Raspberry Pi
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* If your /var/log/samba/log.smbd fills up with ''printing/print_cups.c:110(cups_connect) Unable to connect to CUPS server localhost'' messages, try http://www.sotechdesign.com.au/samba-log-showing-error-failed-to-retrieve-printer-list/<br/>I also created an empty <code>/etc/printcap</code> to avoid ''Unable to open printcap file /etc/printcap for read'' messages. | * If your /var/log/samba/log.smbd fills up with ''printing/print_cups.c:110(cups_connect) Unable to connect to CUPS server localhost'' messages, try http://www.sotechdesign.com.au/samba-log-showing-error-failed-to-retrieve-printer-list/<br/>I also created an empty <code>/etc/printcap</code> to avoid ''Unable to open printcap file /etc/printcap for read'' messages. | ||
− | === | + | ===Trying to educe number of disk writes (SD card)=== |
− | + | I'm using [http://oss.oetiker.ch/rrdtool/ RRD] with a cron job (currently observing pi's temperature and frequency). I hope that my SD card has proper wear-leveling (and currently my 8 GB card is less than half full), so that the frequent writing should not be a problem. But still, I want to reduce the number of writes to the SD card (in order to not bust it's lifetime). | |
− | + | ||
− | + | Here's what I've done: | |
− | + | ||
− | + | * Edit <code>/etc/default/cron</code> and set <code>EXTRA_OPTS="-L 0"</code> to disable logging (don't need these) | |
− | + | * Avoid entries like <code>pam_unix(cron:session): session closed for user pi</code> in <code>/var/log/auth.log</code> | |
− | + | ** Edit <code>/etc/pam.d/cron</code> and comment the line <code>@include common-session-noninteractive</code> ([http://ubuntuforums.org/showthread.php?t=1256801]) | |
− | + | :or | |
− | + | :* Edit <code>/etc/pam.d/common-session-noninteractive</code> as shown here: http://ubuntuforums.org/showthread.php?t=1256801&p=10283830#post10283830 | |
− | + | * I've implemented a persist tmpfs as discussed in http://www.a-netz.de/2013/02/persistent-storage-with-ramdisks/ and http://www.observium.org/wiki/Persistent_RAM_disk_RRD_storage (and, I guess, many other sites) | |
− | + | ** moved all the .rrd files as well as the created images to my persistent-ramdisk location | |
+ | ** moved <code>/var/spool</code> to my persistent-ramdisk location (and sym-linking /var/spool to it) | ||
+ | ** moved <code>/var/log</code> to my persistent-ramdisk location (and sym-linking /var/log to it) | ||
+ | ** edited <code>/etc/insserv</code> to add the persist-ramdisk as a requirement to $local_fs; the original definition can still be accessed as $local_fs_orig: | ||
$local_fs_orig +mountall +mountall-bootclean +mountoverflowtmp +umountfs | $local_fs_orig +mountall +mountall-bootclean +mountoverflowtmp +umountfs | ||
Line 70: | Line 73: | ||
$local_fs $local_fs_orig +persist-ramdisk | $local_fs $local_fs_orig +persist-ramdisk | ||
− | + | :: <code>/etc/init.d/persist-ramdisk</code> depends on $local_fs_orig, and the other init-scripts keep their dependency to $local_fs. This ensures that /var/log and /var/spool are ok when starting & stopping other init scripts. | |
+ | |||
+ | But still, <code>iostat</code> shows quite some data written to the SD card, according to <code>iotop</code> its ''jbd2'', the journaling part of ext4. | ||
+ | I need to do more digging... | ||
===Useful stuff and Q&A=== | ===Useful stuff and Q&A=== |
Revision as of 00:21, 6 January 2014
Contents |
Cockbook
My collection of hints, tips and tricks (supporting my memory and maybe also helping others).
External USB drives
- Automount USB-Drives in Raspbian
- One may use USBmount and autofs
- I prefer udevil, see below
- Install ntfs-3g if you need write access to ntfs file systems
- How to increase performance?
- Mount with option 'noatime' or 'relatime'
- Mount without option sync (e.g. keep default async)
- If using ntfs-3g (fuse) file system, try mounting with option 'big_writes', see for example http://obihoernchen.net/wordpress/tag/big_writes/
udevil
- exmaple for manual mounting:
udevil mount /dev/sda1
- auto-mounting via udev-rule, see for example http://lsdlinux.org/wiki/doku.php?id=auto_mounting#using_udev_rule (I just copied the 95-udevil-mount.rules file from an OpenElec installation (http://www.raspberrypi.org/downloads) )
- my build-steps (maybe there's a simpler way, but this worked...):
- download 0.4.3/udevil_0.4.3-1_all.deb from https://github.com/IgnorantGuru/udevil/tree/pkg, e.g. using wget
- extract deb-package via
ar vx udevil_0.4.3-1_all.deb
- extract data archive
tar xzvf data.tar.gz
- change to tar usr/share/devil/src
- untar
tar xvfJ udevil-current.tar.xz
-
cd udevil-0.4.3
-
mv distros/debian
- execute
dpkg-buildpackage
- If all required packages are installed, this results in udevil_0.4.3-1_armhf.deb. If the build fails due to missing packages, install the missing packages, and re-do the dpkg-buildpackage step
- Install via
sudo dpkg -i udevil_0.4.3-1_armhf.deb
Samba server / NAS
- How to install?
- Slow disc performance?
- see 'Slow USB drives' above
- use Raspbian, etc without GUI to get as much CPU power for file-transfer as possible (OpenELEC or RaspBMC constantly use about 10-20% CPU load when idle, use top to check!)
