luv-main April 2017

luv-main@luv.asn.au

14 participants
11 discussions

by Andrew Pam

I'm trying to cut down on the number of computers in my house. Here's the first one I'm offering free to anyone who wants it: Compaq Evo N410c laptop with docking bay and a D-Link DWL-G630 PC-card WiFi adapter 1.2GHz Pentium III-M, 1GB RAM, 63GB HDD, 1024x768 LCD with ATI Radeon Mobility M6 LY chipset Ports: VGA, audio, 2xUSB, IRDA, internal modem, Ethernet, PC-card slot, serial, parallel and composite video out (!) The docking bay has stereo speakers, 2x drive bays with a DVD drive and a 3.5" floppy drive and the following ports: VGA, audio, 2xUSB, Ethernet, PS/2 keyboard and mouse, serial and parallel. I can bring it to the LUV meeting on Tuesday night, or you can pick it up from my office in North Richmond during office hours next week. Cheers, Andrew

5 years, 5 months

reported nasty bash bug -- arithmetic problem, incorrect return code with ((var++)) when var is 0 before operation

by Andrew McGlashan

Configuration Information [Automatically generated, do not change]: Machine: x86_64 OS: linux-gnu Compiler: gcc Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu' -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H -I. -I../. -I.././include -I.././lib -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wall uname output: Linux andrewm-Satellite-P50-A 4.4.0-72-generic #93-Ubuntu SMP Fri Mar 31 14:07:41 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux Machine Type: x86_64-pc-linux-gnu Bash Version: 4.3 Patch Level: 42 Release Status: release Description: The return code from ((i++)) operation is different when i has an initial value of 0. This problem was discovered when running run a bash script with "set -ue" and having "((i++))" as the last command in a loop. Repeat-By: The following script will quit with an error after the first iteration due to the return code errantly being 1. #!/bin/bash set -eu i=0 for a in a b c do echo "${a}" ((i++)) done NB: If i starts as 1, the script works as expected. Also, using ((i+=1)) works fine, but I prefer the ((i++)) format. Proof outside a loop: $ c=0;((c++));echo $? 1 $ c=1;((c++));echo $? 0 Only the above was reported, but this also yeilds more proof: $ for c in {-3..3};do ((c++));echo $? "${c}";done 0 -2 0 -1 0 0 1 1 0 2 0 3 0 4 Cheers AndrewM

5 years, 5 months

smaller pavucontrol

by Tim Connors

Is there a smaller version of pavucontrol that can access all the mixers and give a quick visual indication of current volume levels, but still fit on the screen when you have more than 5 or 6 audio applications open at once? -- Tim Connors

5 years, 5 months

Connecting to Wi-Fi, alternatives to network manager

by Mark Trickett

Hello All, Having a Telstra supplied Netgear Mobile modem, nominally a Telstra4GA device, I am not happy with the way that Network Manager connects, or fails, silently. What software and procedures do you use to connect to Wi-Fi networks? I am looking for something I can largely script, but also adapt to coping with connecting to other devices elsewhere now and then. I am also wanting something a little more informative and verbose, I may not initially understand all the returned information, but I can work on that. Regards, Mark Trickett

5 years, 5 months

SNMP monitoring

by Brian May

Hello, What is the easiest way of monitor SNMP data from a small number of VMs, servers, routers, switches and UPS? Previously I used zenoss for this. It is good in that I can tell it to monitor a switch, and I automatically get statistics recorded for every port on the switch (without having to configure each port manually). On the downside zenoss seems to be bulky and complicated at times. Or at least my legacy version (3.2.1-0) - I doubt this has changed although I might be mistaken. However I noticed that I am on a legacy version, and the latest version only seems to support RHEL/Centos based systems (my current install is on Debian). So considering that I might need to do a complete reinstall anyway, I thought I might us well check to seem what other options there are. http://wiki.zenoss.org/Install_Zenoss Thanks. -- Brian May <brian(a)linuxpenguins.xyz> https://linuxpenguins.xyz/brian/

