- Roundtable - muug.ca

*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 03 May '15

03 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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Manitoba Hydro email database hacked (or sold)
by Bradford C. Vokey 30 Apr '15

30 Apr '15

Trevor Cordes (and myself) use vendor specific email addresses when we sign up for services (it's easy when you control your own domain). Manitoba Hydro sends me email to 'manitobahydro(a)yourowndomain.com' Shaw send me email to 'shaw(a)yourowndomain.com' ...etc... For several months now, both Trevor and myself have noticed spammers using our Manitoba Hydro vendor specific email addresses. So how (and when) did Manitoba Hydro get their email accounts list hacked? If so, what else got hacked? Our per-authorized Debit information?!? If not, then did they actually sell their email accounts lists to spam lists? I can see spammers sending generic *names* to various domains (ie. trevor(a)yourowndomain.com or brad(a)yourowndomain.com) but I can not see spammers sending 'manitobahydro' to various domains without some per-initializing from somewhere. Just my rant for the week/day/hour... ...P.S. If anyone wants to meet some desperate Russian chick feel free to believe in the spam... === Bradford C. Vokey Treasurer Manitoba Unix User Group === -------- Forwarded Message -------- Subject: Allow me to introduce ... to you. Date: Sat, 25 Apr 2015 19:14:40 +0300 From: mstanton(a)packeteer.com To: manitobahydro(a)fsi.ca Greetings! How's it going? I found out your email in the agency of acquaintances. They also told me you are not married and you wish to meet a sweetheart. I decided to try to email you and get to know you better. I will tell you some information about myself. I am 28 years old. No kids. I would like to meet a sane and responsible person. I do not need to play any online games, I would like to have serious relationship only. If you are interested to know more about my life, please tell me and I will be happy to tell you more info about myself and I will also send you photos! My private email: lina-fo(a)rambler.ru Elena

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Shaw email - new woes
by Trevor Cordes 26 Apr '15

26 Apr '15

Great, Shaw is playing with email things again :-( All of a sudden all emails from my box (on a shaw cable modem) outgoing (via Shaw's recommended smarthost) were being blocked by Shaw. They blocked me from 1am to 4:30pm. I've been using this setup for 10+ years and never had a problem. They must have switched to a new email outsource service or something. Even funnier, what triggered it seems to be this: I'm trying to help my customer with Spam problems and the RT ticket he made (and hence email subject) had the word "Spam" and Shaw barfed it back and started the blocking without warning: ========================= Date: Fri, 24 Apr 2015 01:07:55 -0500 From: Mail Delivery Subsystem <MAILER-DAEMON(a)tecnopolis.ca> Subject: Returned mail: see transcript for details The original message was received at Fri, 24 Apr 2015 01:07:54 -0500 from localhost.localdomain [127.0.0.1] ----- The following addresses had permanent fatal errors ----- <customer(a)mycustomer.com> (reason: 552 5.2.0 lWmIYQYgD7S0qlWmJYSEv0 spam rejected) ----- Transcript of session follows ----- ... while talking to shawmail.wp.shawcable.net: >>> DATA <<< 552 5.2.0 lWmIYQYgD7S0qlWmJYSEv0 spam rejected 554 5.0.0 Service unavailable [...] Subject: [Tecnopolis #2173] Spam Possible ========================= Hahaha. Pathetic. So any email that wants to talk about spam and has that word in the subject is blocked? What if I want to talk about viagra or rolex, is that blocked too? All subsequent emails for the whole day got a bounce: ========================= The original message was received at Fri, 24 Apr 2015 02:54:59 -0500 from localhost.localdomain [127.0.0.1] ----- The following addresses had permanent fatal errors ----- <customer(a)mycustomer.com> (reason: 554 mo23.dcs.int.inet shaw.ca ESMTP server not available) ----- Transcript of session follows ----- ... while talking to shawmail.wp.shawcable.net: <<< 554 mo23.dcs.int.inet shaw.ca ESMTP server not available 554 5.0.0 Service unavailable ========================= WTF is mo23.dcs.int.inet? Looks new to me. Anyhow, after a call to a clueless tech rep telling me I'm unsupported because I run sendmail *simply as an outgoing mail MTA pointing directly to their smart host* and an email to their (hopefully) more advanced techs, I got nowhere until it magically fixed itself at 4:30. I probably hit their BL timeout or something. I dare anyone on the Shaw network using normal SMTP outgoing to send an email with the subject of "sp*m" (I dare not spell it out in full, he who can't be named and all that). Let me know if they block you for a day and whether you get anywhere with tech support. Shame on Shaw. Almost getting as bad as MTS. Wait a minute, no one can get *that* bad (MS Live mail anyone?). :-)

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Re: [RndTbl] Shaw email - new woes
by Bradford C. Vokey 26 Apr '15

