June 2019 - Talk - lists.gtalug.org

[GTALUG-Announce] Meeting Tomorrow at 7:30pm
by hi＠gtalug.org 10 Jun '19

10 Jun '19

<https://gtalug.org/meeting/2019-06/> # MyRocks 101 You may have heard about MyRocks, the new implementation of log structured merge indexing via RocksDB for MySQL But what is it? How does it work? What’s it good for? What is this thing called compaction? In this session we’re going to explore the high level mechanics as well as common system variables, column family options, and associated metrics so that you’ll have the familiarity you need for this emerging storage engine. ## 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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[GTALUG-Announce] MyRocks 101
by hi＠gtalug.org 10 Jun '19

10 Jun '19

<https://gtalug.org/meeting/2019-06/> # MyRocks 101 You may have heard about MyRocks, the new implementation of log structured merge indexing via RocksDB for MySQL But what is it? How does it work? What’s it good for? What is this thing called compaction? In this session we’re going to explore the high level mechanics as well as common system variables, column family options, and associated metrics so that you’ll have the familiarity you need for this emerging storage engine. ## 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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GNU Cauldron for GCC This Year
by nick 09 Jun '19

09 Jun '19

Greetings All, I was wondering if anyone else here is attending the GNU Cauldron this year for GCC. Just a little curious as seems I got a grant for it as a student and I know there is one or two other compiler developers in the group if I'm correct. Nick

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war story: fixing an LCD TV
by D. Hugh Redelmeier 07 Jun '19

07 Jun '19

My 39" UltraHD TV, the one that I used as my main computer monitor for almost four years, stopped working. The symptom was that it just would not turn on. The status light below the screen stayed red, meaning something like "standby". Normally it turns blue when I'm using it. Googling and watching YouTube videos convinced me that there was a chance that I could repair it. LCDs seem to have certain standard PC boards. - T-Con (timing control) - power supply - processor - LED light & video driver Replacement boards are reasonably inexpensive, apparently from chop shops (i.e. they buy broken TVs and sell the working parts). This shows someone fixing my model of TV. <https://www.youtube.com/watch?v=XD7rIEgYULI> >From my research, it seemed as if the most likely problem would involve the power supply module. I could get one for US$~20 + ~$20 for shipping. I opened up the monitor and examined the entrails. There was a burnt spot on the power supply board. I posted my problem to the BadCaps.com forum and got encouragement that a little bit of solder would fix the board. I tried this, and it worked. At least for now. I'm using the monitor to compose this mail. <https://www.badcaps.net/forum/showthread.php?p=898646> I spent several hours researching and perhaps an hour disassembling, soldering, and reassembling. It might not have been worth that time given the value of the monitor ($350 original price, but used for 4 years and obsolete). I find it satisfying to fix a hardware problem, even though I'm a software guy. Summary: not all hardware problems are hard.

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[OT] mySQL help
by Stephen 04 Jun '19

04 Jun '19

I am not on any lists for mysql. So I thought that I would ask her, Suggestions for a help list for mysql are most welcome. I have a LAMP for web site development and rarely need to touch the database admin stuff. It has been years. I am creating a new site with database but I can't get the user to have privileges. Can anyone spot what is wrong? So I connect to the server with: stephen@Avalon:~$ mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 11 Server version: 5.7.26-0ubuntu0.18.04.1 (Ubuntu) Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> =========================================== I create grants mysql> grant all on rois3324_stephen.* to "rois3324_stephen"@"localhost" with grant option; Query OK, 0 rows affected (0.00 sec) =========================================== I try to see grants mysql> "rois3324_stephen"@"localhost" -> It looks like no grants were created. And I get a confirming error from PHP. Can anyone see what is wrong? Thank you! -- Stephen

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Nvme thermal throttling
by Russell Reiter 03 Jun '19

