October 2013 - main

[ALUG Announce] Norwich Raspberry Pi User and Developer Group's third meetup
by Steve Pearce 27 Jan '15

27 Jan '15

ALUG Announce Please send announcements to Announce(a)lists.alug.org.uk Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce ----- Greetings ALUG. I'm writing to let you know that we'll be holding the third Norwich Raspberry Pi User and Developer Group meeting next Saturday, 9th March 2013. We'll be meeting at a new venue: The Soup Lab, 5 St. Benedict’s View, Grapes Hill, Norwich, NR2 4HH. See the website norwichrpi.org for more details about the group, and see thesouplab.co.uk for venue info. Hope to see you there. stevepdp ----- Send discussion replies to main(a)lists.alug.org.uk (Reply-To set) Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce

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Best distro for XP users
by Mark Rogers 04 Nov '13

04 Nov '13

I'm being asked quite frequently now for Linux options to replace XP. What would people here pick? Hardware will generally be pretty old so good support for older hardware is important. I note that current Ubuntu versions only get updates for 9 months from release (ie 3 months after they cease to be current) which is fine as long as the next version updates smoothly, but that would depend on continued support for the older hardware, and I know from experience that updates aren't always smooth (typically graphics issues as an older card loses support). I can go with the LTS version of-course, would that be better? Mint follows the same release cycle but doesn't (AFAIK?) provide upgrades. There's no point replacing XP because it's reached EOL with a Linux distro that will go EOL a few months later unless updates are pretty much guaranteed to work without my assistance. (I use Kubuntu in general on my own boxes and would prefer to stick with .deb -based systems, which rules out Fedora/OpenSUSE/etc.) And then there's the choice of desktop - probably something less memory hungry than KDE - or do I look at MATE, Cinnamon, etc with which I have no experience? I'm not great at Linux advocacy because I don't have the confidence in my ability to pick the right option for friends and family who "want" XP... -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) @ 13 Clarke Rd, Milton Keynes, MK1 1LG

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Re: [ALUG] 2600 meeting at 18:00 on Friday the 1st November.
by Steve Engledow 29 Oct '13

29 Oct '13

On 29/10/13 02:00, Viperfang wrote: > Quick heads up about this months Norwich 2600 meeting, > more info at http://www.norwich2600.co.uk So the 2600 reminder is coming through alright then :)

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2600 meeting at 18:00 on Friday the 1st November.
by Viperfang 29 Oct '13

29 Oct '13

Quick heads up about this months Norwich 2600 meeting, more info at http://www.norwich2600.co.uk

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Re: [ALUG] Best distro for XP users
by Phil Wade 28 Oct '13

28 Oct '13

I've recently discovered LXLE (on a Linux Format DVD...) and found it's just the job for replacing XP, especially on older or more limited hardware. I replaced Widows 7 Starter with LXLE on my daughter's Netbook, and she was delighted with the speed and ease of use. I can't see any rough edges, although it's based on Lubuntu that some here say is rough, and it looks and performs really well. 15 minutes of showing her round the OS and she was sorted. The upstream base is Ubuntu LTS - currently 12.04, with 14.04 LTS rather well timed for XP EOL? It's a very young distro, but looks to be well worth trying for all those XP machines out there. The download ISO (which even comes in 64 bit if needed) is a Live DVD. Apparently LXLE stands for Lubuntu eXtra Life Extension - well named. Although I use Mint on my main machines, I'll definitely be leaning to LXLE for those customers who'll need help moving from XP before April 2014 and beyond. Anyone else tried it?

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Diagnosing disk issue
by Mark Rogers 21 Oct '13

