send_data.sh 的代码如下：
cd /home/pi/bin/cosm/
sed 's/\([0-9]*\.[0-9][0-9]\) \([0-9]*\.[0-9][0-9]\) \([0-9]*\.[0-9][0-9]\)\(.*\)/{"datastreams":[ {"id":"5min","current_value":"\1"},{"id":"10min","current_value":"\2"},{"id":"15min","current_value":"\3"} ]}/' /proc/loadavg > cosm-load.json
curl --request PUT --data-binary @cosm-load.json --header "X-ApiKey: -APIKEY" http://api.cosm.com/v2/feeds/95397?timezone=+8
VAL=`cat /sys/class/thermal/thermal_zone0/temp`
STR=`awk 'BEGIN{printf "{\"datastreams\":[ {\"id\":\"temp\",\"current_value\":\"%.1f\"} ] } ",'$VAL'/1000}'`
echo $STR > cosm_temp.json
curl --request PUT --data-binary @cosm_temp.json --header "X-ApiKey: -APIKEY" http://api.cosm.com/v2/feeds/95397?timezone=+8
pi的源列表: http://www.raspbian.org/RaspbianMirrors
测试了之后发现这个源在国内更新最快
http://mirror.devunt.kr/raspbian/raspbian/
更换源:
sudo vi /etc/apt/sources.list
更换为以下代码：
deb http://mirror.devunt.kr/raspbian/raspbian/ wheezy main contrib non-free rpi
外接磁盘绝对不能使用NTFS格式分区！速度非常慢
安装测试磁盘速度的软件：
sudo apt-get install hdparm
测试本地card的读写速度：
hdparm -Tt /dev/mmcblk0
pi@raspberrypi ~/downloads $ sudo hdparm -Tt /dev/mmcblk0
/dev/mmcblk0:
Timing cached reads: 210 MB in 2.02 seconds = 104.21 MB/sec
Timing buffered disk reads: 54 MB in 3.09 seconds = 17.45 MB/sec
pi@raspberrypi ~/downloads $ dd count=50 bs=1M if=/dev/zero of=~/test.img
50+0 records in
50+0 records out
52428800 bytes (52 MB) copied, 1.55218 s, 33.8 MB/s
测试外接硬盘的读写速度：
hdparm -Tt /dev/sda1
pi@raspberrypi ~/downloads $ sudo hdparm -Tt /dev/sda1
/dev/sda1:
Timing cached reads: 316 MB in 2.01 seconds = 157.46 MB/sec
Timing buffered disk reads: 62 MB in 3.03 seconds = 20.48 MB/sec
pi@raspberrypi ~/downloads $ dd count=50 bs=1M if=/dev/zero of=/media/usbdisk/test.img
50+0 records in
50+0 records out
52428800 bytes (52 MB) copied, 13.5962 s, 3.9 MB/s
将external disk 格式化成ext4
sudo mount -t ext4 /dev/sda1 /media/usbdisk
pi@raspberrypi / $ sudo dd count=50 bs=1M if=/dev/zero of=/media/usbdisk/test.img
50+0 records in
50+0 records out
52428800 bytes (52 MB) copied, 1.15549 s, 45.4 MB/s
bingo!!
过了这么些年，该改一改了。
比如外接盘用ntfs慢，那是因为仓库的ntfs-3g是旧版的(貌似是2014版).。以下源码安装2016版的ntfs-3g能达到的速度（外接盘是个非常垃圾的赠品u盘，而且旧版ntfs-3g只能几百Kb）: