September 2016 - luv-main

making vim work properly - or other editor
by Russell Coker 20 Oct '16

20 Oct '16

I run Debian/Unstable on my laptop because I'm a DD and it helps to test all the new software. The new version of VIM has just been added, and I don't like it. By default it uses it's own copy/paste mechanism and doesn't seem to support the system clipboard. What I want is to have VIM not really know about the system clipboard and just use a middle-button click to paste with my Xterm (Konsole in this case) and have VIM just take the text. Is it possible to do this with the new version of VIM? What are other good programmers editors? I want something that will preserve white-space so it doesn't generate ridiculous diffs (no converting tabs to spaces or spaces to tabs). -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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Internode + Nodephone + Asterisk (+FreePBX?)
by Michael Schams 18 Oct '16

18 Oct '16

Hi there, We are planning to switch from a standard phone line to Nodephone VoIP from Internode. I am very keen to test if Asterisk (maybe in combination with FreePBX) is an option for a small team (one trunk, 6 to 8 endpoints, all with various SIP clients). I successfully set up Asterisk 13 and pjsip and FreePBX 13 on a pretty standard Debian 8 box. I suspect the challenges start when it comes to the VoIP SIP details for the trunk. I came across a few forum posts and discussions about the Internode settings, but I wonder if anyone from the LUV community runs such a setup or has some experience with Asterisk and Internode (especially their Nodephone product)? As I pointed out above, we don't have the line yet, so it's more curiosity than a specific problem I want to solve (yet) :-) Any feedback is welcome. Cheers Michael

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How to make systemd more reliable
by Tim Connors 11 Oct '16

11 Oct '16

Stop using it! And that part is easy, just run NOTIFY_SOCKET=/run/systemd/notify systemd-notify "" in a while 1 loop as an ordinary user. https://www.agwa.name/blog/post/how_to_crash_systemd_in_one_tweet (sorry for the flamebait first line - I know this list is full of systemd fanbois) -- Tim Connors

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Orbital simulation
by Russell Coker 26 Sep '16

26 Sep '16

Is there a good free orbital simulator for Linux? I don't want a game like KSP but a simulation of orbits without much need for fancy graphics. I am wondering what the orbit of a ring would be like (EG a Dyson ring) and whether it's plausible to make such a ring or whether a set of disconnected sattelites in the same orbit is required. -- Sent from my Nexus 6P with K-9 Mail.

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another outage
by Russell Coker 24 Sep '16

24 Sep '16

The virtual machine running the LUV server was killed by the kernel OOM 4 hours ago. I didn't immediately notice because the VM running my Jabber server (which notifies me of system problems) was also killed). When we had the last problem I converted the virtual machines from Xen to KVM. With KVM the VMs are regular Linux processes and they share the same memory as regular processes. So if another process allocates too much RAM then it may cause KVM memory allocation to fail. Also if the entire system runs out of RAM the kernel may stupidly decide to kill the KVM instance instead of something else. I think that part of the problem was that BOINC was configured to use up to 90% of system RAM. That was an OK setting for a Xen server where the Dom0 had nothing of note running other than BOINC and the virtual machines had RAM reserved. When running KVM this wasn't a suitable setting. I've configured BOINC to only use 40% of RAM and increased swap size. This shouldn't happen again. Also I'm going to move the Jabber server to the Dom0 so that if the DomUs die then I can still get alerts. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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ZFS error logging
by Russell Coker 23 Sep '16

23 Sep '16

Below is part of the output of "zpool status". It seems that sdr is defective, it has a steadily increasing number of checksum errors. Would the "resilvered 763M" part be about the 121 checksum errors? If so does that mean each checksum error required resilvering on average 6M of data? The kernel message log has NOTHING about this. I'm used to Ext* and BTRFS which give kernel message log entries about filesystem errors. Can ZFS be configured to give similar logging? As an aside I've written a mon module for monitoring for such ZFS errors. I'll release it sometime soon. But I'd be happy to give a version that's quite usable although not ready for full release to anyone who wants it. status: One or more devices has experienced an unrecoverable error. An attempt was made to correct the error. Applications are unaffected. action: Determine if the device needs to be replaced, and clear the errors using 'zpool clear' or replace the device with 'zpool replace'. see: http://zfsonlinux.org/msg/ZFS-8000-9P scan: resilvered 763M in 0h0m with 0 errors on Thu Aug 18 14:48:53 2016 config: NAME STATE READ WRITE CKSUM server ONLINE 0 0 0 raidz1-0 ONLINE 0 0 0 sdj ONLINE 0 0 0 sdk ONLINE 0 0 0 sdl ONLINE 0 0 0 sdm ONLINE 0 0 0 sdn ONLINE 0 0 0 sdo ONLINE 0 0 0 sdp ONLINE 0 0 0 sdq ONLINE 0 0 0 sdr ONLINE 0 0 121 -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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Postfix + Dovecot (+MySQL)
by Piers Rowan 21 Sep '16