5 years, 5 months

oom-killer being invoked instead of swapping

by Kim Oldfield

Hi, I have a raspberry pi 2 on which I recently installed Ubuntu 16.04.2. After the install oom-killer has been killing processes, even when there is 1GB of swap free. I would have expected the kernel to swap something out rather than killing processes. How can I use swap rather than having oom-killer killing processes? Here is a typical oom-kill as recorded by syslog: Apr 21 15:45:01 pi2 kernel: [72182.070173] sh invoked oom-killer: gfp_mask=0x24004c0, order=2, oom_score_adj=0 Apr 21 15:45:01 pi2 kernel: [72182.070196] sh cpuset=/ mems_allowed=0 Apr 21 15:45:01 pi2 kernel: [72182.070221] CPU: 2 PID: 10341 Comm: sh Not tainted 4.4.0-1052-raspi2 #59-Ubuntu Apr 21 15:45:01 pi2 kernel: [72182.070228] Hardware name: BCM2709 Apr 21 15:45:01 pi2 kernel: [72182.070265] [<80111e94>] (unwind_backtrace) from [<8010d100>] (show_stack+0x20/0x24) Apr 21 15:45:01 pi2 kernel: [72182.070286] [<8010d100>] (show_stack) from [<8056a52c>] (dump_stack+0xc8/0x10c) Apr 21 15:45:01 pi2 kernel: [72182.070308] [<8056a52c>] (dump_stack) from [<802a888c>] (dump_header+0x68/0x1c8) Apr 21 15:45:01 pi2 kernel: [72182.070327] [<802a888c>] (dump_header) from [<80247800>] (oom_kill_process+0x36c/0x4b4) Apr 21 15:45:01 pi2 kernel: [72182.070344] [<80247800>] (oom_kill_process) from [<80247bb8>] (out_of_memory+0x1f8/0x35c) Apr 21 15:45:01 pi2 kernel: [72182.070361] [<80247bb8>] (out_of_memory) from [<8024d93c>] (__alloc_pages_nodemask+0xd38/0xd78) Apr 21 15:45:01 pi2 kernel: [72182.070378] [<8024d93c>] (__alloc_pages_nodemask) from [<8024d99c>] (__get_free_pages+0x20/0x64) Apr 21 15:45:01 pi2 kernel: [72182.070395] [<8024d99c>] (__get_free_pages) from [<801190d4>] (pgd_alloc+0x28/0x11c) Apr 21 15:45:01 pi2 kernel: [72182.070411] [<801190d4>] (pgd_alloc) from [<80121520>] (mm_init+0xd8/0x170) Apr 21 15:45:01 pi2 kernel: [72182.070427] [<80121520>] (mm_init) from [<80121bbc>] (mm_alloc+0x5c/0x68) Apr 21 15:45:01 pi2 kernel: [72182.070445] [<80121bbc>] (mm_alloc) from [<802b3ecc>] (do_execveat_common+0x280/0x744) Apr 21 15:45:01 pi2 kernel: [72182.070463] [<802b3ecc>] (do_execveat_common) from [<802b4624>] (SyS_execve+0x40/0x48) Apr 21 15:45:01 pi2 kernel: [72182.070481] [<802b4624>] (SyS_execve) from [<80108c60>] (ret_fast_syscall+0x0/0x1c) Apr 21 15:45:01 pi2 kernel: [72182.070489] Mem-Info: Apr 21 15:45:01 pi2 kernel: [72182.070510] active_anon:7968 inactive_anon:36348 isolated_anon:0 Apr 21 15:45:01 pi2 kernel: [72182.070510] active_file:35828 inactive_file:127471 isolated_file:0 Apr 21 15:45:01 pi2 kernel: [72182.070510] unevictable:0 dirty:5 writeback:0 unstable:0 Apr 21 15:45:01 pi2 kernel: [72182.070510] slab_reclaimable:15804 slab_unreclaimable:4482 Apr 21 15:45:01 pi2 kernel: [72182.070510] mapped:4644 shmem:1239 pagetables:434 bounce:0 Apr 21 15:45:01 pi2 kernel: [72182.070510] free:2363 