Hahah yes, I did expect that comment! I’m sure you will also be expecting my reply
IMHO it’s unnecessary to run a full desktop OS on a headless box.
As for future proofness, Jessie lite is officially released and supported by the Raspbian team and can access any Jessie package from the repositories.
I’m not planning on doing a full image re-build this time, just an interim release pulling in all the latest security updates, fixes and possible adding a couple of new features.
If a user wishes Jessie Lite can be ‘upgraded’ to full Jessie by installing the following:
@glyn.hudson - make sure the pre-release built is clean;
“apt-get clean all” - for example this cleaned up ~700MB of apt cache on my system.
I’m currently looking at the rest of the file system to see what else can be cleaned up
/var/swap exists in the image - despite swap being off, so thats another ~100MB to clean up.
Does the just clean up remove unused tempory package files. Is there no detrimental effects? Why is clean no run automatically as part of the linux package instal?
Packages are NOT removed, only cached information (and therefore cached copies of installed applications).
Since the installed base isn’t likely to change - I would encourage you to “apt-get clean all” to remove the crap.
IF you want to remove installed but un-used applications, that should be “apt-get autoremove --purge”
However your system is already clean;
pi@emonpi(rw):~$ sudo apt-get autoremove --purge
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Another nice addition - you might notice my prompt that tells me when the filesystem is “ro” or “rw” - add the following code to the end of /etc/bash.bashrc
set_bash_prompt(){
fs_mode=$(mount | sed -n -e "s/^\/dev\/mmcblk0p2 on \/ .*(\(r[w|o]\).*/\1/p")
if [ $(id -u) -eq 0 ];
then
PS1='\[\033[01;31m\]\u@\h${fs_mode:+($fs_mode)}\[\033[00m\]:\[\033[01;34m\]\W\[\033[00m\]\$ '
else
PS1='\[\033[01;32m\]\u@\h${fs_mode:+($fs_mode)}\[\033[00m\]:\[\033[01;34m\]\W\[\033[00m\]\$ '
fi
}
# setup fancy prompt
PROMPT_COMMAND=set_bash_prompt
This also turns the whole prompt RED if you are root
Hope those help.
Wow, that’s really useful! I’ve lost count of the number of times I edit a file with nano but then unable to save changes since I forgot to toggle RW. Nice work, I’ll make sure that get’s into the next release
I guess it might also be possible to add it to existing systems via emonpi update…
As for the filesystem sizing, you could (now that we have a proven way to clean up) actually reduce your root volume to 3G leaving another 400MB for logging data.
My modifications include creating specifically sized partitions (rather than filling the target SD card) and writing zeros (from /dev/zero) in all of the free space, so that when I then pull the image back, truncate it and compress it - I get a SERIOUS compression advantage (because compressed zeros take up zero space…)
Nice, thanks for the tips. That script looks useful. I have been using dd after removing the SD card from the Pi and Gparted if partitions need editing.
So I use that to clone the working system onto a new SD card, mine is modified to not copy things like .bash_history etc, so I have some added excludes (you can find these easily enough)
mkdir -p $CLONE/var/log
#
# Clean the disk (full the partition with zeros to help with later compression)
#
echo ""
echo "*** Writing zero's to the remaining disk space, this will take a few mins..."
echo ""
dd if=/dev/zero of=$CLONE/large.file bs=1M count=2048
sleep 5
rm -rf $CLONE/large.file
Once the image write has completed, I then use DD to pull the whole image back, and then use truncate to rip the image down to only the used space on the SD Card;
Read this: How to trim disk images to partition size | Linux M0nk3ys
Now you have your collapsed SD Card image, you can zip that as normal and it should get significantly reduced in size.
I should have added this part too, this is where i set the size of the target root filesystem;
# Borrowed from do_expand_rootfs in raspi-config
expand_rootfs()
{
# Get the starting offset of the root partition
# (with Jessie's parted, now need to strip trailing 's' from PART_START)
PART_START=$(parted /dev/mmcblk0 -ms unit s p \
| grep "^2" | cut -f 2 -d: | cut -f 1 -d s)
[ "$PART_START" ] || return 1
# Return value will likely be error for fdisk as it fails to reload the
# partition table because the root fs is mounted
fdisk /dev/$DST_DISK > /dev/null <<EOF
p
d
2
n
p
2
$PART_START
+1780M
p
w
q
EOF
}
You will need to modify this to set the root partition size AND to create the /home/pi/data partition too
Adding this to the /etc/bash.bashrc will remove the need for the files altogether
# Aliases to control re-mounting
alias rpi-ro='sudo mount -o remount,ro / ; sudo mount -o remount,ro /boot'
alias rpi-rw='sudo mount -o remount,rw / ; sudo mount -o remount,rw /boot'
I should point out that if you have other scripts that rely on running ‘rpi-ro’ and or ‘rpi-rw’ - using aliases is probably not a good idea…
Some time ago I was working on a “rpi” script that offered many options from creating a data partition, adding a hdd, switching between a RO OS and standard OS, enabling MQTT, enabling the LAMP etc etc, This was offered to T&G way before the emonPi or the emonPi image was here. I have not pursued this due to the current trend not to ssh in favor of the emoncms config pages.
Here’s my forwarding only emonbase via ssh,
Using username "pi".
