May 2015 - Roundtable

email catchalls for spam tracking
by Trevor Cordes 13 May '15

13 May '15

As per discussion at the meeting tonight, here's all you need to have sendmail have a "catchall" email account so you can, on a whim, create unique email addresses for places you give your email address out to. #cat /etc/mail/virtusertable ... trevor(a)tecnopolis.ca trevor ... @tecnopolis.ca trevor So you must list all your normal local users manually as per the trevor@ line (not sure if there's an easier way to do this), and the last line says match any user I didn't already specify. You'll also need in your sendmail.mc: FEATURE(`virtusertable',`hash -o /etc/mail/virtusertable.db')dnl No other work required. No work required each time you give out a new address. Everything just goes into the normal inbox (trevor). Now when you start seeing 100 emails a month going into your spam inbox to hydrowhyareyouspammingme(a)tecnopolis.ca when you only ever gave that email out to hydro, you'll know something is fishy, and you know who to blame. As we said at the meeting, you almost certainly want to use with these ideas: greylisting bayesian filtering Using the above techniques I get less than 3 spams a week showing up in my inbox, even though I get at least 5k spams a week. I get roughly 3 non-spams a week "false positive" into my "low probability spam" box. I get maybe 3 non-spams a *year* into my "high probability spam" box. Unlike some people, my main goal isn't to never see spam, it's to never have a false positive dropped irretrievably by something outside (or even inside) of my control. Of course, my ~10 year strong .hammiedb spambayes "learned" ruleset file (binary, berkley db) is up to 326MB. A significant chunk of that has to page in on every email reception. I don't use them, but it might also help some people to use: spamassassin RBL's

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strangest request
by Trevor Cordes 06 May '15

06 May '15

>From O'Reilly's (geez that looks weird) support web site: http://support.oreilly.com/oreilly/topics/can-i-list-my-erotic-fiction-eboo… Says I: Huh?

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O'Reilly special deal
by Trevor Cordes 06 May '15

06 May '15

For those not on the O'Reilly mailing lists, I thought I'd pass this on: This is the best deal I've seen them do in months: 60% off ebooks/videos if you spend >$100. 50% otherwise. On all titles. They never go above 50% off, so this is a good deal. (Doesn't apply to print books.) Expires May 7, 2014 at 7AM CST http://post.oreilly.com/form/oreilly/viewhtml/9z1z7tocsqjqn45ju82c9k0sfe57h… If the URL doesn't work, their home page has a banner (as of right now).

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MUUG Meeting, May 12, 7:30pm -- GoAccess and AD Integration with SSSD
by Gilbert E. Detillieux 05 May '15

05 May '15

The Manitoba UNIX User Group (MUUG) will be holding its next monthly meeting on Tuesday, May 12. The meeting topic for this month is as follows: GoAccess and AD Integration with SSSD This month will be a double feature, with Wyatt Zacharias presenting the tool GoAccess for real-time Apache log analyzing, and report generation. Adam Thompson will then be presenting how to integrate an Ubuntu desktop with Windows Active Directory for login authentication using SSSD. This month's RTFM segment will feature units(1), a versatile unit conversion tool, presented by Gilbert Detillieux. The group holds its general meetings at 7:30pm on the second Tuesday of every month from September to June. (There are no meetings in July and August.) Meetings are open to the general public; you don't have to be a MUUG member to attend. ***************************************************************** Please note our *NEW* meeting location for this month: Room 1M28, Manitoba Hall, University of Winnipeg, entrance on Ellice Ave. between Spence St. and Balmoral St. Parking is available on the surrounding streets and in the lots on nearby streets. Look for signage once you're at the building, or ask a security guard. ***************************************************************** For more information about MUUG, and its monthly meetings, check out their Web server: http://www.muug.mb.ca/ Help us promote this month's meeting, by putting this poster up on your workplace bulletin board or other suitable public message board: http://www.muug.mb.ca/meetings/MUUGmeeting.pdf -- Gilbert E. Detillieux E-mail: <gedetil(a)muug.mb.ca> Manitoba UNIX User Group Web: http://www.muug.mb.ca/ PO Box 130 St-Boniface Phone: (204)474-8161 Winnipeg MB CANADA R2H 3B4 Fax: (204)474-7609

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*reading* a file causes reboot
by Trevor Cordes 05 May '15

05 May '15

This was a lovely "bug" to run into during a server migration tonight. as root: grep -r / foobar cause a new system to crash/reboot. Did it again and it did it exactly at the same place. The last line was about not being able to read (or some similar error) /dev/watchdog Rackspace thought it was a bug too, and quite odd, then they looked around and decided this is "normal" when watchdogs are turned on. Huh? I haven't bz-checked this yet, but this smells funny to me. A read of a file should never *trigger* an action, right? It's like a /sys file: you echo > to them to get it to do something, never *read*. Any thoughts? If I don't find a bz about it, I'm definitely going to make one. (RHEL6) RS claims the only "fix" is to disable watchdog or make sure not to grep -r /. I know grep -r / is really cheesy and lame-o and wasteful as there's not going to be something in /dev I'll need (and reading /dem/kmem is really cheesy) but sometimes I really need to find all occurences of something fast with the least hassle possible (not going into / and ls'ing and deciding what to include/exclude which is different on many systems). My point is, grep -r / has never given me trouble in the past 20 years, but then again I usually don't have a watchdog.

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Solaris/UNIX root-like file access
by Kevin McGregor 04 May '15

04 May '15

In Solaris 11, "root" by default is a role, not an account you can log into. I'd like to create an account with generally fewer privileges than root -- in fact no privileges at all -- *except* I want to make sure it can read all regular files and directories in order to do a backup. Is that possible/feasible? In Windows, there's a group called "Backup Operator" which does something like this. Is the only alternative in Solaris to make the account a member of the "root" group? I don't care about e.g. device files and the like. I just want the account to be able to back up regular ZFS user-type file systems. Feel free to ask me questions to clarify this. I'm probably not explaining it well. Kevin

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Looking for support for DRBD/XenServer setup
by Gerald Brandt 02 May '15

02 May '15

Hi, I have a client I've been supporting for a number of years. I set up a DRBD system serving iSCSI to 2 Citrix XenServer 5.6 systems. I've recently shut down my business, and my client needs someone to look after his servers. They are very low maintenance. If there is anyone with DRBD (on Ubuntu) and XenServer experience that is looking at picking up a new client, please contact me. Gerald

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