free_pcp:0 free_cma:15 Apr 21 15:45:01 pi2 kernel: [72182.070554] Normal free:9452kB min:3836kB low:4792kB high:5752kB active_anon:31872kB inactive_anon:145392kB active_file:143312kB inactive_fi le:509884kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:966656kB managed:942128kB mlocked:0kB dirty:20kB writeback:0kB mapped:18576kB shmem:4956kB slab_r eclaimable:63216kB slab_unreclaimable:17928kB kernel_stack:1656kB pagetables:1736kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:60kB writeback_tmp:0kB page s_scanned:16 all_unreclaimable? no Apr 21 15:45:01 pi2 kernel: [72182.070563] lowmem_reserve[]: 0 0 Apr 21 15:45:01 pi2 kernel: [72182.070577] Normal: 1251*4kB (UME) 579*8kB (UME) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 9636kB Apr 21 15:45:01 pi2 kernel: [72182.070625] 165625 total pagecache pages Apr 21 15:45:01 pi2 kernel: [72182.070635] 1119 pages in swap cache Apr 21 15:45:01 pi2 kernel: [72182.070643] Swap cache stats: add 23103, delete 21984, find 25546/29364 Apr 21 15:45:01 pi2 kernel: [72182.070650] Free swap = 1004812kB Apr 21 15:45:01 pi2 kernel: [72182.070656] Total swap = 1048572kB Apr 21 15:45:01 pi2 kernel: [72182.070663] 241664 pages RAM Apr 21 15:45:01 pi2 kernel: [72182.070669] 0 pages HighMem/MovableOnly Apr 21 15:45:01 pi2 kernel: [72182.070675] 6132 pages reserved Apr 21 15:45:01 pi2 kernel: [72182.070681] 2048 pages cma reserved Apr 21 15:45:01 pi2 kernel: [72182.070688] [ pid ] uid tgid total_vm rss nr_ptes nr_pmds swapents oom_score_adj name Apr 21 15:45:01 pi2 kernel: [72182.070717] [ 345] 0 345 1225 228 6 0 40 0 systemd-journal Apr 21 15:45:01 pi2 kernel: [72182.070730] [ 383] 0 383 3124 36 7 0 3 0 lvmetad Apr 21 15:45:01 pi2 kernel: [72182.070744] [ 431] 0 431 2997 145 8 0 128 -1000 systemd-udevd Apr 21 15:45:01 pi2 kernel: [72182.070758] [ 684] 100 684 3064 123 7 0 28 0 systemd-timesyn Apr 21 15:45:01 pi2 kernel: [72182.070771] [ 701] 0 701 592 38 6 0 4 0 rpc.idmapd Apr 21 15:45:01 pi2 kernel: [72182.070783] [ 805] 0 805 834 287 6 0 33 0 systemd-logind Apr 21 15:45:01 pi2 kernel: [72182.070796] [ 808] 0 808 346 63 5 0 3 0 acpid Apr 21 15:45:01 pi2 kernel: [72182.070808] [ 815] 0 815 1130 129 7 0 19 0 cron Apr 21 15:45:01 pi2 kernel: [72182.070821] [ 819] 0 819 7684 292 10 0 1 0 lxcfs Apr 21 15:45:01 pi2 kernel: [72182.070834] [ 822] 107 822 1226 296 6 0 48 -900 dbus-daemon Apr 21 15:45:01 pi2 kernel: [72182.070846] [ 831] 104 831 7794 168 9 0 122 0 rsyslogd Apr 21 15:45:01 pi2 kernel: [72182.070859] [ 833] 0 833 9084 635 12 0 63 0 accounts-daemon Apr 21 15:45:01 pi2 kernel: [72182.070871] [ 836] 0 836 712 55 6 0 33 0 atd Apr 21 15:45:01 pi2 kernel: [72182.070883] [ 854] 0 854 8711 305 13 0 57 0 polkitd Apr 21 15:45:01 pi2 kernel: [72182.070896] [ 1002] 113 1002 29479 1911 30 0 4528 0 named Apr 21 15:45:01 pi2 kernel: [72182.070909] [ 1012] 0 1012 1997 225 7 0 104 -1000 sshd Apr 21 15:45:01 