Re: Supermicro X8DTH-6: Only ~250MiB/s from RAID<->RAID over 10GbE?

Justin Piszcz
2011-02-06T17:52:57Z

On Feb 6, 2011, at 11:55 AM, Zdenek Kaspar <zkaspar82@gmail.com> wrote:

> Dne 6.2.2011 14:46, Justin Piszcz napsal(a):
>>
>>
>> On Sun, 6 Feb 2011, Justin Piszcz wrote:
>>
>>>
>>>
>>> On Sat, 5 Feb 2011, Stan Hoeppner wrote:
>>>
>>>> Justin Piszcz put forth on 2/5/2011 7:08 PM:
>>>>
>>
>>
>> Hi,
>
> Hi, just few comments for maximal throughput..
>
>> 1. Defaults below:
>> sysctl -w net.core.wmem_max=131071
>> sysctl -w net.core.rmem_max=131071
>> sysctl -w net.core.wmem_default=118784
>> sysctl -w net.core.rmem_default=118784
>> sysctl -w net.core.optmem_max=20480
>> sysctl -w net.ipv4.igmp_max_memberships=20
>> sysctl -w net.ipv4.tcp_mem="379104 505472 758208"
>> sysctl -w net.ipv4.tcp_wmem="4096 16384 4194304"
>> sysctl -w net.ipv4.tcp_rmem="4096 87380 4194304"
>> sysctl -w net.ipv4.udp_mem="379104 505472 758208"
>> sysctl -w net.ipv4.udp_rmem_min=4096
>> sysctl -w net.ipv4.udp_wmem_min=4096
>> sysctl -w net.core.netdev_max_backlog=1024
>
> sysctl net.ipv4.tcp_timestamps=0
>
>> 2. Optimized settings, for > 800MiB/:
>>
>> # for 3ware raid, use 16384 readahead, > 16384 readahead, no improvement
>> blockdev --setra 16384 /dev/sda
>
> elevator=deadline
>
>> # not sure if this helps much
>> ethtool -K eth0 lro on
>
> Maybe try to _disable_ NIC offloads functions, sometimes its contra
> productive (with enough CPU power, but I doubt on 2 socket box) + check
> irqbalance..
>
> If you have connection just between machines try the biggest possible MTU.
>
>> # seems to get performance > 600-700MiB/s faster
>> sysctl -w net.core.wmem_max=4194304
>> sysctl -w net.core.rmem_max=4194304
>> sysctl -w net.core.wmem_default=4194304
>> sysctl -w net.core.rmem_default=4194304
>> sysctl -w net.core.optmem_max=20480
>> sysctl -w net.ipv4.igmp_max_memberships=20
>> sysctl -w net.ipv4.tcp_mem="4194304 4194304 4194304"
>> sysctl -w net.ipv4.tcp_wmem="4194304 4194304 4194304"
>> sysctl -w net.ipv4.tcp_rmem="4194304 4194304 4194304"
>> sysctl -w net.ipv4.udp_mem="4194304 4194304 4194304"
>> sysctl -w net.ipv4.udp_rmem_min=4096
>> sysctl -w net.ipv4.udp_wmem_min=4096
>> sysctl -w net.core.netdev_max_backlog=1048576
>>
>> # the main option that makes all of the difference, the golden option
>> # is the rszie and wsize of 1megabyte below:
>> 10.0.1.4:/r1 /nfs/box2/r1 nfs
>> tcp,bg,rw,hard,intr,nolock,nfsvers=3,rsize=1048576,wsize=1048576 0 0
>>
>> CPU utilization:
>> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
>> 2069 root 20 0 18640 1304 688 R 91 0.0 0:15.50 cp
>> 703 root 20 0 0 0 0 S 25 0.0 2:46.95 kswapd0
>>
>> With a single copy I get roughly 700-800MiB/s:
>>
>> Device eth0 [10.0.1.3] (1/1):
>> ================================================================================
>>
>> Incoming:
>> ###################### #################### ####
>> ###################### #################### ####
>> ###################### #################### ####
>> ###################### #################### ####
>> ###################### #################### ####
>> ###################### #################### #### Curr: 808.71 MByte/s
>> ###################### #################### #### Avg: 706.11 MByte/s
>> ###################### #################### #### Min: 0.00 MByte/s
>> ###################### #################### #### Max: 860.17 MByte/s
>> ###################### #################### #### Ttl: 344.70 GByte
>>
>> With two copies I get up to 830-850MiB/s:
>>
>> Device eth0 [10.0.1.3] (1/1):
>> ================================================================================
>>
>> Incoming:
>> ############################################ ####
>> ############################################ ####
>> ############################################ ####
>> ############################################ ####
>> ############################################ ####
>> ############################################ #### Curr: 846.61 MByte/s
>> ############################################ #### Avg: 683.14 MByte/s
>> ############################################ #### Min: 0.00 MByte/s
>> ############################################ #### Max: 860.17 MByte/s
>> ############################################ #### Ttl: 305.71 GByte
>>
>> Using a 4MiB r/w size with NFS improves performance to sustain > 750MiB/s
>> a little better I think:
>> 10.0.1.4:/r1 /nfs/box2/r1 nfs
>> tcp,bg,rw,hard,intr,nolock,nfsvers=3,rsize=4194304,wsize=4194304 0
>
> What about using UDP ?
>
>> Anyhow, roughly 750-850MiB/s it would be nice to get 1Gbyte/sec but I guess
>> the kerrnel (or my HW, CPU not fast enough) is not there yet.
>>
>> Also found a good doc from RedHat:
>> http://www.redhat.com/promo/summit/2008/downloads/pdf/Thursday/Mark_Wagner.pdf
>>
>>
>> Justin.
>>
>
> HTH, Z.

Thx for suggestions, I have tried some of those additional optimizations in the past but they did not seem to give increases in performance, but will revisit them if I have time, thanks.

UDP seemed to hit and stay at 650MiB/s.

Justin.