21 Oct '13

I have 4x2TB disks configured for RAID5. Initially they were in a USB3 external caddy but this never worked correctly - the raid kept dropping offline before it completed building the array. I then switched to eSATA (same caddy) and that improved things but I still failed to build the array completely. So they're now in a new HP microserver. Until now I assumed the issues were connectivity but since I still have the same problem there must be a disk issue of some kind. However SMART is reporting healthy even after longer self tests. Do I just right this off as a duff disk or can I investigate this further? syslog reports thus: Oct 4 01:30:09 backup kernel: [49309.671201] sd 4:0:0:0: [sdd] Unhandled error code Oct 4 01:30:09 backup kernel: [49309.671217] sd 4:0:0:0: [sdd] Oct 4 01:30:09 backup kernel: [49309.671222] Result: hostbyte=DID_OK driverbyte=DRIVER_TIMEOUT Oct 4 01:30:09 backup kernel: [49309.671229] sd 4:0:0:0: [sdd] CDB: Oct 4 01:30:09 backup kernel: [49309.671233] Read(10): 28 00 d9 2e b1 f0 00 04 00 00 Oct 4 01:30:09 backup kernel: [49309.671253] end_request: I/O error, dev sdd, sector 3643716080 Oct 4 01:30:09 backup kernel: [49309.671264] md/raid:md0: read error not correctable (sector 3643714032 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671274] md/raid:md0: Disk failure on sdd1, disabling device. Oct 4 01:30:09 backup kernel: [49309.671274] md/raid:md0: Operation continuing on 2 devices. Oct 4 01:30:09 backup kernel: [49309.671310] md/raid:md0: read error not correctable (sector 3643714040 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671316] md/raid:md0: read error not correctable (sector 3643714048 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671321] md/raid:md0: read error not correctable (sector 3643714056 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671326] md/raid:md0: read error not correctable (sector 3643714064 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671331] md/raid:md0: read error not correctable (sector 3643714072 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671336] md/raid:md0: read error not correctable (sector 3643714080 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671341] md/raid:md0: read error not correctable (sector 3643714088 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671346] md/raid:md0: read error not correctable (sector 3643714096 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671351] md/raid:md0: read error not correctable (sector 3643714104 on sdd1). Oct 4 01:30:09 backup kernel: [49310.107789] md: md0: recovery done. Oct 4 01:30:09 backup kernel: [49310.170142] RAID conf printout: Oct 4 01:30:09 backup kernel: [49310.170156] --- level:5 rd:4 wd:2 Oct 4 01:30:09 backup kernel: [49310.170163] disk 0, o:1, dev:sdb1 Oct 4 01:30:09 backup kernel: [49310.170167] disk 1, o:1, dev:sdc1 Oct 4 01:30:09 backup kernel: [49310.170171] disk 2, o:0, dev:sdd1 Oct 4 01:30:09 backup kernel: [49310.170175] disk 3, o:1, dev:sde1 Oct 4 01:30:09 backup kernel: [49310.170279] RAID conf printout: Oct 4 01:30:09 backup kernel: [49310.170292] --- level:5 rd:4 wd:2 Oct 4 01:30:09 backup kernel: [49310.170299] disk 0, o:1, dev:sdb1 Oct 4 01:30:09 backup kernel: [49310.170304] disk 1, o:1, dev:sdc1 Oct 4 01:30:09 backup kernel: [49310.170309] disk 2, o:0, dev:sdd1 Oct 4 01:30:09 backup kernel: [49310.170322] RAID conf printout: Oct 4 01:30:09 backup kernel: [49310.170325] --- level:5 rd:4 wd:2 Oct 4 01:30:09 backup kernel: [49310.170329] disk 0, o:1, dev:sdb1 Oct 4 01:30:09 backup kernel: [49310.170332] disk 1, o:1, dev:sdc1 Oct 4 01:30:09 backup kernel: [49310.170336] disk 2, o:0, dev:sdd1 Oct 4 01:30:09 backup sSMTP[10706]: Unable to locate mail Oct 4 01:30:09 backup sSMTP[10706]: Cannot open mail:25 Oct 4 01:30:09 backup mdadm[3415]: Fail event detected on md device /dev/md0, component device /dev/sdd1 Oct 4 01:30:09 backup kernel: [49310.172571] RAID conf printout: Oct 4 01:30:09 backup kernel: [49310.172578] --- level:5 rd:4 wd:2 Oct 4 01:30:09 backup kernel: [49310.172585] disk 0, o:1, dev:sdb1 Oct 4 01:30:09 backup kernel: [49310.172589] disk 1, o:1, dev:sdc1 Oct 4 01:30:09 backup mdadm[3415]: RebuildFinished event detected on md device /dev/md0 Mark -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) @ 13 Clarke Rd, Milton Keynes, MK1 1LG

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Getting started with Linux and electronics
by Mark Rogers 21 Oct '13