pi2 kernel: [72182.070922] [ 1015] 114 1015 2560 865 10 0 945 0 dhcpd Apr 21 15:45:01 pi2 kernel: [72182.070935] [ 1045] 0 1045 1359 97 6 0 80 0 rpcbind Apr 21 15:45:01 pi2 kernel: [72182.070948] [ 1049] 0 1049 1420 516 6 0 119 0 rpc.mountd Apr 21 15:45:01 pi2 kernel: [72182.070962] [ 1143] 0 1143 832 118 6 0 17 0 irqbalance Apr 21 15:45:01 pi2 kernel: [72182.070974] [ 1170] 0 1170 862 61 5 0 25 0 agetty Apr 21 15:45:01 pi2 kernel: [72182.070987] [ 1172] 0 1172 908 10 6 0 19 0 agetty Apr 21 15:45:01 pi2 kernel: [72182.071000] [ 1254] 0 1254 10969 1791 16 0 710 0 fail2ban-server Apr 21 15:45:01 pi2 kernel: [72182.071012] [ 1263] 0 1263 2225 1240 8 0 45 0 apache2 Apr 21 15:45:01 pi2 kernel: [72182.071025] [ 1358] 0 1358 7968 143 9 0 65 0 master Apr 21 15:45:01 pi2 kernel: [72182.071037] [ 1360] 112 1360 8020 335 9 0 45 0 qmgr Apr 21 15:45:01 pi2 kernel: [72182.071050] [ 1716] 1000 1716 1581 32 8 0 409 0 systemd Apr 21 15:45:01 pi2 kernel: [72182.071062] [ 1720] 1000 1720 1813 33 7 0 397 0 (sd-pam) Apr 21 15:45:01 pi2 kernel: [72182.071075] [ 1912] 0 1912 2945 119 11 0 165 0 sshd Apr 21 15:45:01 pi2 kernel: [72182.071088] [ 1946] 1000 1946 4041 1235 14 0 146 0 sshd Apr 21 15:45:01 pi2 kernel: [72182.071100] [ 1947] 1000 1947 36295 35191 75 0 10 0 unison Apr 21 15:45:01 pi2 kernel: [72182.071114] [ 6694] 33 6694 58348 900 36 0 45 0 apache2 Apr 21 15:45:01 pi2 kernel: [72182.071127] [ 6695] 33 6695 58092 899 36 0 45 0 apache2 Apr 21 15:45:01 pi2 kernel: [72182.071141] [10335] 112 10335 7986 721 8 0 0 0 pickup Apr 21 15:45:01 pi2 kernel: [72182.071153] [10337] 0 10337 1470 504 7 0 5 0 cron Apr 21 15:45:01 pi2 kernel: [72182.071166] [10338] 1000 10338 365 101 4 0 0 0 sh Apr 21 15:45:01 pi2 kernel: [72182.071179] [10339] 1000 10339 3084 2179 10 0 0 0 optus-status Apr 21 15:45:01 pi2 kernel: [72182.071191] [10340] 1000 10340 365 93 5 0 0 0 sh Apr 21 15:45:01 pi2 kernel: [72182.071203] [10341] 1000 10341 365 16 4 0 0 0 sh Apr 21 15:45:01 pi2 kernel: [72182.071212] Out of memory: Kill process 1947 (unison) score 70 or sacrifice child Apr 21 15:45:01 pi2 kernel: [72182.078994] Killed process 1947 (unison) total-vm:145180kB, anon-rss:139988kB, file-rss:776kB Apr 21 15:45:02 pi2 systemd[1]: Stopping User Manager for UID 1000... Apr 21 15:45:02 pi2 systemd[1716]: Stopped target Default. Apr 21 15:45:02 pi2 systemd[1716]: Reached target Shutdown. Apr 21 15:45:02 pi2 systemd[1716]: Stopped target Basic System. Apr 21 15:45:02 pi2 systemd[1716]: Stopped target Paths. Apr 21 15:45:02 pi2 systemd[1716]: Stopped target Sockets. Apr 21 15:45:02 pi2 systemd[1716]: Stopped target Timers. Apr 21 15:45:02 pi2 systemd[1716]: Starting Exit the Session... Apr 21 15:45:02 pi2 systemd[1716]: Received SIGRTMIN+24 from PID 10345 (kill). Apr 21 15:45:02 pi2 systemd[1]: Stopped User Manager for UID 1000. Apr 21 15:45:02 pi2 systemd[1]: Removed slice User Slice of kim.

