.ipv4.tcp_keepalive_probes=7 /sbin/sysctl -w net.ipv4.tcp_keepalive_time=1800 /sbin/sysctl -w net.ipv4.tcp_max_tw_buckets=360000 /sbin/sysctl -w net.ipv4.tcp_synack_retries=3 /sbin/sysctl -w net.ipv4.tcp_rmem="4096 87380 16777216" /sbin/sysctl -w net.ipv4.tcp_wmem="4096 87380 16777216" /sbin/sysctl -w net.ipv4.tcp_mem="8388608 8388608 8388608" --------------snip--------------- p.s. these are meant for a specific technology we use, so not sure if everyone reading would be...

i all I use linux as GiGE router and have 6 NIC on it Those days the NIC interrupt takes around 100% CPU but the system is 4G memroy and 8 CPU. I can't see any error packet in this NIC interface too After I block the udp, the %CPU drops. but the UDP only takes around 8M in general We use UDP traffic for voice. Do you have any suggestion ? increase the kernel parameter? Thank you so much

...size, in bytes kernel.shmmax = 68719476736 # Controls the maximum number of shared memory segments, in pages kernel.shmall = 4294967296 ########### add by operation V1.0 begin ############ net.ipv4.ip_local_port_range = 32768 65000 net.core.rmem_max = 8388608 net.core.wmem_max = 8388608 net.ipv4.tcp_rmem = 4096 87380 8388608 net.ipv4.tcp_wmem = 4096 65536 8388608 net.ipv4.tcp_max_syn_backlog = 8192 net.ipv4.tcp_window_scaling = 0 net.ipv4.tcp_sack = 0 net.ipv4.tcp_timestamps = 0 kernel.panic = 5 vm.swappiness = 51 ########### add by operation V1.0 end ############ net.bridge.bridge-nf-call-ip6tab...

...ew adjustments to the TCP settings on each system: echo 262144 > /proc/sys/net/core/rmem_max echo 262144 > /proc/sys/net/core/wmem_max echo 163840 > /proc/sys/net/core/rmem_default echo 163840 > /proc/sys/net/core/wmem_default echo "4096 163840 262144" > /proc/sys/net/ipv4/tcp_rmem echo "4096 163840 262144" > /proc/sys/net/ipv4/tcp_wmem echo "49152 163840 262144" > /proc/sys/net/ipv4/tcp_mem These, however, have only helped each of the transfer types performance-wise (FTP especially, smbfs wasn't really affected at all). Does anybody have any i...

Hi, I'm very interested in making SSH use UDP for large data chunks. Maybe you know FASP (https://en.wikipedia.org/wiki/Fast_and_Secure_Protocol), but that is proprietary, although the website says it's based upon open source methods. Is it possible to make openssh work with UDP for this purpose? Thanks in advance, Stef Bon

...if you had improved your situation, and if you did what you did. BTW here are some tweaks for network stack related stuff for Gig. sysctl -w net.core.rmem_max=8388608 sysctl -w net.core.wmem_max=8388608 sysctl -w net.core.rmem_default=65536 sysctl -w net.core.wmem_default=65536 sysctl -w net.ipv4.tcp_rmem='4096 87380 8388608' sysctl -w net.ipv4.tcp_wmem='4096 65536 8388608' sysctl -w net.ipv4.tcp_mem='8388608 8388608 8388608' sysctl -w net.ipv4.route.flush=1 Brian M. Duncan Katten Muchin Rosenman LLP 525 West Monroe Street Chicago IL 60661-3693 312-577-8045 brian.duncan@k...