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[rds100]

root@raspberrypi:~# dd if=/dev/zero of=test bs=4k count=64k conv=fdatasync
65536+0 records in
65536+0 records out
268435456 bytes (268 MB) copied, 11.8919 s, 22.6 MB/s
 

Here is what USB devices are there:

root@raspberrypi:~# lsusb
Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp.
Bus 001 Device 004: ID 125f:312b A-DATA Technology Co., Ltd. Superior S102 Pro
 

Here is what "mount" looks like:

root@raspberrypi:~# mount
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,relatime,size=10240k,nr_inodes=61617,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=49756k,mode=755)
/dev/sda2 on / type ext4 (rw,noatime,data=ordered)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /run/shm type tmpfs (rw,nosuid,nodev,noexec,relatime,size=99500k)
/dev/sda1 on /boot type ext2 (rw,noatime,errors=continue,user_xattr,acl)
tmpfs on /tmp type tmpfs (rw,relatime)
 

 

[splitice]

Thanks thats interesting unfortunately I don't have a test device currently would be interesting to fiddle.

Anyway Ill keep an eye on this

 

[willie]

The speed problem with both normal sd cards and cheap usb sticks is with small random writes.  They are just not built for that, they're basically sequential devices made for file storage, and random throughput is completely terrible.  You can't really use them as SSD if you're running something like a database.  There are some fancy USB sticks that are built like SSD's and are very fast, but also quite expensive.  The Beaglebone Black has some on-board flash that might get around this problem, though its capacity its limited (2gb iirc).

 

[rds100]

One should not put a busy database on a Raspberry Pi anyway It's for toying, mostly.

For serious loads, get a real server with a real SSD.

 

[HalfEatenPie]

root@rpi:/home# dd if=/dev/zero of=test bs=4k count=64k conv=fdatasync
65536+0 records in
65536+0 records out
268435456 bytes (268 MB) copied, 28.8099 s, 9.3 MB/s


This is on a Class 10 SD card.  I do have a U3 somewhere around here (haven't tested it on the pi yet though), but I think I might just tick a USB on it.