September 2013 - luv-main

one reason why i like zfs
by Craig Sanders 06 Sep '13

06 Sep '13

I noticed a disk failure just now on one of the drives in my main pool - heard the clicking sound of repeated access attempts so I looked at what 'zpool status' said: pool: export state: DEGRADED status: One or more devices are faulted in response to persistent errors. Sufficient replicas exist for the pool to continue functioning in a degraded state. action: Replace the faulted device, or use 'zpool clear' to mark the device repaired. scan: scrub repaired 0 in 8h12m with 0 errors on Sat Aug 31 10:09:50 2013 config: NAME STATE READ WRITE CKSUM export DEGRADED 0 0 0 raidz1-0 DEGRADED 0 0 0 ata-WDC_WD10EACS-00ZJB0_WD-WCASJ2114122 ONLINE 0 0 0 ata-WDC_WD10EACS-00ZJB0_WD-WCASJ2195141 ONLINE 0 0 0 ata-WDC_WD10EARS-00Y5B1_WD-WMAV50817803 FAULTED 1 2 0 too many errors ata-ST31000528AS_9VP18CCV ONLINE 0 0 0 logs mirror-1 ONLINE 0 0 0 ata-OCZ-VECTOR_OCZ-0974C023I4P2G1B8-part7 ONLINE 0 0 0 ata-OCZ-VECTOR_OCZ-8RL5XW08536INH7R-part7 ONLINE 0 0 0 cache ata-OCZ-VECTOR_OCZ-0974C023I4P2G1B8-part6 ONLINE 0 0 0 ata-OCZ-VECTOR_OCZ-8RL5XW08536INH7R-part6 ONLINE 0 0 0 errors: No known data errors the fix is easy, insert replacement disk and run: # zpool replace -f export ata-WDC_WD10EARS-00Y5B1_WD-WMAV50817803 ata-WDC_WD10EARS-00Y5B1_WD-WMAV50933036 # zpool status -v export pool: export state: DEGRADED status: One or more devices is currently being resilvered. The pool will continue to function, possibly in a degraded state. action: Wait for the resilver to complete. scan: resilver in progress since Wed Sep 4 10:13:09 2013 109G scanned out of 2.78T at 75.9M/s, 10h15m to go 27.3G resilvered, 3.84% done config: NAME STATE READ WRITE CKSUM export DEGRADED 0 0 0 raidz1-0 DEGRADED 0 0 0 ata-WDC_WD10EACS-00ZJB0_WD-WCASJ2114122 ONLINE 0 0 0 ata-WDC_WD10EACS-00ZJB0_WD-WCASJ2195141 ONLINE 0 0 0 replacing-2 FAULTED 0 0 0 ata-WDC_WD10EARS-00Y5B1_WD-WMAV50817803 FAULTED 1 2 0 too many errors ata-WDC_WD10EARS-00Y5B1_WD-WMAV50933036 ONLINE 0 0 0 (resilvering) ata-ST31000528AS_9VP18CCV ONLINE 0 0 0 logs mirror-1 ONLINE 0 0 0 ata-OCZ-VECTOR_OCZ-0974C023I4P2G1B8-part7 ONLINE 0 0 0 ata-OCZ-VECTOR_OCZ-8RL5XW08536INH7R-part7 ONLINE 0 0 0 cache ata-OCZ-VECTOR_OCZ-0974C023I4P2G1B8-part6 ONLINE 0 0 0 ata-OCZ-VECTOR_OCZ-8RL5XW08536INH7R-part6 ONLINE 0 0 0 errors: No known data errors craig -- craig sanders <cas(a)taz.net.au>

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Re: one reason why i like zfs
by Petros 06 Sep '13

