September 2017 - 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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Any Debian Developers here can help me sign my GPG key?
by tlugys.ats＠spamgourmet.com 26 Feb '18

26 Feb '18

Hi GTALUG members, Do we have any Debian Developers here? I am in the second step of becoming New Debian Maintainer process -- https://nm.debian.org/process/194 and now need to have my GPG key signed by a Debian member. I was directed to the THUG group (Toronto (GNU)/Hurd User Group) http://www.nongnu.org/thug/ but only to find that their listed email (thug(a)gnu.org) is no longer working. So I'm in a bad position now, and really hope that there is a Debian Developer here, or you know of, that can help me. I live in GTA, North York to be exactly. Any help can comfort my desperate heart. Thanks Antonio

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Dead DVD drive in laptop
by Chris F.A. Johnson 04 Oct '17

04 Oct '17

The DVD drive on my Dell Inspiron laptop has died. I see three options: 1. Get it fixed 2. Replace it 3. Ignore it and get an external DVD Which would you recommend? (I'm running Linux Mint.) -- Chris F.A. Johnson, <http://cfajohnson.com>

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Firefox memory usage (was GTALUG Meeting on Tuesday 10 October at 7:30pm)
by Myles Braithwaite 👾 01 Oct '17

01 Oct '17

o1bigtenor via talk wrote: > Am a serious browser user - - - in the past have had up to 18 windows > open and from 3 to 50+ tabs on any one window. There isn't a browser out > there that can handle that kind of usage especially NOT FF! ( I have > north of 20 GB of RAM plus a system to match so its really not a > resources issue). The issue is that browsers are quite memory wasteful > and somehow can't use ram neatly. When can we expect the present malaise > to change - - - - 2030? > > Maybe his response to my comment/question could be transmitted back - - > - please? > > Yes I've tried using the 'help' section but dev types don't seem to ever > read anything there. Resource usage in web browsers depend on a given web site. The greatest example is The Verge[0] a technology blog that requires 274 HTTP requests and 3.0 MB of data[1]. According to the Firefox extension Tab Data[2] on first load that take ~30MB of RAM and comes down to ~17MB after all the requests get processed. Interesting side note this article[3] can use anywhere from 40MB to 100MB of RAM. Browser developers build better optimized browsers while web developers make heavy web pages which use up all the resources (usually with ads). Extensions also take out a lot of memory as while, checkout about:memory. Though your question is warranted, it's not really appropriate as it will result a bunch of questions from the speaker (i.e. what web sites are you visiting, how many extensions are you using, what's your internet connection, etc). [0]: <https://www.theverge.com/> [1]: <https://tools.pingdom.com/#!/dbE4hE/https://www.theverge.com/> [2]: <https://addons.mozilla.org/en-US/firefox/addon/tab-data/> [3]: <https://www.theverge.com/2017/9/29/16387706/wonder-woman-batman-dc-expanded…>

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[GTALUG-Announce] GTALUG Meeting on Tuesday 10 October at 7:30pm
by hi＠gtalug.org 01 Oct '17

01 Oct '17

<http://gtalug.org/meeting/2017-10/> # The State of Mozilla with Mike Hoye In November, Mozilla will release Firefox 57, a major update to the browser with a lot of new technology and features under the hood. Mike Hoye will be joining us to talk where Firefox, Mozilla and the Web are today, and where they're going. ### Annual General Meeting After Mike's talk GTALUG will be doing it's annual general meeting. * **GTALUG Update** -- 5 minutes * **Treasury Update** -- 5 minutes * **ICANN & CAG** -- 5 minutes * **Board Elections** -- 20 minutes ## Location George Vari Engineering and Computing Centre 245 Church Street, Room 203 Ryerson University <http://goo.gl/maps/16oJ2> <http://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: <http://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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Programming Atmel Microprocessor from Linux
by phiscock＠ee.ryerson.ca 29 Sep '17