03 Jun '19

I'd posted information regarding M.2 Nvme heating and file transfer times on another thread and I have since installed this heat-sink. It has made enough of a difference that I thought I'd update. https://www.newegg.ca/p/35Y-005D-00007?Item=9SIADDZ6YW3437 While the sales blah said it is mandatory to use the supplied thermal pads, it came with three pads layered in plastic backing and no instructions. I used the two thinner pink ones and didn't realize at the time that the thicker blue one came apart as little blue squares. On reflection it looks like these were intended for padding the backing-plane around the chips because the sales picture show's a blue pad protruding from the end of the enclosure but I'd have to remove it from the slot again to reapply those pads. It was trickier to install this go around with my slightly arthritic fingers and all that bulk around it so I'm waiting on that. This copy from a 512GiB WD Black Nvme in a USB-C enclosure was done using pipe viewer in the console as opposed to the Nautilus file widget. So in comparing apples to oranges ymmv but the previous Nautilus copy from my installed SSD which was formatted to ext4 took almost 15 minutes, slowing to 95MiB/s about two thirds of the way through the copy. This copy from a NTFS file system on Nvme in an external enclosure via USB-C happened in 4min and hardly wavered from 500MiB/s. [R3eiter@archon ~]$ pv /run/media/R3eiter/..path to 512GiB USB-C../backup.tar.gz > /run/media/R3eiter/..path to 1TB Nvme../backup.tar.gz 118GiB 0:03:56 [ 512MiB/s] [================================>] 100% However copying from one place to another on the 1TB Nvme seems to have crunched it's on-board cache. In the last minute of this copy, speed dropped from around 500MiB/s to 25MiB/s with an occasional leap up to 475MiB/s. [R3eiter@archon ~]$ pv /run/media/R3eiter/DATA/Nvme/bak/backup.tar.gz > /run/media/R3eiter/DATA/Nvme/backup.tar.gz 118GiB 0:06:35 [ 307MiB/s] [================================>] 100% Booting from Nvme sure is is quick. I took Hugh's advice and masked PolicyKit in order to deal with a very slow shutdown watchdog on rebooting. I also masked Plymouth, this shaved the total boot time down a bit more than a second. Around ten seconds on the SSD and 7 seconds on the Nvme. F30 seems to have glossed over the grub boot screen while the Plymouth graphics widget was chewing up almost 3 seconds. I only left PolicyKit active long enough to install a proprietary Nvidia driver which is now available from the software apps repo for F30. I did this because F30 now defaults to Wayland which doesn't play well with Nvidia cards. Hopefully this will change. I used the F30 software install app to do this Nvidia update because I had a very odd experience with the gui for the bios setup. After my last firmware update I had to enable VT-d in bios from the keyboard without the mouse plugged in order to stop the output freezing. There was also a problem with cold booting the OS (when I upgraded F27 to 28 and then 29) while a tv was plugged into the Nvidia card via hdmi and a monitor on display port. Not being able to decide which output of the Nvidia card to recognize, the system woke neither. Heres what my current Fedora 30 startup info shows. [R3eiter@archon ~]$ sudo systemd-analyze Startup finished in 1.257s (kernel) + 1.413s (initrd) + 4.429s (userspace) = 7.101s graphical.target reached after 4.421s in userspace [R3eiter@archon ~]$ sudo systemd-analyze blame 2.484s systemd-udev-settle.service 609ms dracut-initqueue.service 573ms initrd-switch-root.service 569ms lvm2-monitor.service 527ms systemd-logind.service 412ms firewalld.service 360ms akmods.service 302ms udisks2.service 296ms libvirtd.service 251ms systemd-resolved.service 224ms systemd-machined.service 205ms lvm2-pvscan@259:2.service 198ms sssd.service 187ms systemd-udevd.service 173ms systemd-journal-flush.service 148ms systemd-journald.service 129ms dracut-pre-pivot.service 127ms user(a)42.service 108ms ModemManager.service 106ms upower.service 96ms avahi-daemon.service 94ms user(a)1000.service 85ms bluetooth.service This post is obviously more seat of the pants than science, but there are very few situations where a user can see with the naked eye that performance was sub-optimal. This was one of them.

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SSH Host tab completion
by Daniel Wayne Armstrong 03 Jun '19

03 Jun '19

Hello all ... I am currently running Debian Buster and Bash shell. I have a few Host aliases defined in my ~/.ssh/config. Example: Host test-server. So when, in console, I type ... $ ssh tes ... and hit Tab, then auto-completion fills out ... $ ssh test-server When I try to do the same thing in a terminal (urxvt), tab completion does *not* work. The complete host alias has to be entered. *But* tab completion for ssh host aliases *does* work if entered within tmux running in the terminal. Any idea how I can get tab completion working for ssh host aliases in the terminal? -- Daniel Wayne Armstrong https://www.circuidipity.com <http://www.circuidipity.com> Accomplish the great task by a series of small acts. -- Lao Tzu

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