- Configuration and tuning
- If your /var/log/samba/log.smbd fills up with printing/print_cups.c:110(cups_connect) Unable to connect to CUPS server localhost messages, try http://www.sotechdesign.com.au/samba-log-showing-error-failed-to-retrieve-printer-list/
I also created an empty/etc/printcap
to avoid Unable to open printcap file /etc/printcap for read messages.
Trying to educe number of disk writes (SD card)
I'm using RRD with a cron job (currently observing pi's temperature and frequency). I hope that my SD card has proper wear-leveling (and currently my 8 GB card is less than half full), so that the frequent writing should not be a problem. But still, I want to reduce the number of writes to the SD card (in order to not bust it's lifetime).
Here's what I've done:
- Edit
/etc/default/cron
and setEXTRA_OPTS="-L 0"
to disable logging (don't need these) - Avoid entries like
pam_unix(cron:session): session closed for user pi
in/var/log/auth.log
- Edit
/etc/pam.d/cron
and comment the line@include common-session-noninteractive
([1])
- Edit
- or
- Edit
/etc/pam.d/common-session-noninteractive
as shown here: http://ubuntuforums.org/showthread.php?t=1256801&p=10283830#post10283830
- Edit
- I've implemented a persist tmpfs as discussed in http://www.a-netz.de/2013/02/persistent-storage-with-ramdisks/ and http://www.observium.org/wiki/Persistent_RAM_disk_RRD_storage (and, I guess, many other sites)
- moved all the .rrd files as well as the created images to my persistent-ramdisk location
- moved
/var/spool
to my persistent-ramdisk location (and sym-linking /var/spool to it) - moved
/var/log
to my persistent-ramdisk location (and sym-linking /var/log to it) - edited
/etc/insserv
to add the persist-ramdisk as a requirement to $local_fs; the original definition can still be accessed as $local_fs_orig:
$local_fs_orig +mountall +mountall-bootclean +mountoverflowtmp +umountfs # we need the sym-link data in /var/log and /var/spool to be available $local_fs $local_fs_orig +persist-ramdisk
-
/etc/init.d/persist-ramdisk
depends on $local_fs_orig, and the other init-scripts keep their dependency to $local_fs. This ensures that /var/log and /var/spool are ok when starting & stopping other init scripts.
-
But still, iostat
shows quite some data written to the SD card, according to iotop
its jbd2, the journaling part of ext4.
I need to do more digging...
Useful stuff and Q&A
- Q: Why does my Pi restart when hotplugging a USB drive?
- Q: Does Raspberry support WOL?
- A: No: the Ethernet chip is connected via USB (http://www.raspberrypi.org/forum/viewtopic.php?f=53&t=39714)
- Q: The new password is to short, or too simple
- A: Try adjusting the PAM settings in
/etc/pam.d/common-password
:- remove the 'obscure' setting for pam_unix.so, and add your desired minimum length (e.g. minlen=2)
password [success=1 default=ignore] pam_unix.so sha512 minlen=2
- !! This is not recommended if your box is connected to the internet or if it contains private data noone should know!!
- But it's nice for testing (if you cannot or do not want to use auto-login.)
- !! This is not recommended if your box is connected to the internet or if it contains private data noone should know!!
- Q: How to configure static IP?
- A: In /etc/network/interfaces:
iface eth0 inet static address 192.168.0.31 netmask 255.255.255.0 gateway 192.168.0.1
- Q: How to read core temperature, etc?
- A: vcgencmd:
vcgencmd measure_temp vcgencmd measure_clock arm
- External USB HDD spin down
- hdparm does not work with my WD Elements (SG_IO: bad host status: 0x7)
- hd-idle works:
hd-idle -a sda -i 600
- for details, see for example http://blog.is-a-geek.org/festplatten-in-den-standby-modus-versetzen-unter-ubuntu-desktopserver-mit-hd-idle (German)
- Q: How to avoid update of a certain package?
- A: Put package on hold ([2] (German)):
echo <paketname> "hold" | dpkg --set-selections
- wikipedia:Raspcontrol with nginx
- Q: How many bytes are written to my (SD) disc?
- A: Use
iostat
http://www.mybinarylife.net/2012/08/linux-iostat-command.html - A: http://guichaz.free.fr/iotop/
- A: Raw data of the kernel can be found in files
/proc/diskstats
and/sys/block/DEVNAME/stat
https://www.kernel.org/doc/Documentation/iostats.txt
Things I want to (or might) try sometime
- Explore overclocking limits of my RaspBerry - currently I'm using medium set via
raspi-config
- NAS/Samba
- try adjusting 'socket options' in (/etc/samba/smb.conf) to increase NAS performance: some websites recommend to disable the 'socket options', some recommend to set:
socket options = TCP_NODELAY IPTOS_LOWDELAY SO_RCVBUF=65536 SO_SNDBUF=65536
- adjust memory split - smaller GPU memory for server
- ext4 vs ntfs for storage drive
- nfs [3] vs samba
- Temperature Sensor DS1820
- http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/temperature/
- https://www.raspiprojekt.de/anleitungen/schaltungen/9-1wire-mit-temperatursensor-ds18b20.html?showall=&start=1 (German)
- http://kopfkino.irosaurus.com/tutorial-ds18s20-temperatur-sensor-an-einem-raspberry-pi/ (German)
- http://raspberrywebserver.com/cgiscripting/rpi-temperature-logger/
- Adjust swap file (size, location -> (ext4) HDD - too slow?): http://manpages.ubuntu.com/manpages/hardy/man8/dphys-swapfile.8.html
- bfq IO scheduler BFQ to increase throughput
Some links
Project sites
Blogs, forums, etc
- http://www.raspberrypi.org/phpBB3/
- Stm Labs Forum / Raspbmc
- Wel!s Blog (German)
- Raspberry Pi Blog of Jan Karres (German)
Misc
Manuals