July 2018 - 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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glittery cheap but useless toy computers
by D. Hugh Redelmeier 30 Sep '18

30 Sep '18

The price of this looks very attractive: <https://www.zapals.com/nexbox-a95x-tv-box-4k-android-7-1-amlogic-s905w-quad…> - US$23.99, with free (very slow) shipping, probably no tax - only FullHD - 1G RAM, 8G eMMC (a little light) - Amlogic S905w: quad core Arm Cortex A53 processor; penta core Mali 450MP GPU. There are a lot of cheap boxes meant for running Kodi and this is one of them. Technically, they run Android and easily hook up to your TV. But they don't run Android TV (a subtle but important difference). Because of "Digital Rights Management", they cannot run Netflix at a good resolution. I don't remember if YouTube also limits them. So what's left? Unauthorized content discovered through Kodi plug-ins. I've never tried this. I understand that there is a large turnover in plug-ins as they get taken down. For TV use, I much prefer a Xiaomi Mi Box with genuine Android TV (US$70 from US Walmart). BUT. The raw hardware for these cheap boxes is interesting. Faster than a Raspberry Pi. And these come with a box, remote control, and power supply. Expandability and openness in general is a lot worse. The worst thing is that all their GPUs are proprietary (and a few other things too) so you cannot drop an ordinary Linux on them. I think that they all use uboot and device tree, but in an idiosyncratic way, adding to the difficulty. I bought a (less) cheap S912 box that I intend to play with. Apparently you can run Linux on these if you don't need video output. I won't give links because I don't know which efforts are the best.

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An LibreOffice question.
by Alvin Starr 05 Aug '18

05 Aug '18

Does anybody know how to display and work with SI numbers like 10k or 20M or 40G within LIbreOffice? I have had little luck searching with google et al. While I am at it how about engineering notation? -- Alvin Starr || land: (905)513-7688 Netvel Inc. || Cell: (416)806-0133 alvin(a)netvel.net ||

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Re: [GTALUG] Messages are bouncing
by ac 27 Jul '18

