- Roundtable - muug.ca

Re: [RndTbl] ZFS I/O strangeness
by Adam Thompson 03 Mar '12

03 Mar '12

I get the best performance out of dd(1) at 8MB block size, but it's still less than if I cat and pipe. It's standard GNU cat, which does not do anything fancy like that AFAIK. Possibly Solaris has enormous pipelines, and has wildly optimized multi-processor I/O, so two processes are faster than one?? -Adam Gilles Detillieux <grdetil(a)scrc.umanitoba.ca> wrote: >I'd expect the readahead to be the same for the two commands, as it >should all happen behind the scenes at the filesystem level. Or does >the C library, or the cat command itself, do its own readahead? More >likely cat is using a different input buffer size than 8k and that is >resulting in the extra efficiency. I'd try different bs= values on the >first dd command to see if that helps. > >On 03/03/2012 12:52 PM, Adam Thompson wrote: >> I have a ZFS RAIDZ3 filesystem under OpenSolaris (actually a Nexenta build >> so a GNU userland on top of OpenSolaris kernel). >> >> "dd if=filename of=/dev/null bs=8k" gives me ~66Mbytes/sec. >> "cat filename | dd of=/dev/null bs=8k" gives me ~142Mbytes/sec. >> >> WTF? Why would using cat *increase* the overall speed? >> The only thing I can think of is readahead, but why would cat cause that >> to happen while dd doesn't? >> >> -Adam Thompson >> athompso(a)athompso.net >> >> >> >> _______________________________________________ >> Roundtable mailing list >> Roundtable(a)muug.mb.ca >> http://www.muug.mb.ca/mailman/listinfo/roundtable > >-- >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) > >_______________________________________________ >Roundtable mailing list >Roundtable(a)muug.mb.ca >http://www.muug.mb.ca/mailman/listinfo/roundtable >

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Fwd: USENIX/ACM NSDR '12 Call For Papers Now Available
by Gilbert E. Detillieux 02 Mar '12

02 Mar '12

FYI... -------- Original Message -------- Subject: USENIX/ACM NSDR '12 Call For Papers Now Available Date: Fri, 2 Mar 2012 12:33:24 -0800 From: Lionel Garth Jones <lgj(a)usenix.org> On behalf of the 6th USENIX/ACM Workshop on Networked Systems for Developing Regions (NSDR '12) program committee, we invite you to submit papers that propose and discuss ideas concerning the design, implementation, and evaluation of new computing and communications technologies to support the sustainable development of developing regions. Please submit all paper titles and abstracts by March 27, 2012, 11:59 p.m. PDT. NSDR focuses on the technical networking and systems research challenges that arise in the design, implementation, and deployment of new computing solutions appropriate for developing regions. We encourage the submission of position papers or the results of preliminary work describing interesting, original, previously unpublished ideas or results pertaining to the design, implementation, and/or evaluation of networks and systems for developing regions. Areas of interest include, but are not limited to: * Low-cost wireless connectivity * Intermittent and delay-tolerant systems * Rural network planning * Spectrum management protocols and techniques * Mechanisms for emergency and urgent communications * Location-aware systems * Power-efficient systems * Low-cost computing devices * Mobile systems and applications * Middleware and mechanisms for minimizing energy, latency, and storage (caching, etc.) * Adapting content and applications for local languages * User interfaces for low-literacy populations * Shared access devices and infrastructure, including personalization and privacy concerns * Design and evaluation of applications and in-depth case studies in the areas of public health, microfinance, agriculture, e-governance, education, monitoring, disaster management, etc. Paper submissions are due Tuesday, March 27, 2012, 11:59 p.m. PDT. For more details on the submission process, please see the complete Call for Papers at: http://usenix.org/conference/nsdr12/ We look forward to receiving your submissions! Kameswari Chebrolu, Indian Institute of Technology, Bombay Brian Noble, University of Michigan USENIX NSDR '12 Program Co-Chairs nsdr12chairs(a)usenix.org --------------------------------- Call for Papers 6th USENIX/ACM Workshop on Networked Systems for Developing Regions June 15, 2012 Boston, MA http://usenix.org/conference/nsdr12 Submissions due: March 27, 2012, 11:59 p.m. PDT. Notification to authors: April 26, 2012 Electronic files of final papers due: May 14, 2012 ---------------------------------

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Identifying Intel NICs
by Adam Thompson 20 Feb '12

20 Feb '12

I just found this document on the Intel website: http://www.intel.com/support/network/sb/cs-012904.htm It provides a pretty-much-complete cross-reference of all their NICs and LOMs with part#, PBA#, PCI ID, and the link to the appropriate drivers. The footer SAYS this document was created back in 2004, but I know searching for this data on Intel’s website didn’t turn this up as recently as last year. Hope this helps someone else! -Adam Thompson athompso(a)athompso.net

