July 2011 - Roundtable

Winnipeg Harvest donations from December meeting - thank you!
by athompso＠muug.mb.ca 04 Apr '12

04 Apr '12

Thanks to the generosity of our members, we were able to donate three large boxes’ worth of non-perishable food items to Winnipeg Harvest in December 2010. The text of the thank-you letter we just received (see attached) is as follows: January 5, 2011 Manitoba UNIX User Group Attn: Adam Thompson Dear Friends of Harvest, We here at Winnipeg Harvest want to thank the Manitoba UNIX User Group for your support of helping those less fortunate in our community. Over the last few months 743 pounds of food was donated to the food bank. Your donations will go into hampers that will help Winnipeg Harvest feed more than 58,000 people each month, half of those being children. On behalf of the entire team at Winnipeg Harvest, thank you for helping us fight hunger and feed hope in Manitoba. We look forward to working with you again in the future. If I can ever be of assistance, please don’t hesitate to contact me by phone at 982-3670 or by email at tori(a)winnipegharvest.org. Yours truly, Tori Webber Development Associate Winnipeg Harvest Inc. So, thanks again. See you all in another six (6) days, at our next meeting on January 11th, 2011. -Adam Thompson athompso(a)muug.mb.ca

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isostick - the optical drive in a usb stick
by Adam Thompson 30 Jul '11

30 Jul '11

http://www.kickstarter.com/projects/elegantinvention/isostick-the-optical-d… The concept is definitely viable, since Sandisk did something very similar in their Cruzer line of products, except you can’t update the contents of the fake CD-ROM drive yourself on a Cruzer. I’m buying one! -Adam Thompson <mailto:athompso@athompso.net> athompso(a)athompso.net (204) 291-7950 - direct (204) 489-6515 - fax

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Fwd: [WARNING] Index corruption and crashes in Apache Lucene Core / Apache Solr with Java 7
by Adam Thompson 28 Jul '11

28 Jul '11

FYI - this will affect an awful lot of Java apps. -Adam -------- Original Message -------- Subject: [WARNING] Index corruption and crashes in Apache Lucene Core / Apache Solr with Java 7 From: Uwe Schindler <uschindler(a)apache.org> To: announce(a)apache.org, <general(a)lucene.apache.org>, <java-user(a)lucene.apache.org>, <solr-user(a)lucene.apache.org> CC: Hello Apache Lucene & Apache Solr users, Hello users of other Java-based Apache projects, Oracle released Java 7 today. Unfortunately it contains hotspot compiler optimizations, which miscompile some loops. This can affect code of several Apache projects. Sometimes JVMs only crash, but in several cases, results calculated can be incorrect, leading to bugs in applications (see Hotspot bugs 7070134 [1], 7044738 [2], 7068051 [3]). Apache Lucene Core and Apache Solr are two Apache projects, which are affected by these bugs, namely all versions released until today. Solr users with the default configuration will have Java crashing with SIGSEGV as soon as they start to index documents, as one affected part is the well-known Porter stemmer (see LUCENE-3335 [4]). Other loops in Lucene may be miscompiled, too, leading to index corruption (especially on Lucene trunk with pulsing codec; other loops may be affected, too - LUCENE-3346 [5]). These problems were detected only 5 days before the official Java 7 release, so Oracle had no time to fix those bugs, affecting also many more applications. In response to our questions, they proposed to include the fixes into service release u2 (eventually into service release u1, see [6]). This means you cannot use Apache Lucene/Solr with Java 7 releases before Update 2! If you do, please don't open bug reports, it is not the committers' fault! At least disable loop optimizations using the -XX:-UseLoopPredicate JVM option to not risk index corruptions. Please note: Also Java 6 users are affected, if they use one of those JVM options, which are not enabled by default: -XX:+OptimizeStringConcat or -XX:+AggressiveOpts It is strongly recommended not to use any hotspot optimization switches in any Java version without extensive testing! In case you upgrade to Java 7, remember that you may have to reindex, as the unicode version shipped with Java 7 changed and tokenization behaves differently (e.g. lowercasing). For more information, read JRE_VERSION_MIGRATION.txt in your distribution package! On behalf of the Lucene project, Uwe [1] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134 [2] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7044738 [3] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7068051 [4] https://issues.apache.org/jira/browse/LUCENE-3335 [5] https://issues.apache.org/jira/browse/LUCENE-3346 [6] http://s.apache.org/StQ ----- Uwe Schindler uschindler(a)apache.org Apache Lucene PMC Member / Committer Bremen, Germany http://lucene.apache.org/ --------------------------------------------------------------------- To unsubscribe, e-mail: announce-unsubscribe(a)apache.org For additional commands, e-mail: announce-help(a)apache.org

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rsync update in RHEL 5 is broken
by Gilles Detillieux 27 Jul '11

27 Jul '11

Just a heads-up for anyone running RHEL 5 or a clone (CentOS or SL). The latest update to rsync, version 3.0.6-4.el5, may break any backup scripts you have that rely on the remotehost:remotedir notation to access systems via ssh. Red Hat's package for this includes a patch that breaks this unless you prepend the username@ part before the host name. I had that nasty surprise this morning after yesterday's update. Your options are to alter your backup scripts to use the user@host:dir notation, or to exclude this update until they release a fixed version. If you've already installed the update, "yum downgrade rsync" seemed to do the trick to revert to the 2.6.8-3.1 version on my SL 5.6 systems. -- Gilles R. Detillieux E-mail: <grdetil(a)scrc.umanitoba.ca> Spinal Cord Research Centre WWW: http://www.scrc.umanitoba.ca/ Dept. Physiology, U. of Manitoba Winnipeg, MB R3E 0J9 (Canada)

