Archive for the ‘*nix’ Category
Posted by jpluimers on 2017/09/12
At the time of discovering Welcome to workaround.org via More ISP Mail saveback – Joe C. Hecht – Google+:
The famous ISP-style mail server tutorials live here. Learn how to set up your own fully-functional mail server using Postfix, Dovecot IMAP/POP3 and MySQL backend on a Debian server just like your favorite mail or website hosting provider.
I have been maintaining the ISPmail tutorial since Debian Woody. However those older Debian versions are no longer supported. If you still like to read the old versions I have provided PDF versions of the tutorials for Squeeze, Lenny, Etch, Sarge andWoody.
My daily work leads to various discoveries and insights. Some were petty but others really brightened my day.
I am a system administrator and programmer. In my nerdy spare time I work on web applications, Python and Ruby programs, write articles or explore new software technologies. On workaround.org you can find news, solutions and hints on my findings and get help. Of course your feedback is welcome.
These are some projects I am currently working on:
- IRC is a great medium for getting instant help (at least on the freenode IRC network). I have collected some tips about Getting help on IRC to help you get help instead of getting barbecued.
- knoba’s factoids
I run a bot called knoba (short for knowledge base) on the freenode IRC network. Two channels I visit frequently are #postfix and #squid. So I have fed the bot with lots of factoids that you can query using !foobar in the channel. These are the factoids understood in #squid and #postfix. Please don’t play with the bot publicly. Send it a “/msg knoba help" and learn how it works.
My daily work leads to various discoveries and insights. Some were petty but others really brightened my day.
Squid is a powerful open-source web proxy. I was responsible for a large Squid installation at a former employer. Maybe the following articles help you save time in your daily work.
Padrino is an lean Ruby web framework. It is an interesting alternative to the heavier Ruby-on-Rails. I spent quite some time with it and created a couple of articles about it:
Zabbix is a mighty open-source monitoring software. If you need a serious system for your organisation and manage to condone its creepy web interface it is hands down the the most superior software I have ever seen. And I have been dealing with monitoring software since Nagios was called Netsaint.
These articles should help you in your daily work maintaining a monitoring system:
–jeroen
Posted in *nix, BIOS, Boot, Development, Linux, Open Source, Power User, Software Development | Leave a Comment »
Posted by jpluimers on 2017/09/07
Interesting reads:
Need to research how I can fit noatime ino.
–jeroen
Posted in *nix, *nix-tools, btrfs, File-Systems, Power User | Leave a Comment »
Posted by jpluimers on 2017/08/28
This is so cool, but will take some time for lot’s of tooling to become compatible:
Starting with v197 systemd/udev will automatically assign predictable, stable network interface names for all local Ethernet, WLAN and WWAN interfaces. This is a departure from the traditional interface naming scheme (“eth0”, “eth1”, “wlan0”, …), but should fix real problems.
–jeroen
Posted in *nix, *nix-tools, Linux, Power User, systemd | Leave a Comment »
Posted by jpluimers on 2017/08/21
I didn’t notice this bind change for a while, but some time ago after doing an rcnamed restart it would split out this error message:
the working directory is not writable
It seems harmless as BIND still starts:
Starting name server BIND ..done
Anyway, some links that helped me solve it:
The last entry provides the solution:
rcnamed stop
chown named:named /var/lib/named/ -R
rcnamed start
rcnamed status
The latter didn’t show any error message.
–jeroen
Posted in *nix, bind-named, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »
Posted by jpluimers on 2017/08/17
Reproduction of A start job is running for dev-disk-by... – Google Photos / Oops. Let’s see if I can reproduce it, as I think this is related: https://…
Reproducible steps below.
Related:
Tried tips from last link: fails as well
These are the modifications of the steps further on based on the last link above.
- After first boot, verify the WiFi drivers are there:
# rpm -qa | grep bcm43xx
bcm43xx-firmware-20170410-2.1.noarch
- After editing
/etc/dracut.conf.d/raspberrypi_modules.conf, perform sudo mkinitrd without any -f
- After reboot, same error
Error result
At boot time:
A start job is running for dev-disk-by\…
After waiting:
Reproducible steps
- download (or a more recent one) from http://download.opensuse.org/repositories/devel:/ARM:/Factory:/Contrib:/RaspberryPi3/images/ :
- Install them on a MicroSD card
- Put in Raspberry Pi 3 and boot
- Get the IP address of the machine, then SSH into it (
ssh root@ip-address, password linux)
- Follow the steps from [WayBack] openSUSE on Raspberry Pi 3: From Zero to Functional System in a Few Easy Steps – SUSE Blog | SUSE Communities to get WiFi working:
- Edit
/etc/dracut.conf.d/raspberrypi_modules.conf and remove the sdhci-iproc from the first and # on the last line:From :
add_drivers+=" sdhci-iproc bcm2835-sdhost bcm2835_dma mmc_block dwc2 "
# Workaround for Wifi
#omit_drivers+=" sdhci-iproc"
To :
add_drivers+=" bcm2835-sdhost bcm2835_dma mmc_block dwc2 "
# Workaround for Wifi
omit_drivers+=" sdhci-iproc"
- Run these commands:
mkinitrd -f
reboot
- Check in
Yast if wlan0 exists in System -> Network Settings, then assign an SSIS plus credentials to it
- Verify the list contains
BCM43430 WLAN card
- Select it
- Click the
Edit button
- Put the check mark next to
Dynamic Address then select DHCP and the kind of DHCP (in my caseboth version 4 and 6)
- Click the
Next button
- Keep
Operating Mode as Managed
- Click the
Scan Network button
- Select
Network Name (ESSID) from the list
- Select
Authentication Mode from the list
- Put the check mark for
Key Input Type as Passphrase
- Enter the
Encryption Key
- Click the
Next button
- Click the
OK button
- Quit
Yast
- Wait a few moments, then very with
ip a that wlan0 got an IP address
- Update the system:
zypper refresh
zypper dist-upgrade
- Reboot
- Wait for the error to occur on the HDMI screen (USB keyboard does not work there, so I cannot copy logs)
Gist log until 7. is below.