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seeking 1U/2U server
by Adam Thompson 20 Feb '12

20 Feb '12

I'm looking for a cheap 1U or 2U server that won't cost me more in shipping than the server itself (i.e. local pickup, ideally). Dual P-III Xeon 1.0GHz or better. (Yes, seriously. Newer CPUs are OK, too.) Dual onboard Gigabit Ethernet, *or* 64-bit PCI ("PCI-X") slot. Must have mounting rails. If you have an old rackmount server you want to get rid of, or know someone who does, please let me know. Thanks, -Adam Thompson athompso(a)athompso.net

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MUUG Meeting, February 21, 7:30pm -- Linux LVM
by Gilbert E. Detillieux 15 Feb '12

15 Feb '12

*A reminder that this meeting is next Tuesday.* (Hope you didn't show up last night!) The Manitoba UNIX User Group (MUUG) will be holding its next monthly meeting on Tuesday, February 21. The meeting topic for this month is as follows: Linux LVM One of the most important new developments in the Linux 2.6 kernel was the Logical Volume Manager, version 2 (or LVM 2). Logical volume management is a widely-used technique for deploying logical rather than physical storage. With LVM, "logical" partitions can span across physical hard drives and can be resized (unlike traditional ext3 "raw" partitions). Kevin McGregor will summarize the basic principles behind the LVM and provide examples of basic operations which can be performed with it. February's RTFM will feature the traceroute(1) command, presented by our president, Katherine Scrupa. 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 meeting location: The IBM offices, at 400 Ellice Ave. (between Edmonton and Kennedy). When you arrive, you will have to sign in at the reception desk, and then wait for someone to take you (in groups) to the meeting room. Please try to arrive by about 7:15pm, so the meeting can start promptly at 7:30pm. Don't be late, or you may not get in. (But don't come too early either, since security may not be there to let you in before 7:15 or so.) Non-members may be required to show photo ID at the security desk. Limited parking is available for free on the street, either on Ellice Ave. or on some of the intersecting streets. Indoor parking is also available nearby, at Portage Place, for $5.00 for the evening. Bicycle parking is available in a bike rack under video surveillance located behind the building on Webb Place. ********************************************************************** 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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Re: [RndTbl] Networking over home power lines
by Dan Keizer 14 Feb '12

14 Feb '12

Thanks Sean -- nothing like a pair of pager systems in the backyard :-) Lucky for me -- we're far away from any commercial setup -- but I have enough RF-generating noise from the rack of computers downstairs ... it's amazing how much RF is around us ... with most modern wireless setups, they are fairly wide open on the front-end that any noise that is around it can sometimes saturate it ... Dan. From: Sean Walberg <sean(a)ertw.com> > Date: 14 February 2012 14:45 > Subject: Re: [RndTbl] Networking over home power lines > To: Continuation of Round Table discussion <roundtable(a)muug.mb.ca> > > > If they're extra noisy, lend them to Dan's neighbours. :) > > Sean > > > On Tue, Feb 14, 2012 at 3:30 PM, Bill Reid <breid.wpg(a)gmail.com> wrote: > >> I have a pair of Ethernet over power line units if you want to try them >> out. >> >> >> On 14/02/12 12:57, John Lange wrote: >> >>> Just to be clear, I'm 100% certain that there is no transformer >>> between the buildings. Thats what I meant by "the same power system". >>> >>> On Tue, Feb 14, 2012 at 12:43 PM, ve4drk(a)gmail.com<catchall(a)**keizer.ca<catchall(a)keizer.ca>> >>> wrote: >>> >>>> these ethernet over power technologies spew RF everywhere) but would >>>> certainly look more to a wireless scenario. >>>> >>> >>> heh.. Just chucking at the irony of that statement ;) >>> >>> John >>> ______________________________**_________________ >>> Roundtable mailing list >>> Roundtable(a)muug.mb.ca >>> http://www.muug.mb.ca/mailman/**listinfo/roundtable<http://www.muug.mb.ca/mailman/listinfo/roundtable> >>> >>> ______________________________**_________________ >> Roundtable mailing list >> Roundtable(a)muug.mb.ca >> http://www.muug.mb.ca/mailman/**listinfo/roundtable<http://www.muug.mb.ca/mailman/listinfo/roundtable> >> > > > > -- > Sean Walberg <sean(a)ertw.com> http://ertw.com/ > > _______________________________________________ > Roundtable mailing list > Roundtable(a)muug.mb.ca > http://www.muug.mb.ca/mailman/listinfo/roundtable > > >

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Networking over home power lines
by John Lange 14 Feb '12