21 Sep '16

Hi there, I set up a VM a couple of weeks back as a mail server. I can send email via web mail and I can get email in but I can't get it to relay. cat /etc/postfix/main.cf | grep restrictions # overcome chroot restrictions. The alternative, having a copy of # through Postfix. See the smtpd_recipient_restrictions parameter # relay mail to. See the smtpd_recipient_restrictions description in smtpd_relay_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination mua_client_restrictions = permit_sasl_authenticated,reject mua_helo_restrictions = permit_sasl_authenticated,reject mua_sender_restrictions = permit_sasl_authenticated,reject smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,check_policy_service unix:/var/spool/postfix/postgrey/socket smtpd_recipient_restrictions = reject_invalid_hostname, reject_unknown_recipient_domain, reject_unauth_pipelining, permit_mynetworks, reject_unauth_destination, permit_sasl_authenticated, check_policy_service unix:/var/spool/postfix/postgrey/socket, reject_rbl_client zen.spamhaus.org, reject_rbl_client bl.spamcop.net, reject_rbl_client dnsbl.sorbs.net, reject_rbl_client cbl.abuseat.org, reject_rbl_client b.barracudacentral.org, reject_rbl_client dnsbl-1.uceprotect.net,permit cat /etc/postfix/master.cf | grep restrictions -o smtpd_client_restrictions=$mua_client_restrictions -o smtpd_helo_restrictions=$mua_helo_restrictions -o smtpd_sender_restrictions=$mua_sender_restrictions -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject # -o smtpd_client_restrictions=$mua_client_restrictions # -o smtpd_helo_restrictions=$mua_helo_restrictions # -o smtpd_sender_restrictions=$mua_sender_restrictions # -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject -o smtpd_client_restrictions= -o smtpd_helo_restrictions= -o smtpd_sender_restrictions= -o smtpd_recipient_restrictions=permit_mynetworks,permit_sasl_authenticated,reject Any ideas? I'm not familiar with Postfix. Thanks Piers

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TCP rate/congestion control
by Toby Corkindale 19 Sep '16

19 Sep '16

I noticed that Windows 10 now uses CTCP as the default TCP congestion/rate control algorithm, but Linux still defaults to the old Cubic algorithm. CTCP doesn't appear to be available on Ubuntu LTS at the moment, but there's a whole host of others to choose from. Has anyone here worked out which is the best one to use on typical consumer internet links in Australia? (ie. ADSL with 4-12 mbps and only minor packet loss) Available options on Ubuntu Xenial: - bic - cubic - cdg - dctcp - diag - highspeed - htcp - hybla - illinois - lp - probe - reno - scalable - vegas - veno - westwood - yeah

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Can anyone make suggestions for training / learning resources wrt databases.
by h 18 Sep '16

18 Sep '16

Hi, I am a linux hobbyist. I have been using postgis for a while, at a hobby level, to provide data for web pages and for QGIS. I am reasonably confident writing sql statements, and being able to find the information I need to get the data I am after. There are two areas I have been unable to find information on: * Writing sql / script files * Structuring tables either within a database, or on a server The particular problems I have are: * I regularly update my tables from multiple csv files, all residing in the same folder. Currently I have a script with a hardwired path for each csv file. I would like to have a single 'variable' I could change to define the path to all the csvs. * I have a database which I have decided should contain three types of table - core definitions / lookups, - raw data and - derived data for specific tasks. I would like to create separate areas in the database / (server?) for each table type, or learn of other options for how the tables could be structured. I am NOT looking for specific answers to these problems, but rather some teaching / groundwork information about relational databases / sql / postgis concepts. I have seen training videos / websites covering writing queries and on database security, but cannot find anything on script files, or database structure. I suspect wrong terminology and poor google skills are to blame. Can anyone suggest web sites etc that provide information on either / both of these two topics? With thanks Hugh

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Re: OT: trains & demand tariffs [Was: outage]
by Anthony 17 Sep '16

17 Sep '16

On Tue, Sep 13, 2016 at 12:23 PM, Russell Coker via luv-main < luv-main(a)luv.asn.au> wrote: > Interesting. I've been wondering how difficult it would be to use some IP > enabled switches to control home energy use. If you had a meter on the > main > power that reports the power use to a Linux system then you could have it > turn > off non-essential devices and make your PCs stop running BOINC if power > use is > too high. > Hrrmm.. Well, the smart meters in Victoria are supposed to use the "Zigbee Power" version 1 protocol. I know that for the distribution company within the area I reside (Jemena), I need only log into their portal (which also allows me to browse my power usage data online up to four hours ago at an hourly resolution or so, and to download a CSV that has data going back to when the meter was installed), specify the MAC address and installer code of the Zigbee device I wish to pair with my meter, and then that device can receive information from my smart meter. This is primarily for "in home displays", but presumably there's gotta be a device that's linux friendly out there that talks Zigbee Power v1?

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