- Roundtable - muug.ca

math puzzle with U of M solution
by Trevor Cordes 09 Dec '15

09 Dec '15

As discussed at the meeting last night. Here's a fun math problem where the solution was submitted by a U of M student to Mike 20 years ago. Not often Winnipeg gets mentioned in international press! And the solution is even more nuts than I said last night: you also have to use imaginary numbers! Linux Mag makes you pay $2.95 paypal to read the whole article (you can read the first bit free). Worth it if you're interested. I think if you wait a few months they release the article for free. http://www.linux-magazine.com/Issues/2015/179/Perl-Math-Problems

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FS: power supply lots
by Trevor Cordes 09 Dec '15

09 Dec '15

Forsale: 1999-2004 era used computer power supply lots. Seeing if anyone might have any interest, for a project, spares, parts, etc. They are older style (pre-24pin era). These are all standard form factor (PS2, fits all standard size MATX and ATX cases), 20-pin ATX connector (not the 24-pin required today). All PS's are used, most are in working condition, a few might have bad caps or dying fans (details are available). If anyone is interested I can run more thorough tests, I have a testing tool. Price would be quite inexpensive per unit, open to reasonable offers. Will separate if desired. LOT 1 (the newest): qty 7; with auxillary 4pin (2x2) square connector ("P4" connector for extra CPU power introduced in the P4 era). LOT 2: qty 20 or so; without aux 4pin; from P2/P3 era. (Also have AT power supplies if everyone ever needs any.) Email me separately, thanks!

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setting "word-chars" in gnome-terminal
by Trevor Cordes 02 Dec '15

02 Dec '15

As per a comment I made maybe a year ago at a general meeting during roundtable regarding gnome-terminal removing the ability to set your own set of "word stop characters". This annoyed me (as an admin and programmer) to no end because all of a sudden I was forced to accept that double-clicking a word would also select : and #, and some other crazy characters that aren't "word chars" to me. They finally fixed this bug earlier in the year. Fedora 22 has the fix (vte 0.28 and gnome-terminal 3.16 and newer in any OS). However, the fix does not provide a GUI way to change the chars. Furthermore, the new method is pretty confusing. I haven't seen a good explanation/documentation yet on the net, in the bugzillas or elsewhere. Here's mine: First, get your gnome-terminal (g-t) "profile id". Right-click in your g-t -> Profiles -> Profile Preferences (make sure your desired / usual profile is selected). The UUID-ish looking thing in the General tab after "Profile ID" is what you need. You can select it, and paste it below (or retype it). For ease of manipulation, we'll put that profile-id into a shell var: csh/tcsh: set z=b1dcc9dd-5262-4d8d-a863-c897e6d979b9 sh/bash/ksh: z=b1dcc9dd-5262-4d8d-a863-c897e6d979b9 Note, that string might be the same for you, that's my default profile id, and it seems to pop up in other people's comments so it may be some kind of hardcoded value for the default profile. See what your values are set to: dconf read /org/gnome/terminal/legacy/profiles:/:$z/word-char-exceptions dconf read /org/gnome/terminal/legacy/profiles:/:$z/word-chars Your word-char-exceptions may be blank, and your word-chars may be set to something if you are on a box you've upgraded from old versions. Anyhow, you'll notice word-chars is being ignored. It's obsolete. Hose it (or just ignore it, but it confused me to no end until I confirmed with a dev it was being ignored): dconf reset /org/gnome/terminal/legacy/profiles:/:$z/word-chars Now we set the word-char-exceptions we want. Here's the confusing part: this value is what we WILL consider a word-char, and so chars you put in here will be selected when you double-click. Even worse, A-Za-z0-9 seem hardcoded in there, so you don't need to specify them. The nomenclature stinks because to me what you are setting aren't "exceptions", they are actual word-chars. Perhaps it should have been named word-char-additions. Here's how you set it: dconf write /org/gnome/terminal/legacy/profiles:/:$z/word-char-exceptions '@ms "-/(a)_&.?"' If you had word-chars previously set and liked it, just remove A-Za-z0-9 from that list and put the remainder chars in the word-char-exceptions list. You must move the dash to the front, right after the double-quote, like in a regex character class. You can specify ranges (in ascii) of chars using the dash elsewhere. I have no idea what the @ms and extra quoting is for, but the dev put that in his example and it works. I'm not sure how you'll get a ' or " in the list, but I'm sure it's possible (single quote should be easy but who knows how dconf wants the double escaped). As a programmer, making either quote a word char is insanity so I leave that as an exercise for the reader. The write to dconf takes effect immediately in your running g-t's, no need to restart anything. I (strongly) assume this writes to a persistent store somewhere so you don't have to do it on each boot. The devs say they'll put the GUI option back in the preferences dialog sometime in the future. That'll be much nicer! Why it was ever removed is beyond me. Now, onto another bz as to why the --title option in g-t was removed... Big thanks to Egmont Koblinger for being (one of) the driving force behind getting this option put back in.