06 Sep '13

From: "Petros" <Petros.Listig(a)fdrive.com.au> > Quoting "Petros Listig" <petros(a)fdrive.com.au>: > >> Erm, mdadm emails me when a RAID array fails. I didn't have to write my >> own script, because that's something everybody running an array should >> want (more or less). If I had migrated from md to zfs, I'd have been >> bitten by that. A mismatch of expectations, I guess. Oops, that was Trent. I modified some stuff (cut/paste) and made this mistake. Sorry Peter

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Re: one reason why i like zfs
by Petros 06 Sep '13

06 Sep '13

Quoting "Petros Listig" <petros(a)fdrive.com.au>: > Erm, mdadm emails me when a RAID array fails. I didn't have to write my > own script, because that's something everybody running an array should > want (more or less). If I had migrated from md to zfs, I'd have been > bitten by that. A mismatch of expectations, I guess. I never use scripts or whatever that have to be configured per host. It is just tiresome. There is a icinga/nagios plugin for ZFS health. Icinga is the only "spam robot" in the network. To be honest, I don't look at syslog at all, as long as I am not debugging a problem, or install a new machine, or configure a service. FreeBSD machines send a daily status and security report, they include kernel messages though. My brain is still half asleep when I look at them, and it is more a "pattern matching" as reading, somehow visual memory tells me how these mails should look like, and I wake up if they do not match. It is just for finding Rumfeld's unknown unknowns, the rest is an Icinga/nagios job. The health of a ZFS system is one of the known unknowns and can be observed by the monitor system. I don't need anything else. Regards Peter

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Disk Washing
by David Zuccaro 06 Sep '13

06 Sep '13

What is the best way to wash a disk? I tried this but it is taking forever. dd if=/dev/zero of=/dev/sdg1 Thanks

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Re: Recommendations for APT caching software for Ubuntu?
by zlinw＠mcmedia.com.au 05 Sep '13

05 Sep '13

Chris Samuel > Hi folks, > > What do folks feel works well for them for a running a local apt-cache? > > I want to avoid having to download apt packages for my various Kubuntu > machines for speed rather than quota reasons. While this is not what you really asked............ For accessing any downloaded packages so one can install these on mutiple machines, I use apt-move and create my own repository from the files in /var/apt/cache. I either use an ftp server on one macine or usually back up the whole repository directory to the required machine. I usually keep at least the last two major debian versions. I currently have 5.x 6.x and testing in the repository directory (debian pre 1.0 to 4.x availible on CD's), this is taking up around 80 gig of hardidk space, this is a non-issue these days. The procedure to set up an apt-move repo and using it being fairly simple, mind you I have been doing this now for quite a few years. Installing to a new machine involves copying the repo directory to the data hardisk, install this in the new machine. Boot new machine with debian CD (dvd's being usually to large for me to download). Do a base install only, reboot machine, point apt at the local repo, transfer package selections using method in debian handbook and in say 45 minutes total one has a machine personaly set to your own standard. Lindsay

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Re: Fwd: Disincorporation: why I changed my mind and will vote yes
by Petros 04 Sep '13

04 Sep '13

Hi, in the mentioned case of a ski club (some pressure to adapt a new constitution because of legislation) we wrote the new constitution according to some model rules. We want to present it to the AGM but if it does not get adopted it isn't the end of it. We still exist, just with an outdated constitution. As our president notes, it is still valid because it was established before the new legislation went through (I believe him, I did not check myself) On the way we found some amusing antique staff, as found here too. At the point I am not sure whether I am a LUV member, probably not because I do not remember any forms. I joined a mailing list and that was it. I will not be there tonight, sorry. I will see what happens. But it is probably not wise to rush it through. It just leads to hurt feelings. Why do you have an official organisation in the first place and not just a list and maybe a meeting once a month? I guess the reason for a legal entity is to simplify or enable: 1. Insurance 2. Sponsoring 3. Hiring of venues etc. 4. A public voice 5. A president to blame;-) Okay, maybe 1 to 4 are valid. What else? So the most "legal" staff is not done because it is enjoyable, more out of necessity. So everybody wants to keep it as simple as possible. Linux Australia and LUV have the same motivation, I think: promotion of Open Software and Linux in particular. The rest is a matter of a legal framework, and I have no opinion about it. I am not a lawyer and why else should I care? Regards Peter

