On a FreeBSD 8.0-RELEASE/amd64 system with a Supermicro X7SPA-H board using an Intel gigabit nic with the em driver, running on top of a ZFS mirror, I was seeing a strange issue. Local reads and writes to the pool easily saturate the disks with roughly 75mb/s throughput, which is roughly the best these drives can do. However, working with Samba, writes to a share could easily pull off 75mb/s and saturate the disks, but reads off a share were resulting in rather pathetic 18mb/s throughput.
I found a threadon the FreeBSD forums (http://forums.freebsd.org/showthread.php?t=9187) and followed the suggested advice. I rebuilt Samba with AIO support, kldloaded the aio module and made the following changes to my smb.conf From: socket options=TCP_NODELAY To: socket options=SO_RCVBUF=131072 SO_SNDBUF=131072 TCP_NODELAY min receivefile size=16384 use sendfile=true aio read size = 16384 aio write size = 16384 aio write behind = true dns proxy = no[/CODE] This showed a very welcome improvement in read speed, I went from 18mb/s to 48mb/s. The write speed remained unchanged and was still saturating the disks. Now I tried the suggested sysctl tunables: atombsd# sysctl net.inet.tcp.delayed_ack=0 net.inet.tcp.delayed_ack: 1 -> 0 atombsd# sysctl net.inet.tcp.path_mtu_discovery=0 net.inet.tcp.path_mtu_discovery: 1 -> 0 atombsd# sysctl net.inet.tcp.recvbuf_inc=524288 net.inet.tcp.recvbuf_inc: 16384 -> 524288 atombsd# sysctl net.inet.tcp.recvbuf_max=16777216 net.inet.tcp.recvbuf_max: 262144 -> 16777216 atombsd# sysctl net.inet.tcp.sendbuf_inc=524288 net.inet.tcp.sendbuf_inc: 8192 -> 524288 atombsd# sysctl net.inet.tcp.sendbuf_max=16777216 net.inet.tcp.sendbuf_max: 262144 -> 16777216 atombsd# sysctl net.inet.tcp.sendspace=65536 net.inet.tcp.sendspace: 32768 -> 65536 atombsd# sysctl net.inet.udp.maxdgram=57344 net.inet.udp.maxdgram: 9216 -> 57344 atombsd# sysctl net.inet.udp.recvspace=65536 net.inet.udp.recvspace: 42080 -> 65536 atombsd# sysctl net.local.stream.recvspace=65536 net.local.stream.recvspace: 8192 -> 65536 atombsd# sysctl net.local.stream.sendspace=65536 net.local.stream.sendspace: 8192 -> 65536 This improved the read speeds a further tiny bit, now I went from 48mb/s to 54mb/s. This is it however, I can't figure out how to increase Samba read speed any further. Any ideas? _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
