February 2019 - Talk - lists.gtalug.org

war story: power failure makes CentOS system unbootable
by D. Hugh Redelmeier 30 Sep '22

30 Sep '22

tl;dr / spoiler: change fstab so that /boot/efi is not automatically mounted. See the recommendation at the end of this message. My gateway computer is a little PC running CentOS. It does not come back after a power failure. The reason (as best I can tell) is interesting and I think that I have a fix. My system is UEFI. It boots from a UEFI system partition, known as /boot/efi to Linux. If this gets corrupted, it won't boot. It is a VFAT partition. On my gateway (a Zotac Zbox RI321, a cute little box with two ethernet ports), the UEFI firmware apparently won't boot if the dirty bit is set in the system partition. CentOS normally runs with /boot/efi mounted. So when the system isn't shut down cleanly, the dirty bit will be on. Consequence: the system is not going to boot after a power failure. Odd observation 1: if I put a live Fedora 25 USB stick in the system and try to boot in this otherwise-unbootable state, CentOS boots from the main disk. So this really looks like a firmware bug/quirk. Odd observation 2: fsck doesn't seem to automatically fix the system partition. Once CentOS 7 booted, I dismounted /boot/efi and did an fsck on it. $ sudo fsck /dev/sda1 fsck from util-linux 2.23.2 fsck.fat 3.0.20 (12 Jun 2013) 0x25: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt. 1) Remove dirty bit 2) No action ? 1 Leaving filesystem unchanged. /dev/sda1: 16 files, 2420/51145 clusters Googling got me to <https://www.centos.org/forums/viewtopic.php?t=50917> In particular, this advice seemed quite good: ==== recommendation ==== Two other changes I recommend for UEFI systems, to each OS's /etc/fstab. - For the /boot/efi mountpoint, add the mount options x-systemd.automount,noauto - Change fs_passno (last column) to a 1 or 2; the canonical fstab instructions suggest 2, but systemd treats 1 and 2 as the same. The first change means the EFI System partition will not be automatically read-write mounted at boot time; it's a bad idea this is the default because it puts the ESP at risk especially if ther are crashes, FAT has no journal and will therefore always be marked dirty in such a case; no other UEFI OS mounts the ESP by default. Second, if anything tries to access /boot/efi (read or write), systemd will automatically mount it, and because of the fs_passno 1 or 2, it will fsck it first and that fixes and clears the dirty bit in case it's set. Right now without these changes, it's just a matter of having the right number and bad timing of crashes to render the EFI System partition corrupt.

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[GTALUG-Announce] GTALUG Meeting Feburary 12th at 7:30pm
by hi＠gtalug.org 11 Mar '19

11 Mar '19

<https://gtalug.org/meeting/2019-02/> # FPGAs for Fun, Acceleration, and Profit! w/ Chris Tyler Field Programmable Gate Arrays (FPGAs) have moved from being expensive, exotic prototyping tools to affordable mainstream devices for hardware customization and acceleration. This talk takes a general look at FPGAs, how to use them, the current technology landscape, the increasing use of FPGAs as cloud, leaf, and server accelerators, and related technology initiatives around standardization and cache coherence. ## Location George Vari Engineering and Computing Centre 245 Church Street, Room 203 Ryerson University <https://goo.gl/maps/16oJ2> <https://www.openstreetmap.org/way/23447525> ## Schedule * 6:00 pm - Please discuss on the general mailing list (i.e. <talk(a)gtalug.org>) where you want to go for dinner. * 7:30 pm - Meeting and presentation. * 9:00 pm - After each meeting, a group of GTALUGers move to The Imperial Pub (54 Dundas St East) for refreshments and more socialising. # Code of Conduct We want a productive happy community that can welcome new ideas, improve every process every year, and foster collaboration between individuals with differing needs, interests and skills. We gain strength from diversity, and actively seek participation from those who enhance it. This code of conduct exists to ensure that diverse groups collaborate to mutual advantage and enjoyment. We will challenge prejudice that could jeopardise the participation of any person in the community. The Code of Conduct governs how we behave in public or in private whenever the Linux community will be judged by our actions. We expect it to be honoured by everyone who represents the community officially or informally, claims affiliation or participates directly. It applies to activities online or offline. We invite anybody to participate. Our community is open. Please read more about the GTALUG Code of Conduct here: <https://gtalug.org/about/code-of-conduct/>. If you have any questions, comments, or concerns about the GTALUG Code of Conduct please contact the GTALUG Board @ <board(a)gtalug.org>. --- GTALUG Announce mailing list announce(a)gtalug.org https://gtalug.org/mailman/listinfo/announce