29 Sep '17

I'm currently developing a program in assembly language, using a Linux platform to host the development. The development environment is very simple. My notes on this are now on my academic web page at http://www.ee.ryerson.ca/~phiscock/ in the 'papers' subdirectory. Peter -- Peter Hiscocks Syscomp Electronic Design Limited, Toronto http://www.syscompdesign.com USB Oscilloscope and Waveform Generator 647-839-0325

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Wireshark question -- script to extract data in TCP stream?
by William Park 28 Sep '17

28 Sep '17

To network experts... >From Wireshark, I can click "TCP Follow" tab and extract one-way data flow from a tcp stream. I can do this manually, one by one. But, I have many many streams. Does anyone know how to extract one-way data stream via script? Google says tshark -q -r capture.pcapng -z follow,tcp,raw,0 where '0' is the tcp stream number 0. But, it gives me data moving both ways. I just want data moving one-way. -- William Park <opengeometry(a)yahoo.ca> .

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SUSE Linux turns 25: From business distro leader to cloud power | ZDNet
by James Knott 26 Sep '17

26 Sep '17

"SUSE, one of the oldest Linux and open-source businesses, celebrated its 25th birthday while setting its eyes on its future in the cloud and software-defined infrastructure." http://www.zdnet.com/article/suse-linux-at-25/

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Big banks and telcos backing digital identity supercluster bid | IT World Canada News
by James Knott 23 Sep '17

23 Sep '17

I wonder if they'll provide X.509 certificates for individuals. While many people use them (and some use PGP/GPG) the big issue for so many is convenience. In companies that use a directory server, it's a simple matter to get the certificates for anyone else in the company, making it real easy to send encrypted email. Otherwise, you have to arrange for certs on your own and then send a signed message, so that the other person can send you an encrypted email. Of course, many people haven't even heard of email encryption. A few years ago, CIBC was offering X.509 certificates for customers, but I believe they could only be used for banking business, such as applying for loans etc. I don't know if they're still doing it. What we need for encrypted email to really take off is a server where you can automatically find anyone's public certificate, when you send an email, just as can be done with directory servers. BTW, my first experience with this was at IBM, 20 years ago, when the Lotus Notes servers supplied the certificates to anyone sending email. Previously, I had experimented with PGP, as others at the OS/2 users group had, but never really used it for much. http://www.itworldcanada.com/article/big-banks-and-telcos-backing-superclus…

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war story: EFI System Partition is fragile
by D. Hugh Redelmeier 15 Sep '17

15 Sep '17

The EFI System Partition (EEFS) is an important component in a UEFI-booting system. The EFS is a FAT32 partition that contains all the programs that can be run by the firmware. So to boot Windows or Linux, the system runs some *.efi files from this partition. FAT32 isn't a very forgiving filesystem. I just had one damaged by Windows updates. I was left with a system that just went to a grub prompt when booted. Diagnosis: I booted a live Fedora USB stick. First I had to figure out which partition was the EFS. I did that by using "disks" (gnome-disk-utility). There might have been lighter-weight tools, but I'm used to this one. I did an fsck on the partition. Lots of bad news. "Fixing" resulted in grubenv and grub.cfg becoming empty. This, of course, left grub quite confused and ignorant. Fixing: I did some tricky things, as advised by the internet. They might only work because the live USB stick's Fedora matched the installed Fedora in some way. The general idea is to create a chroot world with the Disk's system (bur running the USB stick's kernel). Then use grub2-miconfig to install a new and useful grub.cfg in the EFS. - mount all the necessary partitions of the disk system + root on /mnt/x + I don't have a /boot partition but many would + EFS on /mnt/x/boot/efi + home on /mnt/x/home + swap is already handled. Use bind mounts to create necessary bit: mount -bind /dev /mnt/x/dev mount -bind /sys /mnt/x/sys mount -bind /proc /mnt/x/proc get into this world su chroot /mnt/x fix the grub.cfg su chroot /mnt/x cd /boot/EFI/fedora ls -l grub.cfg grub2-mkconfig -o grub.cfg It should now be fixed, but do have a look around for other problems. Lessons: - /boot/efi is fragile. - Consider backing it up. - Consider leaving it unmounted at rest.

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