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Re: Disincorporation: why I changed my mind and will vote yes
by Petros 04 Sep '13

04 Sep '13

From: "Rick Moen" <rick(a)linuxmafia.com> > > Quoting Petros (Petros.Listig(a)fdrive.com.au) > >> I guess the reason for a legal entity is to simplify or enable: > > Gosh, I've been through all this before. > >> 1. Insurance > > Easy to say without pricing it. I'm guessing that if you ever did, > you'd find that general liabiity insurance for a non-profit association > would be (1) so very prohibitively and astoundingly expensive in annual > premiums that you would give up on the idea, and (2) narrowly written to > cover only the directors and enumerated key officers in the performance > of their delineated duties. If you imagined that it would automagically > cover all activities of volunteers in the organisation, you would be > sadly mistaken. Maybe I should have broadened it with "reliability issues" (e.g. if I step on your foot when you carry a beamer and sue me for 1 Mio Dollars). I make that up because I know that you are always insured for everything but the thing that just occurred. Maybe insurance should be banned as a criminal activity;-) Anyway, for the ski club mentioned the insurance premium is a significant expense but it makes people being involved feeling safer. So far the insurance has a significant impact in this regard. >> 2. Sponsoring >> 3. Hiring of venues etc. >> 4. A public voice >> 5. A president to blame;-) > > None of those is particularly improved by incorporation. (If you > believe otherwise, please state the grounds for your belief.) > >> Okay, maybe 1 to 4 are valid. What else? > > Near as I can tell, not a single one of them is. Well, is there any reason for incorporation? Please let me know. Thanks Peter

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Re: [MLUG] Melbourne geek groups
by Andrew McGlashan 04 Sep '13

04 Sep '13

Hi All, This (edited) list is was posted to MLUG during April, for events / meetings for May, 2013. 1st [1] MelbJS 2nd [2] Melb SEO 3rd [3] 2600 4th [4] Austrek 5th [5] MelbPC 6th [6] MelbournePUG 7th [7a] LUV [7b] RHoK [7c] Melbourne Web Dev 8th [8a] WordPress [8b] Melbourne Perl Mongers 9th [9] Melb Web Accessibility 10th [10] Melb ruby meet & greet 11th [11] Connected Community HackerSpace 14th [14] Melb Nightowls/RORO hack 15th [15] Golang Melbourne 16th [16a] Free Software Melbourne [16b] Drupalchix Meetup 18th [18] DrupalMel Mentoring 20th [20] Hack Melbourne 21st [21a] Melbourne PHP [21b] Responsive Design & JS 23rd [23] Esri Dev Meet 3 27th [27a] Robots & Props [27b] Melbourne Scala 28th [28] Melb Nightowls 29th [29] MLUG 30th [30] Melbourne Ruby [1] http://melbjs.com/ [2] http://www.meetup.com/Melbourne-SEO/events/103258042/ [3] http://2600.org.au/meetings/ [4] http://www.austrek.org/ [5] http://www.webindustry.asn.au/news-and-events/events/melbourne-pc-user-grou… [6] http://wiki.python.org/moin/MelbournePUG [7a] http://luv.asn.au/ [7b] http://www.meetup.com/Random-Hacks-of-Kindness-Melbourne/events/114756342/ [7c] http://www.meetup.com/Melbourne-Web-Developers/events/115674252/ [8a] http://www.wpmelb.org/events/109971102/?eventId=109971102&action=detail [8b] http://melbourne.pm.org/ [9] http://www.meetup.com/Melbourne-Web-Accessibility-Inclusive-Design/events/1… [10] http://www.melbourneruby.com.au/events/114131092/?eventId=114131092&action=… [11] http://www.hackmelbourne.org/meetings/ [14] http://www.meetup.com/Mel-Nightowls/ [15] http://www.meetup.com/golang-mel/ [16a] http://www.freesoftware.asn.au/melb/ [16b] http://www.meetup.com/Melbourne-Drupalchix/events/110853412/ [18] http://www.meetup.com/drupalmelbourne/events/113385522/ [20] http://www.hackmelbourne.org/ [21a] http://phpmelb.org/ [21b] http://www.meetup.com/Melbournemobile/events/108771352/ [23] http://www.meetup.com/Esri-Australia-Dev-Meetup-Melbourne/events/114570722/ [27a] http://www.hackmelbourne.org/meetings/ [27b] http://groups.google.com/group/scala-melb [28] http://www.meetup.com/Mel-Nightowls/ [29] http://www.mlug.org.au [30] http://ruby.org.au/meetups/mel.html >> Almost something for everyday of the month. Does anyone know if there is a good /published/ point of reference that is kept up to date for all the meetings? Thanks AndrewM