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Pine Book Pro
by Alex Volkov 04 Mar '19

04 Mar '19

Hey Everyone, It looks like Pine64 are releasing Pinebook Pro, a laptop that I'm actually willing to pay money for and then use. https://forum.pine64.org/showthread.php?tid=7093&pid=43850#pid43850 Specs: * 14" 1080p IPS LCD panel * 64/128GB of eMMC storage* * Black magnesium alloy body * SD card slot * Digital video output via USB-C up to 4K60hz * Audio aux out / UART * USB 3.0 and USB 2.0 ports * 802.11ac WiFi * Bluetooth 4.2 * 4GB of LPDDR4 RAM * Charging via barrel port or USB-C * Rockchip RK3399 ; big.LITTLE Hexacore A72/A53 SOC * 2mpx front-facing camera * Microphone * Speakers * Slim and slick design with minimal branding * PCIe x4 that can take a m.2 NVMe SSD using an optional adapter * Target Price: $199 Looking on the picture the things I like: * Regular keyboard with thick keys and minimal amount of weirdness (the location of 'Delete' button is questionable, but I'll live with that. * 1080p IPS scree should be pretty nice * NVM.e slot At least I can definitely replace my acer chrome book 11, which works when I need a very light computer in a pinch to dump video from my camera or browse the web, but not much else. I'm hoping that the product would be successful enough that there's going to be a release of a version with 8GB of RAM -- that would put it on par with ultrabooks. Thought I don't think Pinebook Pro ever going to meet its $200 US target price. Thoughts? Alex.

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Spamhaus block
by Marc Lijour 28 Feb '19

28 Feb '19

Does anyone has insights about dealing with Spamhaus? I'm getting increasingly frustrated by being listed without explanation. I run a very low bandwidth mail server and a website for my business. I am running postfix with SPF, DKIM, and DMARC. I'd like to know what I am missing. Spamhaus is very popular which in turn affects Twitter, LInkedIn, beyond just the mail. Is it possible to run one's own mail server this days?

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optimum swap size
by Gary 28 Feb '19

28 Feb '19

I have kubuntu 18.04 with 20 gigs ram. Does anyone know what the optimum size swap area that I should have? Currently, my swap partition is 2 gigs. Can I increase that by creating a swap file in addition to the swap partition? /gary

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Co-op Issues
by nick 23 Feb '19

23 Feb '19

Greetings All, I don't know if someone would be willing to give some advice on finding Co-op. For the last two semesters including semester I've been looking and found very little for my skills. Don't know what's up as literally getting in contact with folks at AMD got me contacts. Maybe someone has experience with the CO-OP program either hiring or otherwise. If someone wants a resume that's fine I would prefer to send it directly rather than to a public list through, Nic

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Re: [GTALUG] Spamhaus block
by Val Kulkov 22 Feb '19

22 Feb '19

On Fri, 22 Feb 2019 at 00:36, ac via talk <talk(a)gtalug.org> wrote: > > Do not expect to be able to relay email communications properly, from > such a poor IP neighborhood. > Most or all participants to this thread appear to agree that picking the right IP neighbourhood is key to success. So, how does one pick a good neighbourhood? Are there any tried-and-true rules or methods?

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Power over Ethernet question
by Russell Reiter 22 Feb '19

22 Feb '19

The Ontario Electrical Safety Authority has recently ratified Power over Ethernet for domestic residential LED lighting and associated home control systems. I was just wondering if anybody on the list is using PoE for lighting and has any recommendations on which types of LED's are best for general use. I have a 45w grow light for an African violet but the light it casts gives a kind of institutional feeling. I'm not sure I'd want it everywhere. I live in apartment with older ceiling fixtures and currently screw-in compact fluorescent bulbs last a year or so before the transformer dies from voltage spikes. Ostensibly this is from being on the same sub-panel as switched loads, fans, ac and the fridge being the main culprits. Any suggestions and anecdotes are appreciated. TIA Russell