14 Feb '12

>From the bit of reading I've done, it appears that a standard for networking over power lines was ratified in September 2010. Linksys has a device (plek400) for about $100. What I can't seem to find out is what the maximum theoretical distance the signal can travel? I have a situation where I'd like to get a network drop into a building that is 400m away. I've toyed with the idea of a home-brew Wifi point-to-point system but it's still relatively expensive to buy two Buffalo radios plus external antennas etc. and even then it would be on the outside of the range for that type of solution. The building is defiantly on the same power "system" so can the network-over-power devices reach 400m ? John

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Re: [RndTbl] Networking over home power lines
by Dan Keizer 14 Feb '12

14 Feb '12

I was in the middle of typing a reply that says basically the same thing -- I guess I'm not as fast at typing these days :-) Basically, the same thing -- The biggest hing you need to look at is to find out if the two end-points exist on the same side of the mains. Is this commercial or residential? If it's down the road, then it may be on a separate transformer as well. Even from a residential perspective, you can have issues since you have two lines coming into the house - you may have one circuit on one side and another circuit on the other side -- the transmission may not go through/cross-over the remote transformers. Similar issues arise from X10 usage as well ... different frequencies, but similar issues. Naturally, injecting the type of frequencies these use into the circuitry of your house can also cause that same injection to show up unwanted on devices that receive on those frequencies ... ie: radios and the like. Interference may show up. I'm not an advocate of Ethernet-over-power, (I'm a ham radio operator and these ethernet over power technologies spew RF everywhere) but would certainly look more to a wireless scenario. Dan. On 14 February 2012 12:34, Robert Keizer <robert(a)keizer.ca> wrote: > My understanding is that a transformer will block that frequency. I > had looked into it for a while and I read some people making block > wide networks, but the at least in their situation the transformer at > the end of the block was filtering. > > Keep the list updated, this is interesting stuff. :) > > Rob > > On Tue, Feb 14, 2012 at 11:48 AM, John Lange <john(a)johnlange.ca> wrote: > > From the bit of reading I've done, it appears that a standard for > > networking over power lines was ratified in September 2010. > > > > Linksys has a device (plek400) for about $100. What I can't seem to > > find out is what the maximum theoretical distance the signal can > > travel? > > > > I have a situation where I'd like to get a network drop into a > > building that is 400m away. I've toyed with the idea of a home-brew > > Wifi point-to-point system but it's still relatively expensive to buy > > two Buffalo radios plus external antennas etc. and even then it would > > be on the outside of the range for that type of solution. > > > > The building is defiantly on the same power "system" so can the > > network-over-power devices reach 400m ? > > > > John > > _______________________________________________ > > Roundtable mailing list > > Roundtable(a)muug.mb.ca > > http://www.muug.mb.ca/mailman/listinfo/roundtable > _______________________________________________ > Roundtable mailing list > Roundtable(a)muug.mb.ca > http://www.muug.mb.ca/mailman/listinfo/roundtable >

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The other shoe drops at Nokia...
by Gilbert E. Detillieux 10 Feb '12

10 Feb '12

Well, this probably won't come as a surprise to anyone here, but Nokia is now officially dropping support for everything but Windows Phone, for all mobile devices going forward... http://www.itworldcanadacurated.com/itwcc/permalink/89415889-THE-MICROSOFT-… http://www.businessinsider.com/the-microsoft-investor-feb-9-2012-2 -- 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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MUUG Meeting, February 21, 7:30pm -- Linux LVM
by gedetil＠cs.umanitoba.ca 07 Feb '12

07 Feb '12

*Please note the date change for this meeting, which is a week later.* The Manitoba UNIX User Group (MUUG) will be holding its next monthly meeting on Tuesday, February 21. The meeting topic for this month is as follows: Linux LVM One of the most important new developments in the Linux 2.6 kernel was the Logical Volume Manager, version 2 (or LVM 2). Logical volume management is a widely-used technique for deploying logical rather than physical storage. With LVM, "logical" partitions can span across physical hard drives and can be resized (unlike traditional ext3 "raw" partitions). Kevin McGregor will summarize the basic principles behind the LVM and provide examples of basic operations which can be performed with it. February's RTFM will feature the traceroute(1) command, presented by our president, Katherine Scrupa. 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 meeting location: The IBM offices, at 400 Ellice Ave. (between Edmonton and Kennedy). When you arrive, you will have to sign in at the reception desk, and then wait for someone to take you (in groups) to the meeting room. Please try to arrive by about 7:15pm, so the meeting can start promptly at 7:30pm. Don't be late, or you may not get in. (But don't come too early either, since security may not be there to let you in before 7:15 or so.) Non-members may be required to show photo ID at the security desk. Limited parking is available for free on the street, either on Ellice Ave. or on some of the intersecting streets. Indoor parking is also available nearby, at Portage Place, for $5.00 for the evening. Bicycle parking is available in a bike rack under video surveillance located behind the building on Webb Place. ********************************************************************** 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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