logs of BW and latency tests

bandwidth.log

78
96
100
114
125
135
163
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181
193
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196

dd_sequential_commands.sh

# varying block sizes here didn't affect bandwidth much
dd if=/dev/zero of=/dev/vdb bs=4M
dd if=/dev/vdb of=/dev/null bs=4M

ioping_latency_commands.sh

sudo ioping -i 0 -c 1000 /dev/vdb > 128k_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 256k_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 512k_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 1M_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 2M_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 4M_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 8M_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 16M_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 32M_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 64M_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 128M_latency.log
sudo ioping -i 0 -c 1000 /dev/vdb > 256M_latency.log

latencies.log

RA    ms
128 K	62.8
256 K	53.2
512 K	58.1
1 MB	51.9
2 MB	48.5
4 MB	44.4
8 MB	43
16 MB	43.2
32 MB	43.6
64 MB	42.1
128 MB	44
256 MB	43.6

read_ahead_commands.sh

sudo blockdev --setra 256 /dev/vdb    # 128KB, kernel default Ubuntu 12.04.3 LTS
sudo blockdev --setra 512 /dev/vdb
sudo blockdev --setra 1024 /dev/vdb
sudo blockdev --setra 2048 /dev/vdb
sudo blockdev --setra 4096 /dev/vdb
sudo blockdev --setra 8192 /dev/vdb
sudo blockdev --setra 16384 /dev/vdb
sudo blockdev --setra 32768 /dev/vdb
sudo blockdev --setra 65536 /dev/vdb
sudo blockdev --setra 131072 /dev/vdb
sudo blockdev --setra 262144 /dev/vdb # 128MB, performance matching write BW
sudo blockdev --setra 524288 /dev/vdb # 256MB, not a lot of performance increase if at all