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Re: Disk Washing
by Christopher M. Bailey 03 Sep '13

03 Sep '13

Thermite, yep that'll do it :-P -------- Original message -------- From: Daniel Cross <daniel(a)ritualmedia.co.nz> Date: To: David Zuccaro <david.zuccaro(a)optusnet.com.au> Cc: luv-main(a)luv.asn.au Subject: Re: Disk Washing Well, in that case probably Dban will be sufficient for your needs. If still going with dd I agree with the bs=1M switch. Incidentally, a discussion with a friend this evening lead us to the decision that a good way (although involved) to erase a drive would be: 1) Open disk enclusure. 2) Use bench grinder to create aluminium powder from the top of the disk enclosure 3) find something rusty, (or another source of iron oxide) and create powder. 4) mix 50:50 by volume. 5) if available add some magnesium (left over guy fawks sparklers?) 6) pour powder over HDD spindles. 7) Light and step well back while the platters melt. I might try this in coming months and report my results ;) Daniel On Mon, Sep 2, 2013 at 6:30 PM, David Zuccaro <david.zuccaro(a)optusnet.com.au> wrote: On Mon, 2013-09-02 at 17:45 +1000, Daniel Cross wrote: > I guess it depends on your threat model, so rewinding a bit - who are > you wanting to prevent accessing your data? This greatly informs the > conversation. The methods offered above, and in many of the replies > thus far, assume a very sophisticated adversary. > > Daniel Let us assume that the adversary is not a three-letter-government-agency; not that I consent to three-letter-government-agencies accessing any of my information.

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Hostapd, wireless latency and configuration issues
by Jason White 03 Sep '13

03 Sep '13

As discussed before on the list, I've installed a PCI Express 802.11a/b/g/n card to serve as my wireless access point, employing an Atheros 9300 controller. I'm encountering high latency and jitter when I ping any device on the wireless network (i.e., my laptop and a new Android phone). I also discovered that, as reported on various Web sites, the Intel iwl5100/5300 controller in my laptop isn't very reliable under 802.11n. Using the firmware for the card provided at wireless.kernel.org rather than that in the Debian firmware-iwlwifi package yields more reliable throughput however, and seems to reduce the incidence of failure to associate with the access point. Also, it isn't clear to me how best to configure the ht_capab option in /etc/hostapd/hostapd.conf. For the moment, I've copied a sample line published in a post by another user of the same card: ht_capab=[HT40-][HT40+][SHORT-GI-20][SHORT-GI-40][TX-STBC][RX-STBC1][DSSS_CCK-40][LDPC] but naturally I would rather know what I ought to do in this regard. Any suggestions about the latency problems would be welcome as well as general configuration advice. It should be noted that others using the same hardware don't appear to be encountering issues, judging by various blog posts. The kernel here is 3.10-2 from the Debian package currently in Sid.

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