This resembles the 32 GB Micro SD card checkout, with the exception that, for some unknown reason, the available space doesn’t match up with the actual space occupied by the file. It also turns out that rsync deletes the incomplete file, rather than leaving a stub, which makes perfect sense, but was still a bit disappointing after two hours.
I had two identical Sandisk Cruzer Fit Flash Drives, one of which appears here:
Those squares are an inch on a side, so it’s a bit larger than the Micro SD card. Adding a lanyard loop on the plastic cap or a string between cap and drive seems like a great idea, because that little thing is certain to get lost.
The snippets here represent a compendium of Things Done that happened over the course of two days; I didn’t save all the logs. The process started with the same 32 GB file of entropy I used for the Micro SD card:
df -B1 /mnt/part2 Filesystem 1B-blocks Used Available Use% Mounted on /dev/sdc1 31512350720 180424704 31331926016 1% /mnt/part2 ----------------------- time rsync --progress /mnt/part/Testdata/Testdata.bin /mnt/part2 Testdata.bin 31298191360 99% 14.18kB/s 0:39:38 rsync: writefd_unbuffered failed to write 4 bytes to socket [sender]: Broken pipe (32) rsync: write failed on "/mnt/part2/Testdata.bin": No space left on device (28) rsync error: error in file IO (code 11) at receiver.c(322) [receiver=3.0.9] rsync: connection unexpectedly closed (28 bytes received so far) [sender] rsync error: error in rsync protocol data stream (code 12) at io.c(605) [sender=3.0.9] real 126m20.505s user 3m6.393s sys 2m17.492s ----------------------- time dd bs=8K count=20000000 if=/mnt/part/Testdata/Testdata.bin of=/mnt/part2/Test1.bin dd: writing ‘/mnt/part2/Test1.bin’: No space left on device 3820963+0 records in 3820962+0 records out 31301320704 bytes (31 GB) copied, 7455.97 s, 4.2 MB/s real 124m15.970s user 0m1.607s sys 1m17.546s ----------------------- truncate -s 31301320704 /mnt/part/Testdata/Testdata.bin ----------------------- ll /mnt/part/Testdata/Testdata.bin -rw-r--r-- 1 ed ed 31301320704 Dec 24 18:13 /mnt/part/Testdata/Testdata.bin ----------------------- time diff /mnt/part/Testdata/Testdata.bin /mnt/part3/Test1.bin real 26m37.081s user 0m4.400s sys 0m52.723s
Notice that the write speed runs around 4 MB/s, which is a lot slower than you might expect from a USB 2.0 device; as with a hard drive, the interface doesn’t limit the throughput! The read speed, on the other paw, trots along at about 20 MB/s.
One of these will go to Mary’s folks as an online daily backup device; their PC will soon run a version of the rsnapshot scripts that back up our basement file server. It’s not off-site backup and it’s not proof against catastrophic hardware failure, but it should be good enough.
The Smell of Molten Projects in the Morning 