Josef “Jeff” Sipek

First, a little bit of history…

Many years ago, I tried various phone apps for recording my bike rides. Eventually, I settled on Strava. This worked great for the recording itself, but because my phone was stowed away in my saddle bag, I didn’t get to see my current speed, etc. So, in July 2012, I splurged and got a Garmin Edge 500 cycling computer. I used the 500 until a couple of months ago when I borrowed a 520 with a dying battery from someone who just upgraded and wasn’t using it. (I kept using the 500 as a backup for most of my rides—tucked away in a pocket.)

Last week I concluded that it was time to upgrade. I was going to get the 540 but it just so happened that Garmin had a sale and I could get the 840 for the price of 540. (I suppose I could have just gotten the 540 and saved $100, but I went with DC Rainmaker’s suggestion to get the 840 instead of the 540.)

Backups

For many years now, I’ve been backing up my 500 by mounting it and rsync’ing the contents into a Mercurial repository. The nice thing about this approach is that I could remove files from the Garmin/Activities directory on the device to keep the power-on times more reasonable but still have a copy with everything.

I did this on OpenIndiana, then on Unleashed, and now on FreeBSD. For anyone interested, this is the sequence of steps:

$ cd edge-500-backup
# mount -t msdosfs /dev/da0 /mnt
$ rsync -Pax /mnt/ ./
$ hg add Garmin
$ hg commit -m "Sync device"
# umount /mnt

This approach worked with the 500 and the 520, and it should work with everything except the latest devices—540, 840, and 1050. On those, Garmin switched from USB mass storage to MTP for file transfers.

After playing around a little bit, I came up with the following. It uses a jmtpfs FUSE file system to mount the MTP device, after which I rsync the contents to a Mercurial repo. So, generally the same workflow as before!

$ cd edge-840-backup
# jmtpfs -o allow_other /mnt
$ rsync -Pax \
	--exclude='*.img' \
	--exclude='*.db' \
	--exclude='*.db-journal' \
	/mnt/Internal\ Storage/ edge-840-backup/
$ hg add Garmin
$ hg commit -m "Sync device"
# umount /mnt

I hit a timeout issue when rsync tried to read the big files (*.img with map data, and *.db{,-journal} with various databases, so I just told rsync to ignore them. I haven’t looked at how MTP works or how jmtpfs is implemented, but it has the feel of something trying to read too much data (the whole file?), that taking too long, and the FUSE safety timeouts kicking in. Maybe I’ll look into it some day.

Aside from the timeout when reading large files, this seems to work well on my FreeBSD 14.2 desktop.