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IP mystery
by Darryl Moore 21 Feb '19

21 Feb '19

Hello LUGgers. Here is an interesting mystery for anyone interesting. I'd love if anyone could explain it. The following is cut and paste directly from my bash session and not edited in anyway. What the $*#$^ is going on here? I have reset all the routers between these two machines in case somehow they were responding to ARP requests instead of the target machine. I've done everything except for resetting the target itself. Also I have a daemon on the target which is doing 'C' system calls with getifaddrs(&ifap) library calls and it reports back both 192.168.11.50 and 192.168.11.133 even though ifconfig does not. Anybody have a clue what is going on here? cheers, Darryl ---------------------------------- darryl@darryl-Aspire-V3-575:~$ darryl@darryl-Aspire-V3-575:~$ darryl@darryl-Aspire-V3-575:~$ darryl@darryl-Aspire-V3-575:~$ ssh root(a)192.168.11.133 Warning: Permanently added '192.168.11.133' (ECDSA) to the list of known hosts. Welcome to Ubuntu 16.04 LTS (GNU/Linux 4.4.0-64-generic i686) * Documentation: https://help.ubuntu.com/ 658 packages can be updated. 406 updates are security updates. New release '18.04.2 LTS' available. Run 'do-release-upgrade' to upgrade to it. You have new mail. Last login: Thu Feb 21 14:45:01 2019 from 192.168.11.127 root@elp123456:~# ifconfig eth0 Link encap:Ethernet HWaddr 00:f1:f3:8f:05:7d inet addr:192.168.11.50 Bcast:192.168.11.255 Mask:255.255.254.0 inet6 addr: fe80::2f1:f3ff:fe8f:57d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1269911 errors:0 dropped:1065 overruns:0 frame:0 TX packets:682949 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:214230001 (214.2 MB) TX bytes:129622352 (129.6 MB) eth0:2 Link encap:Ethernet HWaddr 00:f1:f3:8f:05:7d inet addr:192.168.9.1 Bcast:192.168.9.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:2264301 errors:0 dropped:0 overruns:0 frame:0 TX packets:2264301 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1 RX bytes:1188627720 (1.1 GB) TX bytes:1188627720 (1.1 GB) tun0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 inet addr:10.8.1.245 P-t-P:10.8.1.245 Mask:255.255.0.0 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1 RX packets:214252 errors:0 dropped:0 overruns:0 frame:0 TX packets:214990 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:12935258 (12.9 MB) TX bytes:69517662 (69.5 MB) root@elp123456:~#

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FW: Problems with Ubuntu 18.10
by cdasilva＠iprimus.ca 20 Feb '19

20 Feb '19

Hello I am just resending this as I got ho responses Clive From: cdasilva(a)iprimus.ca <cdasilva(a)iprimus.ca> Sent: February 10, 2019 2:44 PM To: talk <talk-bounces(a)gtalug.org> Subject: Problems with Ubuntu 18.10 Hello I had a problem with my recent Ubuntu 18.10 install which I thought that I should share. I was running Ubuntu 18.04 on an older Pentium (R)Dual Core CPU E5200 with 4 gigs of ram and things went well. About 2 months ago, I noticed that there was an Ubuntu 18.10 so I thought that I would give it a try. So I downloaded Ubuntu 18.10 with kernel 4.18.0.10 and it worked well with all my machine learning stuff (Anaconda3, etc.). About 2 weeks ago, Ubuntu informed me that I had a kernel update so I downloaded the update (kernel 4.18.0.14) and tried to install it. Couldn't get past the boot screen, so I reinstalled 4.18.0.10 but right away I was informed of the waiting update. I googled the issue and the only comment that made sense was to block Wayland being loaded and instead default to Xorg by adjust custom.conf \etc\gdm3. That made no difference to my situation as described After about a week of tearing my hair, I gave up and went back to Ubuntu 18.04 LTS, and am just sharing this in the event that any of you have had a similar experience with Ubuntu 18.10 (in my case - desktop). Please feel free to comment -------------------- Clive Dasilva cdasilva(a)iprimus.ca <mailto:cdasilva@iprimus.ca> Ubuntu 18.04LTS

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