5 years, 5 months

itpol/linux-workstation-security.md at master · lfit/itpol

by Andrew McGlashan

Hi All, An interesting resource, there are other policies and if you go up the chain, there are other github projects too. This is from Linux Foundation (fwiw), enjoy! - lfit "Linux Foundation IT" https://github.com/lfit/itpol/blob/master/linux-workstation-security.md -- Kind Regards AndrewM Andrew McGlashan IT Support & Broadband Solutions

5 years, 5 months

Battery from old ASUS Eee PC 1000HE or similar?

by Andrew McGlashan

Hi, The laptop fell apart, I've been told that it was common with that model... Anyway, the laptop has been disposed of, but I kept the battery just in case someone had a use for it. I can't really vouch for the health of the battery because it hasn't been used for a long time now. Other details: +7.2V 8700mAH 62Wh Let me know off list if you like. -- Kind Regards AndrewM

5 years, 5 months

April beginners meeting rescheduling proposal

by Andrew Pam

Given that the third Saturday this month is actually Easter Saturday when many members will not be able to attend, the committee is considering rescheduling the beginners meeting for the following Saturday, 22 April. If this is a problem for anyone, please let us know! Once again, please do suggest any topics you'd like us to cover. Thanks, Andrew

5 years, 6 months

Computer architecture (Youtube) links after Stewart's talk

by Rodney Brown

David Patterson's (of RISC & RAID fame) "Instruction Sets Want To Be Free - A Case for RISC-V" https://www.youtube.com/watch?v=mD-njD2QKN0 ~1hr Slides https://sigops.org/sosp/sosp15/history/07-patterson-slides.pdf (Outline) Part I - Past 50 years of Computer Architecture History: . 1960s: Computer Families / Microprogramming . 1970s: CISC . 1980s: RISC . 1990s: VLIW . 2000s: NUMA vs. Clusters Part II - Future HW Technology . End of Moore's Law . Flash vs. Disks . Fast DRAM . Crosspoint NVRAM Open ISA & RISC-V . Case for Open ISAs ... Spruiking for RISC-Vo On stack computer's See :- Koopman, P.J. (1989) "Stack Computers: the new wave" Ellis Horward ISBN 0138379238 at https://users.ece.cmu.edu/~koopman/stack_computers/index.html https://users.ece.cmu.edu/~koopman/stack_computers/sec4_5.html 4.5 Architecture of the Harris RTX 2000 - Rosetta's Philae lander was powered by two 8MHz Harris RTX2010 16-bit stack processors Message of Linus Torvalds to Risc-V https://www.youtube.com/watch?v=q7C6mo1R8xU <3min 2016-10-13 - not directedly asked about RISC-V, ... Edited excerpt from the auto-generated transcript "it turns out the instruction set and the core of the CPU is not very important and and it's one of those big differentiating factors that people kind of fixate on but it really doesn't matter very much in the end. What matters is all the infrastructure around that instruction set and an x86 right now has all that infrastructure and it has it at a lot of different levels. ... I tend to look for is making if you want to make big progress in a specific area you need to figure out how to make lots of people care about that specific area and and that's the problem with small devices right now is it's really hard to find lots of people to care when most of the small devices you can buy tend to be very locked down for example and and I'd love to say that there's millions and millions of IOT devices that there should be tons of people caring about them but if all these IOT devices are actually hard to play with the only people who end up caring about these are inside companies and it's really hard to get a personal interest in small hardware when none of the small hardware really tends to encourage that kind of loving"

5 years, 6 months

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luv-main April 2017