27 Jul '18

I am so sorry, I made a stupid assumption. by simply stating "not really" I assumed that people would understand that this means that technically > > This seems to describe a problem where the recipient's mail service > > subscribes to a spam blocklist that is incorrectly blocking GTALUG. this is NOT the case... It is not GTALUG that is blocked... GTALUG is completely clean and in a clean IP range. mailman includes the relay IP number, in the headers, so the incoming email server checks all "Received: from " against whatever RBL dnsbl, etc. So, if the person/ip/sender, that 'sent' to the GTALUG mailing list, ip no is listed, THEN there are issues in receiving email...(by whatever recipient email server) so, sorry about that :( for the rest, I guess I could also elaborate a lot more if anyone is interested? On Fri, 27 Jul 2018 07:45:26 +0200 ac via talk <talk(a)gtalug.org> wrote: > > not really. > > the polar other side of your opinion is my opinion :) > > people supporting and paying money to resource whores who also are non > responsive to abuse complaints and whom also may host criminals and > other scumbags deserve to have their email refused :) > > the days of 'bullet proof' hosting are nearing the end as many mail > server admins are simply tired of constantly trying to do battle with > snowshoe and other rubbish. > > of course, again, best practise is not to 'drop' but to score email > incoming from abusive hosts and IP numbers as well as bad places on > the net, and at first mark them as spam, report that spam and then, > eventually, these resources will also end up in a permanent drop > dnsbl :) > > and; > > --Bob, who is experiencing such problems with the lists he manages. > > > does your list require people to opt in? or are people simply added > and then expected to unsubscribe? > > see, sometimes 'people' are not real people, they could be data in > stolen databases, they could be submitted by devious 3rd parties to > cause your list harm, there could be so many issues... > > If you are just adding email addresses to your list :) - then you will > find yourself experiencing issues if something goes wrong and you are > reported somewhere... > > On Fri, 27 Jul 2018 00:23:50 -0400 > Bob Jonkman via talk <talk(a)gtalug.org> wrote: > > > This seems to describe a problem where the recipient's mail service > > subscribes to a spam blocklist that is incorrectly blocking GTALUG. > > > > This is not GTALUG's problem; the recipients not receiving mail > > should complain to their mail provider to use a better blocklist. > > Or perhaps those recipients should switch to a different mail > > provider that doesn't use that blocklist. Selfhosting springs to > > mind... > > > > Alex shouldn't have to contact every poorly configured blocklist > > when recipient mail providers choose to use those poorly configured > > blocklists. Of course, when the recipients' mail provider doesn't > > give any indication to the recipient that their mail is being > > blocked, it's difficult for the recipient to know they're missing > > mail. And if mail from talk-owner(a)gtalug.org is also blocked, then > > it's impossible for the list owner to let the recipient know their > > mail is bouncing. > > > > --Bob, who is experiencing such problems with the lists he manages. > > > > > > > > On 2018-07-26 02:23 PM, Alex Volkov via talk wrote: > > > Oh, it's not the messages that list receives that get filtered > > > out, it's when mailman sends out list to the recipients, some who > > > have spamhaus and running on an IPv6 port get mailing list > > > messages filtered. > > > > > > We could disable IPv6 on our end, but it just feels wrong to me. > > > > > > Here's the error message I'm getting on my personal email server > > > > > > <subscriptions(a)flamy.ca>: host > > > mail.flamy.ca[2600:3c03:e000:173::1] said: 554 > > > 5.7.1 Service unavailable; Client host > > > [2600:3c03::f03c:91ff:fe50:ea0a] blocked using > > > sbl.spamhaus.org;https://www.spamhaus.org/sbl/query/SBLCSS > > > (in reply to RCPT TO command) > > > > > > > > > I believe the following hosts have similar settings to mine -- > > > > > > csclub.uwaterloo.ca > > > vex.net > > > > > > I believe there are 7 people including myself, that get routinely > > > affected by the issue. > > > > > > > > > > > > On 2018-07-26 03:06 AM, ac via talk wrote: > > >> Hi, > > >> > > >> There seems to be many people using non blocking RBL for DROP? > > >> > > >> Alex, Instead of using that specific spamhaus DNSBL for DROP you > > >> should rather use it for scoring? > > >> > > >> An example of a DROP RBL is chronic webiron.com and > > >> dnsbl.ascams.com these you can use for DROP? > > >> > > >> Will it not be better to add scoring to sa and then to add > > >> numeric values? > > >> > > >> hth > > >> > > >> Andre > > >> > > >> > > >> On Wed, 25 Jul 2018 12:06:23 -0400 > > >> Alex Volkov via talk <talk(a)gtalug.org> wrote: > > >> > > >>> We also have a web interface for mailman, so you can check if > > >>> you're messages are showing up there, since the default mailing > > >>> list settings is not to receive your own emails. > > >>> > > >>> https://gtalug.org/pipermail/talk/ > > >>> > > >>> > > >>> > > >>> On 2018-07-25 11:53 AM, James Knott via talk wrote: > > >>>> Let me know if you don't receive this message. ;-) > > >>>> > > >>>> > > >>>> I sent it to both the list and you directly, so you can see if > > >>>> it got through the list. > > >>>> > > >>>> On 07/25/2018 11:49 AM, Lennart Sorensen via talk wrote: > > >>>>> I don't think I have received any messages from the list in > > >>>>> about 2 weeks. The only thing I have gotten is a message > > >>>>> saying I have been removed due to bounces (strangely that one > > >>>>> didn't bounce). No idea why that would happen since other > > >>>>> things work fine, including lkml which is notorious for > > >>>>> hating bouncing emails. > > >>>>> > > >>>>> Anyone have any idea what could be going on? > > >>>>> > > >>>> --- > > >>>> Talk Mailing List > > >>>> talk(a)gtalug.org > > >>>> https://gtalug.org/mailman/listinfo/talk > > >>> > > >>> --- > > >>> Talk Mailing List > > >>> talk(a)gtalug.org > > >>> https://gtalug.org/mailman/listinfo/talk > > >> --- > > >> Talk Mailing List > > >> talk(a)gtalug.org > > >> https://gtalug.org/mailman/listinfo/talk > > > > > > > > > > > > > > > > > > --- > > > Talk Mailing List > > > talk(a)gtalug.org > > > https://gtalug.org/mailman/listinfo/talk > > > > > > > --- > Talk Mailing List > talk(a)gtalug.org > https://gtalug.org/mailman/listinfo/talk