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ECC - 8 chips?
by Trevor Cordes 02 Dec '15

02 Dec '15

I'm doing some ECC RAM shopping on ebay (as per prev postings). I came across something weird. There's a stick showing up in various places that claims to be ECC but all pics (and the physical unit, I've confirmed) have only 8 (or 16) DRAM chips, not 9 or 18. Does this make any sense to anybody? Is this possible?? The stick is Kingston KTH-XW4400E6/2G http://www.walmart.com/ip/Kingston-KTH-XW4400E6-2G-2GB-ECC-DDR2-800-240-pin… http://www.ebay.ca/itm/221949985186? http://www.newegg.ca/Product/Product.aspx?Item=N82E16820134842 specifically says in "overview" it has "Error Checking and Correcting Technology" Kingston has discontinued this part and it's hard to even find on the site anymore, but here's: http://www.ec.kingston.com/ecom/hyperx_us/partsinfo.asp?root=&ktcpartno=KTH… says x72 ECC The equiv HP #'s they provide all show up on the net as 9 chip, so this Kingston stick should be ecc. ??? WTF?

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MUUG Meeting, Dec 8, 7:30pm -- Zenworks: The Other CM
by Gilbert E. Detillieux 01 Dec '15

01 Dec '15

The Manitoba UNIX User Group (MUUG) will be holding its next monthly meeting on Tuesday, December 8. The meeting topic for this month is as follows: Zenworks: The Other CM Heard about ZENworks but never really seen it? In this month's presentation, Katherine Scrupa will be discussing her trials and tribulations with Novell's Configuration and Systems Management suite. Learn how to control the behaviour of software bundles, which bugs and gotchas to watch out for, and discover new version features in the 11.3 version of ZCM. Round-table, Mingling and Munchies As 2015 draws to a close, MUUG is going to continue our recent tradition of turning the December meeting into more of a social event. We will have the usual round-table session, followed by a presentation, and then have some time for mingling, eating, and drinking. This will be a pot-luck snack event. Cookies and pop will be provided by MUUG, but members are encouraged to bring their own finger food to sample and share. Feel free to bring your own drink as well if you want something particular - just remember that we don't have a liquor license! Winnipeg Harvest Food Drive Also as in previous years, we are combining our pot luck with a food drive for Winnipeg Harvest. This month, any member who brings at least 1 item for Winnipeg Harvest to the December meeting will be given an entry into the door prize draw! Winnipeg Harvest has information about what they're looking for on their website: http://winnipegharvest.org/donate-food/ 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 -- Manitoba UNIX User Group E-mail: <gedetil(a)muug.mb.ca> c/o Gilbert E. Detillieux Web: http://www.muug.mb.ca/ University of Manitoba Phone: (204)474-8161 Winnipeg MB CANADA R3T 2N2 Fax: (204)474-7609

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"un-RAIDing" a Linux P2V
by Wyatt Zacharias 01 Dec '15