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HP MicroServer
by Sean Cody 15 Jul '11

15 Jul '11

Anyone have any experience with these? Kinda seem too good to be true. Looking for a small appliance (low power, no/low hassle) like replacement for my Dlink DNS-323. The 323 is great but I need more disk and better performance (currently 12-15MB/s on Gig-E,jumbo frames). An HP MicroServer with 4x2TB in 2xRAID-1 (and booting FreeNAS from a decent USB stick) seems like it might fit the bill. Comments, recommendations? I'll still use the 323 (i have lots of junk on it and the UPnP/DNLA, iTunes server etc work great) but some bulkier storage to hold ISOs of all my DVDs are why I'm heading down this road. -- Sean (mobile) P.S. The Patriot Box and the WD-Live HD will play ISOs of DVDs _WITH_ menus.

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Partitioning in Linux
by Kevin McGregor 11 Jul '11

11 Jul '11

Well, not really partitioning. I know how to do that. At work today, the question of how to set up some Linux servers arose. To put it in some kind of context, when I install Ubuntu Linux (server), by default it creates a small /boot partition, the creates a LVM partition with a / ext4 partition and a swap partition inside of that. Is that optimal? Recommended? Some would say that /home, /tmp, /var and others should reside in separate partitions/filesystems. Discuss. :-) Thanks for any input! Kevin

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IPv6 only diet followed by presentation?
by Mark Jenkins 11 Jul '11

11 Jul '11

I read the recent discussions here on IPv6 and the interest in a presentation. I've been playing with IPv6 for a few years now, recently participated as both an end user and service provider on IPv6 day (June 8). Have recently been thinking about putting myself on an IPv6 only diet at both work and home to try and break my addiction to news and articles on the web so I can get some real work done. (most of my favourite time killer web sites don't have ipv6 enabled; the AAAA records are not even available in the name server my tunnel broker uses which does successfully query records unavailable to most like google.ca AAAA) After the Wikipedia binge I went on today I'm thinking I might as well bite the bullet, follow through on this idea, and make a MUUG presentation out of it. Consider that my formal offer to do it. (subsequent details I'll take off list direct with board folks) Like all diets, I know I'm going to cheat -- but hopefully only for work purposes and by suffering the inconvenience of tunneling and proxies to reach ipv4 on an as needed basis. (shouldn't be too much, too often.. so I think...). What I'm implying by IPv6 only is that I'd like to go without a v4 address assigned to my personal machines at all -- it will be my routers at home and work that will be dual stack -- allowing me to be single stack on my actual machines without screwing things up for everyone else that I share those routers with. Could present in September, but with some fairly busy stuff going on September/October I'd prefer November. Presentation outline: 1. Basic address, subnet, and routing theory 2. Manual command line configuration in zee penguin land -- address auto discovery and static config 3. Reflections on my IPv6 only diet over the last few months 4. My theory and advocacy on how a transition could come about without putting everyone on dual stack first. 5. The "joy" of writing ipv6 reverse DNS entries and fun with the $ORIGIN keyword in BIND (time permitting) 6. route advertisement daemon (time permitting Topics I'm not going to cover: * DHCPv6 * setting up any garden variety of tunneling I am going to bring a wireless access point (disabled as a router), hook it up to my laptop, run a route advertisement daemon and let folks use address auto discovery to pull real ipv6 addresses from me and be able to access the ipv6 internet through me for the evening. This is the easiest "try it" you could possibly get -- beats manual tunnel set up. Thinking of giving priority in the presentation to questions asked over a jabber daemon that I'll restrict to ipv6 only as an additional incentive for folks to try it. (also fun for anyone in a merry prankster mood to put things on my screen....) Mark

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Karanbir Singh: Release for CentOS-6.0 i386 and x86_64
by Adam Thompson 11 Jul '11

11 Jul '11

http://www.karan.org/blog/334@http://www.karan.org/blog/ ...for those of you who haven't seen this already. -Adam

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RHEL et al. - how to break mkinitrd(8)
by Adam Thompson 08 Jul '11

08 Jul '11

CentOS 5.6 system. Running happily. Applied kernel update, reboot, PANIC - unable to mount root filesystem. (Along with other various weird error messages.) Spent a lot of time deconstructing initrd(4)s. Final root cause of the problem: in fstab(5), I had manually added a swap partition. "mount -a" didn't care, but mkinitrd sure did: I had fstab like this: /dev/sda1 / ext3 defaults 1 1 /dev/sdb1 / swap defaults 0 0 Mkinitrd(8) was tripping over the "/" in field #2 of the swap record, and generating a non-functional /init script in the initrd. Changing the second line to read "/dev/sdb1 swap swap defaults 0 0" fixed the problem. Aside from documenting this for the edification of others, what's the consensus: is this a bug in mkinitrd(8) that should be reported? (i.e. it should do more sanity checks?) -Adam Thompson athompso(a)athompso.net

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