Authenticating with public key "pb66" from agent
Linux energyPi 3.18.11+ #781 PREEMPT Tue Apr 21 18:02:18 BST 2015 armv6l
___ ___ __ __ _ _
/ _ \ _ __ ___ _ _ | __|_ _ ___ _ _ __ _ _ _| \/ |___ _ _ (_) |_ ___ _ _
| (_) | '_ \/ -_) ' \| _|| ' \/ -_) '_/ _` | || | |\/| / _ \ ' \| | _/ _ \ '_|
\___/| .__/\___|_||_|___|_||_\___|_| \__, |\_, |_| |_\___/_||_|_|\__\___/_|
|_| |___/ |__/ .org
(type 'emon' for details)
pi@energyPi ~ $ rpi
The 'rpi' command options
General utilities
-c | --config Opens an extended 'raspi-config' user menu
-h | --help Display this help for 'rpi' command options
-u | --update Updates the Raspbian OS & debian packages
-l | --lock Lock (read-only enabled filesystem)
-o | --open Open (read-only enabled filesystem)
-s | --status Report status information
File system utilities
-er | --enable-ro Configures filesystem as read-only
-dr | --disable-ro Reverse changes to read-only filesystem
-ro | --read-only Lock (read-only enabled filesystem)
-rw | --read-write Open (read-only enabled filesystem)
-ad | --add-datapart Add a data partition
-mr | --move-rootfs Configures OS & rootfs on USB drive
-em | --enable-mqtt Enable Mosquitto MQTT v3.1.1 server
pi@energyPi ~ $ emonhub
The 'emonhub' command options
emonHub utilities
-c | --config Configure emonHub by editing emonhub.conf
-t | --crontab Opens emonHub's crontab time scheduler
-h | --help Display help for 'emonhub' command options
-r | --restart Restart the emonhub service
-s | --start Start the emonhub service
-u | --update Update emonHub via the git repository
-v | --version Display the emonHub version installed
-x | --exit Exit emonHub by stopping the emonhub service
-d | --disable Disable emonHub from starting automatically
-e | --enable Enable emonHub to always start automatically
emonHub logging
-dl | --display-log Display last 10 & on-going log messages
-ol | --open-logfile Open logfile in nano text editor
-rl | --reset-logfile Reset the current logfile (deletes log!)
-vl | --view-logfile View the entire logfile
pi@energyPi ~ $ emoncms
Note emonCMS has not been fully installed & configured yet
The following commands will be available once emonCMS is installed
The 'emoncms' command options
emonCMS utilities
-c | --config Opens emoncms.conf for configuration
-h | --help Display this 'emoncms' command options help
-u | --update Updates emonCMS via the git repository
emonCMS setup
-da | --disable-all Disables the server, database & emonCMS
-el | --enable-lite Enables server, database & lite emonCMS
-ef | --enable-full Enables server, database & full emonCMS
To install emonCMS use 'emoncms --install' for installer options
pi@energyPi ~ $
Bill suggested the changes to bash.rc for (RW) and (RO) way back, at the time I actually got the prompt to change colour, red for RO and green for RW but I’ve since lost that feature some where along the line.
EDIT - Oh! I forget I made the “emon” option that listed them all, just spotted above.
pi@energyPi ~ $ emon
The 'OpenEnergyMonitor' Open-source Hardware & Software project
navigation via the 'rpi', 'emonhub' & 'emoncms' commands
The 'rpi' command options
General utilities
-c | --config Opens an extended 'raspi-config' user menu
-h | --help Display this help for 'rpi' command options
-u | --update Updates the Raspbian OS & debian packages
-l | --lock Lock (read-only enabled filesystem)
-o | --open Open (read-only enabled filesystem)
-s | --status Report status information
File system utilities
-er | --enable-ro Configures filesystem as read-only
-dr | --disable-ro Reverse changes to read-only filesystem
-ro | --read-only Lock (read-only enabled filesystem)
-rw | --read-write Open (read-only enabled filesystem)
-ad | --add-datapart Add a data partition
-mr | --move-rootfs Configures OS & rootfs on USB drive
-em | --enable-mqtt Enable Mosquitto MQTT v3.1.1 server
The 'emonhub' command options
emonHub utilities
-c | --config Configure emonHub by editing emonhub.conf
-t | --crontab Opens emonHub's crontab time scheduler
-h | --help Display help for 'emonhub' command options
-r | --restart Restart the emonhub service
-s | --start Start the emonhub service
-u | --update Update emonHub via the git repository
-v | --version Display the emonHub version installed
-x | --exit Exit emonHub by stopping the emonhub service
-d | --disable Disable emonHub from starting automatically
-e | --enable Enable emonHub to always start automatically
emonHub logging
-dl | --display-log Display last 10 & on-going log messages
-ol | --open-logfile Open logfile in nano text editor
-rl | --reset-logfile Reset the current logfile (deletes log!)
-vl | --view-logfile View the entire logfile
Note emonCMS has not been fully installed & configured yet
The following commands will be available once emonCMS is installed
The 'emoncms' command options
emonCMS utilities
-c | --config Opens emoncms.conf for configuration
-h | --help Display this 'emoncms' command options help
-u | --update Updates emonCMS via the git repository
emonCMS setup
-da | --disable-all Disables the server, database & emonCMS
-el | --enable-lite Enables server, database & lite emonCMS
-ef | --enable-full Enables server, database & full emonCMS
To install emonCMS use 'emoncms --install' for installer options
pi@energyPi ~ $
Also the use of apt-get clean was discussed at length way back when Glyn was struggling to get the image on a 4gb card before going down the slim OS route.
Neither of these points take anything away from Andy, they are both good points to be raised again, it just shows how much unused and at the time perhaps unappreciated information is hidden away in the depths of these forums.