01 Dec '15

So I'm attempting to virtualize one of our Redhat 5 boxes using VMWare's P2V functionality, and it's copied all the data into the VM without any trouble, but now I can't seem to get the virtual machine to boot because it's not detecting the virtualized partitions correctly. The physical system was using LVM on top of dm-raid to local disks. When VMWare virtualized the disks, it created a single disk, and copied the LVM layout onto it, so I think what's happening is on boot, the system is looking for the RAID disks and can't find them. When I try to boot it, it says that it can't find the logical volumes and goes into a kernel panic. I've booted with a rescue disk, and when I run a pvscan on the new virtual disk, all the volumes are there and can be mounted, so the problem must be that the system isn't looking for the volumes in the right place. I've tried changing the root device to /dev/sda in the device.map comfig file, and I rebuilt the initrd file with both the --force-lvm-probe and --omit-raid-modules and it still loads dm-raid on boot. So how do I get the system to completely forget about RAID, and boot off the new virtual disk? Is there a RAID config somewhere that I'm missing? -- Wyatt Zacharias

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O'Reilly 60% off is back
by Trevor Cordes 28 Nov '15

28 Nov '15

It's back, O'Reilly's periodic (twice yearly?) 60% off sale on *all* e-books and vids (but not print books). You have to spend $100 (US$) to get the 60%, otherwise it's only 50%. Based on past experience they never go cheaper than 60% off. I'm still waiting for blow-out deals on print, but they never come... http://shop.oreilly.com/category/deals/cyber-monday.do Ends Dec 1, 5am PT.

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Amazon price jacking
by Trevor Cordes 19 Nov '15

19 Nov '15

Thought I'd drop the group a quick observation regarding Amazon. I'm always on the eye out for O'Reilly books and keep an eye on Amazon pricing (both new and used) for the books in my want-list. A strange thing just happened I haven't noticed before. In the last .5 to 1.5 weeks Amazon.ca jacked up the "new, sold by Amazon" prices on nearly all the O'Reilly titles I am watching (some recent titles, some ancient) about 20%! In that time the CA$ went down by at most 2%. My guess is it's one of three things: 1. Jacking prices up for Christmas because they can get away with it. 2. Jacking prices up before Black Friday/Monday(whatever) so they can claim their new prices are "sales" when in fact they are the prices from 2 weeks ago! 3. They held back the CA$ pressure as long as they could then finally broke and jacked them up 20% in one go. #3 seems unlikely because their prices fluctuate nearly every day, probably on the exchange rate. Indigo prices seem to have followed Amazon, so it looks like this is a common book store tactic. If you don't need a book for a present, might want to wait until January to buy as prices should drop by 20% again. Even more if the CA$ ever recovers.

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WTB: DDR2 ECC UNB 2GB
by Trevor Cordes 18 Nov '15

18 Nov '15

Hi! If anyone happens to have any (relatively) obsolete DDR2 ECC modules kicking around, I'd like to buy 2 or 4 sticks. I need unbuffered, unregistered, ECC, DDR2, 667 or 800 MHz, normal mobo size (not sodimm). Note, if you don't know if your RAM is ECC, it probably isn't (ECC is "kind of server"). Note also that buffered/reg'd is useless to me too. Email me privately. Thanks!

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metadata *is* in the inode
by Trevor Cordes 16 Nov '15

16 Nov '15

At the meeting last week we were discussing inodes and metadata, and where metadata is actually stored. I double-checked what I was saying, just to make sure, and it turns out I was correct: many modern fs's (like ext4) store some metadata in the inode. This is because ext4 has a 256 byte inode by default but only needs about half of that to store "normal" inode data. Thus, "the remaining space after the ext4_inode structure is normally used to hold extended attributes". That would include capabilities (along with selinux stuff, etc), I would assume. Of course, if your metadata is over about 100 bytes then the fs will need to allocate other blocks for the metadata. I'm sure there's a way to test all this with just ls, df and setcap or selinux. Further, looks like there's a patch called "Inline data" (doesn't seem to be in my kernel, perhaps not mature yet) that allows *data* to be put in the empty space. That would allow tiny (100 byte) files (or even directories with few files?) to use no blocks at all! They'd also load super fast. I swear that I've seen that behavior on my systems, but I'm not sure which, perhaps my XFS fs. Perhaps if your fs is full of tons of tiny files you could gain huge advantage by setting your inode size even higher (at fs creation time only)! source: https://lwn.net/Articles/469805/

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