Can we change the destination directory for the 1 week local history db ?
If ignition Edge is installed on the main memory of the embedded device, I would like to store local history into another storage device like a SD card or an USB external key or HDD.
Just mount that second filesystem at the local history db folder location . . .
Oh, wait. You must be using Windows. /-:
No, raspbian but newbie…
Welcome to the dark side. 
Flexibility in filesystems and storage devices is one of the subjects that’ll turn you into a true Linux/Unix fan-boy.
1 Like
As @pturmel said, you can mount a filesystem to any directory. So unlike Windows (where a file system generally gets a drive letter), the mount command defines where files in your filesystem appear in your directory structure.
http://man7.org/linux/man-pages/man8/mount.8.html
Typically, external filesystems like CD’s or flash drives get mounted under /media or /mnt, but you’re free to choose your own path. If you want to mount it at boot time, that’s normally configured in your bootloader settings.
This does mean that your entire external filesystem will arrive under that directory. If that’s not what you want, perhaps you can take a look at symbolic links (a.k.a. soft links).
http://man7.org/linux/man-pages/man1/ln.1.html
Soft links work like pointers in your filesystem, so you can create a link in one directory and let it point to another directory. That way, when history is written to a path that contains a soft link, it can arrive anywhere, also on an external drive. Note that you must use the “-s” flag to make it a symbolic link, hard links can be annoying with removable storage.
Personally, I like soft links more than odd mount points for external storage. I like to take a quick look at /mnt or /media to see what’s mounted, and the soft links are also more versatile as they allow subdirectories to be used.
2 Likes
If you have only the Ignition Edge MQTT (Transmitter) module (not Edge Panel or Edge Enterprise) and you’re using the default in-memory store, could you chose an SD card for the location of the in-memory store (Ubuntu). If so, where would one change this?
Also, do you have to enable history for the tags to be included in the 1 week store, even though the Edge MQTT module has no history (database) capability, or do the tags just need to be assigned to a transmitter?
The reason this is slightly confusing is because there is a default History Provider called “Edge Historian” available in Edge MQTT (even when Panel and Enterprise are Absent)