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Re: [GTALUG] Messages are bouncing
by Alex Volkov 27 Jul '18

27 Jul '18

Oh, it's not the messages that list receives that get filtered out, it's when mailman sends out list to the recipients, some who have spamhaus and running on an IPv6 port get mailing list messages filtered. We could disable IPv6 on our end, but it just feels wrong to me. Here's the error message I'm getting on my personal email server <subscriptions(a)flamy.ca>: host mail.flamy.ca[2600:3c03:e000:173::1] said: 554 5.7.1 Service unavailable; Client host [2600:3c03::f03c:91ff:fe50:ea0a] blocked using sbl.spamhaus.org;https://www.spamhaus.org/sbl/query/SBLCSS (in reply to RCPT TO command) I believe the following hosts have similar settings to mine -- csclub.uwaterloo.ca vex.net I believe there are 7 people including myself, that get routinely affected by the issue. On 2018-07-26 03:06 AM, ac via talk wrote: > Hi, > > There seems to be many people using non blocking RBL for DROP? > > Alex, Instead of using that specific spamhaus DNSBL for DROP you should > rather use it for scoring? > > An example of a DROP RBL is chronic webiron.com and dnsbl.ascams.com > these you can use for DROP? > > Will it not be better to add scoring to sa and then to add numeric values? > > hth > > Andre > > > On Wed, 25 Jul 2018 12:06:23 -0400 > Alex Volkov via talk <talk(a)gtalug.org> wrote: > >> We also have a web interface for mailman, so you can check if you're >> messages are showing up there, since the default mailing list >> settings is not to receive your own emails. >> >> https://gtalug.org/pipermail/talk/ >> >> >> >> On 2018-07-25 11:53 AM, James Knott via talk wrote: >>> Let me know if you don't receive this message. ;-) >>> >>> >>> I sent it to both the list and you directly, so you can see if it >>> got through the list. >>> >>> On 07/25/2018 11:49 AM, Lennart Sorensen via talk wrote: >>>> I don't think I have received any messages from the list in about >>>> 2 weeks. The only thing I have gotten is a message saying I have >>>> been removed due to bounces (strangely that one didn't bounce). >>>> No idea why that would happen since other things work fine, >>>> including lkml which is notorious for hating bouncing emails. >>>> >>>> Anyone have any idea what could be going on? >>>> >>> --- >>> Talk Mailing List >>> talk(a)gtalug.org >>> https://gtalug.org/mailman/listinfo/talk >> >> --- >> Talk Mailing List >> talk(a)gtalug.org >> https://gtalug.org/mailman/listinfo/talk > --- > Talk Mailing List > talk(a)gtalug.org > https://gtalug.org/mailman/listinfo/talk

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Messages are bouncing
by lsorense＠csclub.uwaterloo.ca 26 Jul '18

26 Jul '18

I don't think I have received any messages from the list in about 2 weeks. The only thing I have gotten is a message saying I have been removed due to bounces (strangely that one didn't bounce). No idea why that would happen since other things work fine, including lkml which is notorious for hating bouncing emails. Anyone have any idea what could be going on? -- Len Sorensen

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GRUB's DSL and looping
by Giles Orr 25 Jul '18

