zodiac home # dd if=/dev/zero of=ext4 bs=1024 count=200000             
200000+0 records in
200000+0 records out
204800000 bytes (205 MB) copied, 1.11217 s, 184 MB/s
zodiac home # dd if=ext4 of=/dev/null
400000+0 records in
400000+0 records out
204800000 bytes (205 MB) copied, 0.635323 s, 322 MB/s

# cd /dbdata/rfsdata/oclf
# # 200M
# dd if=/dev/zero of=ext4 bs=1024 count=200000             
200000+0 records in
200000+0 records out
204800000 bytes transferred in 79.867 secs (2564263 bytes/sec)
# dd if=ext4 of=/dev/null
400000+0 records in
400000+0 records out
204800000 bytes transferred in 346.247 secs (591485 bytes/sec)
# dd if=/dev/zero of=ext4 bs=1024 count=20000
20000+0 records in
20000+0 records out
20480000 bytes transferred in 31.912 secs (641764 bytes/sec)
# dd if=ext4 of=/dev/null
40000+0 records in
40000+0 records out
20480000 bytes transferred in 0.309 secs (66278317 bytes/sec)


# cd /dbdata/ext2data
# # 200M
# dd if=/dev/zero of=ext4 bs=1024 count=200000             
200000+0 records in
200000+0 records out
204800000 bytes transferred in 61.810 secs (3313379 bytes/sec)
# dd if=ext4 of=/dev/null
400000+0 records in
400000+0 records out
204800000 bytes transferred in 316.108 secs (647879 bytes/sec)
# #20M
# dd if=/dev/zero of=ext4 bs=1024 count=20000
20000+0 records in
20000+0 records out
20480000 bytes transferred in 0.542 secs (37,785,977 bytes/sec) <=== Delayed
write
# dd if=ext4 of=/dev/null
40000+0 records in
40000+0 records out
20480000 bytes transferred in 0.328 secs (62,439,024 bytes/sec) <=== Cached
read


# cd /mnt/sdcard
# # 20M test
# dd if=/dev/zero of=ext4 bs=1024 count=20000
20000+0 records in
20000+0 records out
20480000 bytes transferred in 3.033 secs (6,752,390 bytes/sec)
# dd if=ext4 of=/dev/null
40000+0 records in
40000+0 records out
20480000 bytes transferred in 0.336 secs (60,952,380 bytes/sec) 
# # 200M
# dd if=/dev/zero of=ext4 bs=1024 count=200000
200000+0 records in
200000+0 records out
204800000 bytes transferred in 165.051 secs (1,240,828 bytes/sec) 
#dd if=ext4 of=/dev/null
400000+0 records in
400000+0 records out
204800000 bytes transferred in 24.517 secs (8,353,387 bytes/sec) 

# # 第一次太慢，所以試第二次 200M
# dd if=/dev/zero of=ext4 bs=1024 count=200000
200000+0 records in
200000+0 records out
204800000 bytes transferred in 258.810 secs (791314 bytes/sec)