IRC chat transcript opensuse-factory
[10:40am] <wiert> TL;DR: Tumbleweed on Rpi3; enable WiFi according to site and forum instructions; zypper dist-upgrade; boot failure.
[10:41am] <wiert> without enabling WiFi everything is fine.
[10:41am] <wiert> spare RPi3s get in next week, so I’ll configure this one for my brother without WiFi for now.
[10:43am] <fvogt> Hm, that guide can’t actually work that way (unless something changed significantly)
[10:43am] <wiert> it worked in the sense that it got WiFi working. it failed in the sense that you cannot upgrade any more (:
[10:43am] <fvogt> The omit_drivers line removed the driver for the sd card controller, so it’s no surprise that it doesn’t boot anymore. It needs a different device tree
[10:44am] <fvogt> I guess you upgraded the kernel + DT? You must not do that
[10:44am] <wiert> funny as after the mkinitrd, a reboot went fine.
[10:44am] <wiert> it’s only that after a zypper dup it fails.
[10:44am] <mnowak__> DimStar, I wan’t $$ only on Windows, I should not have to re-define $prompt_sign. I guess I need to move the second $prompt_sign to the if-clause below
[10:45am] <fvogt> wiert: Ah, so it ships with a WiFi enabled DT + Kernel with the TW image
[10:45am] <fvogt> If you zypper dup then, it’ll switch to the DT + Kernel from plain TW, breaking everything
[10:46am] <wiert> What’s DT?
[10:46am] <wiert> driver-tree?
[10:46am] <fvogt> Close, device-tree
[10:46am] <wiert> (that gist has all the steps I performed)
[10:46am] <fvogt> It contains the assignment of memory and other HW resources to each other and drivers
[10:47am] <fvogt> That’s most likely the issue
[10:48am] <fvogt> You can recover from that by downloading the right .dtb file and putting it on the sd card manually
[10:48am] <fvogt> Alternatively, the u-boot embedded one should still work, so you can delete the DT on the SD and it should boot again (with some missing peripherals though)
[10:51am] <wiert> I’ve already put a fresh disk image on it and I’m in the midst of configuring it for my brother (he’s mentally retarded and I’m putting it behind his TV so he can view his agenda electronically to see if that gives him more stability in organising his life; I need to be at his place in 2 hours)
[11:27am] <wiert> @fvogt: I will add this part of the IRC chat to that blog post and try to get your suggestions done when the spare RPI3s get in.
–jeroen
Read the rest of this entry »
Posted in *nix, Development, Hardware Development, Linux, openSuSE, Power User, Raspberry Pi, SuSE Linux, Tumbleweed | Leave a Comment »
Posted by jpluimers on 2017/08/07
sslh accepts connections on specified ports, and forwards them further based on tests performed on the first data packet sent by the remote client.
Probes for HTTP, SSL, SSH, OpenVPN, tinc, XMPP are implemented, and any other protocol that can be tested using a regular expression, can be recognised. A typical use case is to allow serving several services on port 443 (e.g. to connect to ssh from inside a corporate firewall, which almost never block port 443) while still serving HTTPS on that port.
Hence sslh acts as a protocol demultiplexer, or a switchboard. Its name comes from its original function to serve SSH and HTTPS on the same port.
sslh supports IPv6, privilege dropping, transparent proxying, and more.
Interesting…
–jeroen
Posted in *nix, https, Linux, OpenSSL, OpenVPN, Power User, Security | Leave a Comment »
Posted by jpluimers on 2017/08/01
Uptime robot (free for 50 monitors every 5 minutes) is cool:
[Archive.is]
[Archive.is]
These are xs4all fiber connections in Amsterdam and Sassenheim. Despite not mentioned on the xs4all status page [WayBack] XS4ALL | Storingen en werkzaamheden, apparently there was some fiber down time in both places.
The HeldenVanNu fiber connection in Amsterdam was doing fine at that time; those downtimes below were planned on my side:
[Archive.is]
–jeroen
Posted in Monitoring, Power User | Leave a Comment »
Posted by jpluimers on 2017/07/31
I could not find many potential anti-virus and -malware tools for OpenSuSE Tumbleweed despite they would be useful not only for non-Linux clients like Windows and Mac OS X.
These I found:
–jeroen
Posted in *nix, Linux, openSuSE, Power User, SuSE Linux, Tumbleweed | Leave a Comment »
Posted by jpluimers on 2017/07/27
Not sure why without the -z compression switch this succeeds:
# rsync -avloz /var/lib/named/master/ /etc/named/master/
sending incremental file list
pluimers.com
Segmentation fault (core dumped)
# rsync -avlo /var/lib/named/master/ /etc/named/master/
sending incremental file list
pluimers.com
pluimers.com.20161231
pluimers.com~
sent 10,495 bytes received 74 bytes 21,138.00 bytes/sec
total size is 132,231 speedup is 12.51
# rsync -avloz /var/lib/named/master/ /etc/named/master/
sending incremental file list
sent 1,547 bytes received 13 bytes 3,120.00 bytes/sec
total size is 132,231 speedup is 84.76
–jeroen
via: [WayBack] rsync(1) – Linux man page
Posted in *nix, *nix-tools, Power User, rsync | Leave a Comment »
The Wiert Corner - irregular stream of stuff 