25 Jul '18

There's probably a GRUB-specific mailing list or forum, but I thought I would try here first ... GRUB has a DSL ( https://en.wikipedia.org/wiki/Domain-specific_language ) that looks a lot like shell scripting. Most people never see it as it's used to generate the menus we use at boot-time and they see only the menus, but it can do some interesting things - particularly when you're dealing with multi-boot USB sticks. Here's a simple but slightly useful example: function cpuinfo { # only able to determine: 32/64 bit, and is it PAE echo "GRUB's ability to analyse processors is limited, we can only tell you:" if cpuid -p; then pae_assessment="PAE" else pae_assessment="NO PAE" fi if cpuid -l; then echo "64-bit processor, $pae_assessment" else echo "32-bit processor, $pae_assessment" fi } But it has some nasty limitations that are frustrating me: - no pipes - no command substitution - no file globbing That last in particular is really getting on my nerves. I want to source all the files in one folder, but I can't say 'for file in folder/* ; do' because the '*' is a literal character, no special meaning. Likewise, I can't say 'for file in `ls folder/` ; do' because there's no command substitution. I was wondering if anyone knows of a solution to this problem. Or even if you have ideas from long-gone old shells with similar limitations for which someone worked out a nasty work-around ... What I've been doing is 'for file in name1 name2 name3 ... ; do', but of course this only works if you remember to add new filenames to the list. I've googled quite a bit, but most people only modify GRUB through /etc/default/grub or, if they're really adventurous, through /etc/grub.d/40_custom or similar. What I'm looking for is (mostly) at a lower level than that, and examples are surprisingly hard to come by. And search results are occasionally polluted by GRUB4DOS results ... GRUB4DOS _does_ seem to support file globbing. All very confusing. Thanks. -- Giles https://www.gilesorr.com/ gilesorr(a)gmail.com

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Re: [GTALUG] Specific question about mailing list management
by Alvin Starr 25 Jul '18

25 Jul '18

It was over a year ago and I believe that it was a case of someone who could not follow the unsubscribe message at the bottom or did not read that far and pushed the message to one of the RBL providers. Another hint is to stick something in the mail message that will not get scrubbed by anonamizers if someone does post to an RBL. At least you can then find the offending client and remove them. Its a pain to have someone on your list that is pushing your messages to RBLs and not be able to remove them because the information you got from the RBL has all the usual tracking information removed. On 07/25/2018 09:48 AM, ac via talk wrote: > Hi Alvin, > > long time :) > > Have you been black listed by an RBL for a mailing list sending > verification emails? > > On Wed, 25 Jul 2018 09:26:04 -0400 > Alvin Starr via talk <talk(a)gtalug.org> wrote: > >> Another thing is to make sure you have a valid email address by >> sending an activation message. >> Lots of people will provide bogus addresses either deliberately or >> accidentally. >> You also need to monitor your outgoing email or track the bounce >> backs for email addresses that go away. >> >> One of the problems you will face is that conventional wisdom is that >> responding to an un-subscribe button is just a way that the spammers >> validate your email address. >> Also People will just tag the messages as spam causing you to get >> black-listed. >> >> Every few years I get blacklisted because I have someone running a >> small mail-list related to a Knitting e-commerce web site. >> The site admin is a good friend and I know they are very careful >> about the mail addresses in the list but bad emails still leak in. >> >> >> >> On 07/25/2018 02:06 AM, ac via talk wrote: >>> Hi Evan, >>> >>> The quick answer is that there is no agreement on best practise for >>> unsub messages, the amount of verification (and time span of) and a >>> number of other abuse related issues. >>> >>> Here is what I personally (wrongly or correctly) do: >>> Subscription (Opt in message / Confirm email message - 1 per day max >>> three days) >>> Unsubscribe - no message - just unsubscribe >>> >>> never send any email from noreply@ I am not Google or Microsoft >>> (and even the dentist around the corner is now doing that *sigh*) >>> >>> When subscriber does anything on a link (Web) - send a confirm your >>> request email >>> >>> hth >>> >>> Andre >>> >>> >>> On Wed, 25 Jul 2018 00:30:58 -0400 >>> Evan Leibovitch via talk <talk(a)gtalug.org> wrote: >>> >>>> Hi all. >>>> >>>> This question is asked of anyone who administers a mailing list >>>> about policies. I'm setting up a campaign-based mailing system >>>> using phplist (as opposed to a forum-type MLM such as Mailman) and >>>> I'm interested to know what policies or best practices you might >>>> have in place to address this specific question: >>>> >>>> When a list subscriber goes to a link to change their preferences >>>> or unsubscribe, from what email address does the confirmation (for >>>> changes) or "sorry to see you go" message (for unsubscriptions) >>>> originate. >>>> >>>> Does such administrative email come from: >>>> a) an identifiable member or the organization's staff? >>>> b) a postmaster-type alias? >>>> c) a do-not-reply address? >>>> >>>> Any feedback is appreciated. >>>> >>> --- >>> Talk Mailing List >>> talk(a)gtalug.org >>> https://gtalug.org/mailman/listinfo/talk > --- > Talk Mailing List > talk(a)gtalug.org > https://gtalug.org/mailman/listinfo/talk -- Alvin Starr || land: (905)513-7688 Netvel Inc. || Cell: (416)806-0133 alvin(a)netvel.net ||