21 Oct '13

Although not strictly OT here, there's almost certainly better places, so can anyone recommend any friendly mailing lists for getting started with using Linux to talk to GPIO etc? The sort of thing you might use a Pi or BeagleBone for (but not specific to a single platform). I've got several Pi's, a BB Black (and an Arduino for good measure) sitting around not really being used for much, and I really should learn to do some interesting things with them. There are loads of forums and Google Groups but I just prefer mailing lists like this one. Specific examples of the sort of thing I want to do: For personal use I want to do something interesting with Christmas lights, probably running from a solar charged 12V battery - that feels like it should give me plenty of scope to "play". Also, a colleague has asked about a simple application to record encoder and analogue input values to CSV on a periodic basis. In each case I can't even decide whether I should be looking at Arduino or Pi/BBB hence looking for a more general mailing list than one targeted at a specific solution. -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) @ 13 Clarke Rd, Milton Keynes, MK1 1LG

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[ALUG Announce] 3rd Monday Monthly Ipswich Social Meeting : The Mulberry Tree
by samwise 21 Oct '13

21 Oct '13

ALUG Announce Please send announcements to Announce(a)lists.alug.org.uk Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce ----- The monthly "Third Monday" ALUG Ipswich Social Meeting is back today, 21st October, at 20:00: The Mulberry Tree 5 Woodbridge Road IPSWICH IP4 2EA Tel: 01473 225776 Map/Directions URI: http://maps.google.co.uk/?q=IP4+2EA WWW: https://www.facebook.com/MULBERRYHOSPITALITY The Mulberry Tree, previously known as The Milestone Beer House, is a grade 2 listed building in the centre of Ipswich. It is located at the intersection between Woodbridge Road and the A1156, across the road from the old Odeon cinema and not far from the Regent Theatre. It re-opened on Thursday March 29th 2012 after a major refurbishment, under its original name of The Mulberry House and has already begun to regain a good reputation for its selection of beers and ales. It has a sizeable car park to the rear of the building. All are welcome, novices and experienced users. Feel free to ask for further information on the Main ALUG mailing list. Cheers, Peter. ----- Send discussion replies to main(a)lists.alug.org.uk (Reply-To set) Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce

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Recording event data efficiently
by Mark Rogers 18 Oct '13

18 Oct '13

I need to record changes in values of several variables (in this case around 9000) so that I can display their changes against time on a graph. I'd like a resolution of around 1min, however, I don't need to sample these values every minute because any change in value is available to me so the values only change on event. Storing a sample every minute for 9000 variables is about 1.3MB/day (each sample is a single byte). But that should compress heavily because for most of the time any given value will be static. So, what would be the best way to store these values for graphing? Recording the events in a database would be efficient storage but is not great for generating graphs from. (Graphs would be along the lines of what MRTG generates, at a rough guess, although that's not a tool I've used in anger. I looked at the MRTG log file format but unless I'm reading the spec wrong I don't think it's quite what I want.) If it matters, I plan on doing this on an ARM-based SBC such as a Pi or Beaglebone. Mark -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) @ 13 Clarke Rd, Milton Keynes, MK1 1LG

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SQL injection
by Mark Rogers 17 Oct '13

17 Oct '13

A payment gateway that a client is using is reporting that data we're submitting to it is triggering an SQL injection warning, and as a result the connections are being rejected (the end user is in the payment stage on a shopping cart and it being told that their IP is being blocked, which isn't very nice). The string they're apparently picking up on is: (Size:Medium (Size 12) )|27.4917 and specifically the ') )|27' part of it. The error being generated is: Possible SQL injection attack (detectSQLi)"] [data "s))o1,ARGS:xxxx" Other strings have triggered this where the number is different, it seems to be ))|<number> that causes a problem. (xxxx is the field we're submitting the value in, edited so as not to identify the payment gateway in use) Any suggestions as to what SQL attack this is trying to catch? I can't think of anything where ))|27 would represent an SQL injection attack. At the moment the payment gateway is just telling us to remove that string (they haven't given us an option to escape/encode it) which makes no sense. I'd like to know if this is part of a set of standard rules they're using that makes sense to someone or a homegrown set that might not. Mark -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) @ 13 Clarke Rd, Milton Keynes, MK1 1LG

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