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Hi,

Is there a preferred method to go about using a USB flashdrive to store the feed data and/or log files generated by emonCMS on my shiny, new emonPI?

After doing some searching on this forum and coming up short, I installed MC and went about exploring the filesystem on the emonPi. Having done this, my intuition was that this might be accomplished by moving the /home/pi/data directory to the USB drive, adding a symlink in its place and adding the drive to /etc/fstab.

With this in mind, I viewed /etc/fstab and found this:

mpfs           /tmp            tmpfs   nodev,nosuid,size=30M,mode=1777       0    0
tmpfs           /var/log        tmpfs   nodev,nosuid,size=30M,mode=1777       0    0
proc            /proc           proc    defaults                              0    0
/dev/mmcblk0p1  /boot           vfat    defaults                              0    2
/dev/mmcblk0p2  /               ext4    defaults,ro,noatime,errors=remount-ro 0    1
/dev/mmcblk0p3  /home/pi/data   ext2    defaults,rw,noatime                   0    2

This confirmed my suspicions and suggests that I should be able to format a USB stick to ext2 and change that last line to something like:

"/dev/sda  /home/pi/data   ext2    defaults,rw,noatime                   0    2";

but this has now lead to some important questions:

• How big is this data partition?
• How much data is stored here?
• What files are put here?
• How big can the files get?
• How long are they retained?
• Is there any rotation/deletion for logs/feeds when they start getting too large?
• What difference will changing their location make to any retention policies?
• Are there any plans to manage/automate the moving of this data directory, via the emonCMS interface?

I will continue to look into this myself, but if anyone can help shine some light on the subject, I'd very much appreciate their reply.

Thanks,

Rich.