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Re: [GTALUG] Specific question about mailing list management
by Alex Volkov 25 Jul '18

25 Jul '18

Hi Alvin, gtalug mailing list periodically gets blacklisted by smamhaus on our IPv6 address, then I have to go to their website and de-list us, which takes a minute or two, but lately this started happening every other week or so, and it's been pretty annoying. Alex. On 2018-07-25 09:48 AM, ac via talk wrote: > Hi Alvin, > > long time :) > > Have you been black listed by an RBL for a mailing list sending > verification emails? > > On Wed, 25 Jul 2018 09:26:04 -0400 > Alvin Starr via talk <talk(a)gtalug.org> wrote: > >> Another thing is to make sure you have a valid email address by >> sending an activation message. >> Lots of people will provide bogus addresses either deliberately or >> accidentally. >> You also need to monitor your outgoing email or track the bounce >> backs for email addresses that go away. >> >> One of the problems you will face is that conventional wisdom is that >> responding to an un-subscribe button is just a way that the spammers >> validate your email address. >> Also People will just tag the messages as spam causing you to get >> black-listed. >> >> Every few years I get blacklisted because I have someone running a >> small mail-list related to a Knitting e-commerce web site. >> The site admin is a good friend and I know they are very careful >> about the mail addresses in the list but bad emails still leak in. >> >> >> >> On 07/25/2018 02:06 AM, ac via talk wrote: >>> Hi Evan, >>> >>> The quick answer is that there is no agreement on best practise for >>> unsub messages, the amount of verification (and time span of) and a >>> number of other abuse related issues. >>> >>> Here is what I personally (wrongly or correctly) do: >>> Subscription (Opt in message / Confirm email message - 1 per day max >>> three days) >>> Unsubscribe - no message - just unsubscribe >>> >>> never send any email from noreply@ I am not Google or Microsoft >>> (and even the dentist around the corner is now doing that *sigh*) >>> >>> When subscriber does anything on a link (Web) - send a confirm your >>> request email >>> >>> hth >>> >>> Andre >>> >>> >>> On Wed, 25 Jul 2018 00:30:58 -0400 >>> Evan Leibovitch via talk <talk(a)gtalug.org> wrote: >>> >>>> Hi all. >>>> >>>> This question is asked of anyone who administers a mailing list >>>> about policies. I'm setting up a campaign-based mailing system >>>> using phplist (as opposed to a forum-type MLM such as Mailman) and >>>> I'm interested to know what policies or best practices you might >>>> have in place to address this specific question: >>>> >>>> When a list subscriber goes to a link to change their preferences >>>> or unsubscribe, from what email address does the confirmation (for >>>> changes) or "sorry to see you go" message (for unsubscriptions) >>>> originate. >>>> >>>> Does such administrative email come from: >>>> a) an identifiable member or the organization's staff? >>>> b) a postmaster-type alias? >>>> c) a do-not-reply address? >>>> >>>> Any feedback is appreciated. >>>> >>> --- >>> Talk Mailing List >>> talk(a)gtalug.org >>> https://gtalug.org/mailman/listinfo/talk > --- > Talk Mailing List > talk(a)gtalug.org > https://gtalug.org/mailman/listinfo/talk

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Specific question about mailing list management
by Evan Leibovitch 25 Jul '18

25 Jul '18

Hi all. This question is asked of anyone who administers a mailing list about policies. I'm setting up a campaign-based mailing system using phplist (as opposed to a forum-type MLM such as Mailman) and I'm interested to know what policies or best practices you might have in place to address this specific question: When a list subscriber goes to a link to change their preferences or unsubscribe, from what email address does the confirmation (for changes) or "sorry to see you go" message (for unsubscriptions) originate. Does such administrative email come from: a) an identifiable member or the organization's staff? b) a postmaster-type alias? c) a do-not-reply address? Any feedback is appreciated. -- Evan Leibovitch, Toronto Canada @evanleibovitch or @el56

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