26 Apr '15

I have many emails sent to me (as a reply) with *** SPAM *** in the subject line (because the emails we send out sometimes get triggered as SPAM by some school divisions and they are just replying). I have then replied (sometimes forgetting to removing the "*** SPAM ***" in the subject line) and it hasn't been a problem so far. The last email we sent with SPAM in the subject line was 2015-01-09. 1) We do have a static IP so that might be different? 2) We also have a Shaw business account (as opposed to home/personal)? 3) Maybe this is just new as of this week/month? 4) Maybe your client was legitimately sending SPAM and Shaw just blocked them until it stopped? Bradford C. Vokey - Director ============================== Fortress Software Incorporated ============================== 390 Provencher Blvd Unit F Winnipeg, Manitoba, Canada R2H 0H1 ----------------------------------------------- Phone: (204) 231-3969 or 1-800-665-0396 FAX: 1-800-513-9356 ----------------------------------------------- mailto:fortress2014@matchomatics.com matchomatics.com spiritoos.com On 2015-04-25 12:00 PM, roundtable-request(a)muug.mb.ca wrote: > Even funnier, what triggered it seems to be this: I'm trying to help > my customer with Spam problems and the RT ticket he made (and hence > email subject) had the word "Spam" and Shaw barfed it back and started > the blocking without warning:

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expert RAID question
by Trevor Cordes 25 Apr '15

25 Apr '15

I'm reading a book talking about RAID 5. For writes (only), it says: In the case when: "The write changes exactly one disk. The parity context doesn't need to be recovered, since we can compute it just as if the disk had failed. The write involves one write and one parity write. Performance is about 50% of a single disk." ("Parity context" in this book means the contents of that entire stripe; so saying it doesn't need to be recovered means that you don't need to read the other n-2 disks (+1 parity disk) that hold that stripe.) I'm trying to figure how you "can compute it just as if the disk had failed". This makes no sense to me. I don't see how you could possibly get away with only 2 writes and no reads when changing just a single disk's block in a RAID 5 array. What am I missing?? (This book does have errors, and I am wondering if this is one of them.)

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Distributed/replicated home directories?
by Adam Thompson 21 Apr '15

21 Apr '15

I'm looking for the sweet spot between: - NFS-mounted home directories, which allow easy central management and are portable across every workstation, but are (typically, and in my case) IOPS-limited, and - local home directories, which are tied to the workstation but offer great performance At this point I'm seriously considering things like GlusterFS, Lustre, CephFS, etc., because the NFS performance sucks so badly for doing things like a) running Chrome, and b) running VirtualBox. Looking for ideas... [image: Avant logo] *Adam Thompson* Senior Systems Administrator *voice:* 204.789.9596 x24 | *email:* athompson(a)avant.ca | *web:* avant.ca

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Re: [RndTbl] [Board] Units(1) for RTFM?
by Gilbert E. Detillieux 21 Apr '15

21 Apr '15

Here's a fun one to try... units -v lightyear "light year" Confused? Try "units -v" on each of the terms individually, and the results might be enlightening, albeit a bit time-consuming. (Sorry, I couldn't resist.) Astronomy geeks might want to browse the units.dat file (RTFM), to find out just how many ways you can define a year! :P And speaking of RTFM, +1 for units as a future RTFM topic. Gilbert On 21/04/2015 10:38 AM, Michael Doob wrote: > So you can also compute how many feet light travels in a nanosecond > (Try it; you can remember the answer with less than 2% error). RIP Grace Hopper! (Look it up if you're too young to remember.) > Cheers, > Michael > > > On 15-04-21 09:22 AM, Sean Walberg wrote: >> My favourite has always been: >> >> You have: 1 nanoacres >> You want: mm2 >> * 4.0468564 >> / 0.24710538 >> >> On Tue, Apr 21, 2015 at 8:41 AM, Bradford C. Vokey <brad(a)fsi.ca >> <mailto:brad@fsi.ca>> wrote: >> >> And once again, I learn something new from the master Adam. >> >> I'z immediately "yum install units" >> >> I think units(1) might make a good RTFM? Especially going over >> some of it's esoteric units (i.e. millilightseconds? really?). >> >> Or have we done units and I just can't remember? >> >> === >> Bradford C. Vokey >> >> Treasurer >> Manitoba Unix User Group >> === >> >> On 2015-04-21 6:53 AM, roundtable-request(a)muug.mb.ca >> <mailto:roundtable-request@muug.mb.ca> wrote: >>> Feeling slightly giddy, I typed into my shell: >>> >>> $ units >>> 1311 units, 63 prefixes >>> >>> You have: 3 millilightseconds >>> You want: miles >>> * 558.84719 >>> / 0.0017893979 >>> >>> "500 miles, or a little bit more." -- 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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Units(1) for RTFM?
by Bradford C. Vokey 21 Apr '15

21 Apr '15

And once again, I learn something new from the master Adam. I'z immediately "yum install units" I think units(1) might make a good RTFM? Especially going over some of it's esoteric units (i.e. millilightseconds? really?). Or have we done units and I just can't remember? === Bradford C. Vokey Treasurer Manitoba Unix User Group === On 2015-04-21 6:53 AM, roundtable-request(a)muug.mb.ca wrote: > Feeling slightly giddy, I typed into my shell: > > $ units > 1311 units, 63 prefixes > > You have: 3 millilightseconds > You want: miles > * 558.84719 > / 0.0017893979 > > "500 miles, or a little bit more."

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