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Have I bought the wrong kit?
by Chris Walker 11 Jan '13

11 Jan '13

I am fed up with the cheap Huawei router that Talktalk supply so decided I would go for something that will run ddwrt. Having looked at the ddwrt site, I then started looking at Amazon. I decided I would buy a Buffalo Air Station and went for a WZR-HP-AG300H. But it tells me I should connect it to my modem. <Thinks> Hmm. Thought that was built-in. Look again at spec. B*gger. So should I buy a cheap ADSL modem or ask Amazon if they'll take it back and buy another Air Station but this time, one with the correct specs?

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Barebones
by Laurie Brown 11 Jan '13

11 Jan '13

Over the last few years, we have been building small servers using Asus barebones systems. They've been great, and we can install whatever CPU we like, disks, memory, flavour of Linux and so on. They have proven to be relatively cheap and highly reliable machines. However, I just can't seem to find them any more! Our requirement is room for at least 3 SATA disks, preferably 4 plus DVD, multi-core CPU, preferably AMD, good PSU, and capable of taking at least 8Gb of memory. I can find loads of tiny machines great for firewalls and so on, but nothing any larger. Even the Shuttles, still easily found, can't hold enough disks. Does anyone know of a reliable supplier of Asus barebones, or something similar? The last thing I want to do is spend 4 figures on an HP and throw away a licence for Winblow$. Yes, I know I can buy a case, mobo and so on, but that's a laborious exercise if regular, and kit becomes obsolete so fast, it has to be repeated almost every time we build a machine. We've looked at Zoostorm, which is the closest I can find, but they aren't barebones, and we don't need a 2tb disk, just because we want 8Gb of memory. With Zoostorm, it seems that the higher the CPU/memory spec, the bigger the disks, and so on, and it's very hard to find out what the mobo is, and whether it's Linux-friendly. Just too many unknowns and potentially expensive pitfalls. Help/guidance greatly appreciated! Cheers, Laurie. -- --------------------------------------------------------------------- Laurie Brown laurie(a)brownowl.com ---------------------------------------------------------------------

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Going spare...
by Mark Rogers 11 Jan '13

11 Jan '13

I have this motherboard, with CPU (couldn't tell you what CPU from memory): http://reviews.cnet.com/motherboards/abit-nf7-s2g-motherboard/4505-3049_7-3… Could likely find some RAM to go with it. Socket A so not high spec, but might be a good replacement for a failed board. I also have at least one Fujitsu Siemens Econel server with dead motherboard (PSU and CPU fine, I believe). Good solid metal cases with loads of drive bays etc, but not worth repairing. Should take standard motherboards if you can find one that the CPU fits relative to where the PSU is. Free for collection from Peterborough. 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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Nice confirmation of mail not getting lost when SMTP server isn't available
by Chris Green 11 Jan '13

11 Jan '13

Over the past few days I have been playing about with the DNS on my LAN (changing which server runs dnsmasq, etc.). Last night around 22:00 I left everything, as I thought, running OK. This morning though no E-Mails had arrived on my desktop (which is also the SMTP server). It turned out that I hadn't restarted things enough and my dekstop had got a randomly assigned IP address rather than the fixed one it should have got (by telling dnsmasq its MAC address). So TsoHost's mail system hadn't been able to deliver mail to zbmc.eu for something like 12 hours. It was a good test for two things:- My offsite mail backup to which I deliver all my mail in parallel to delivery to my dekstop worked perfectly, so I could see all the undelivered mail there. When I fixed the IP address of my desktop all the undelivered mail arrived on my desktop after an hour or two. Isn't it nice when things work as they should! :-) -- Chris Green

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Anyone use x2go or similar software?
by Chris Green 11 Jan '13

11 Jan '13

I was considering using VNC to access another box on my LAN but as the remote system (which would run a VNC server) doesn't currently have X running on it (though there's a Lubuntu desktop available) it makes VNC rather awkward. I've seen x2go recommended for this sort of situation as it seems as if it's more oriented towards the sort of thing I want to do - fire up an X session and use it remotely. While it would be nice if one could use 'old fashioned' X as it was originally designed it tends not to work so well with very many programs now using dBus to communicate. E.g. if I try and run nm-connection-editor on the remote system via an "ssh -x remote-system" connection it pops up a window on my system but there's an error:- ** (nm-connection-editor:3088): WARNING **: Couldn't connect to accessibility bus: Failed to connect to socket /tmp/dbus-9FFbE3UfRz: Connection refused ... and it doesn't actually work. Or can anyone suggest how to get around the dBus communication issue? -- Chris Green

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Full size but low power PCs - does nobody sell them? (maybe related to Laurie's recent question)
by Chris Green 10 Jan '13

10 Jan '13

Why is it that no one seems to sell 'ordinary' PCs, in ordinary sized boxes, but with reasonably power efficient components. It's next to impossible to even find out what the power consumption is of most desktop PCs and very few of them have efficient power supplies (often the worst offender). It's all very well advocating little Intel Atom based boxes but they almost never have any space for extra disk drives. The same applies to Raspberry Pi etc., very low power but no easy way to assemble in a box with a couple of disk drives. I guess I'm after much the same as Laurie but with maybe more emphasis on power consumption. A basic case with low power mother board, low end processor, etc. and space for several disks. -- Chris Green

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Are there any linux based NAS systems out there with reasonable audio output?
by Chris Green 10 Jan '13

10 Jan '13

I want a compact, low power Linux box to use as a NAS and audio streamer (probably running mpd). This is a slightly odd mix of requirements, does anyone have any suggestions of what to look at? Alternatively maybe a 'media streamer' would provide what I want, but I need it to have audio outputs and be able to run something like mpd so that it can run headless and be driven remotely. A custom built Linux box is a valid possibility too but getting a small, low-power one isn't trivial. (Raspberry Pi is out because its audio is notoriously bad and there seem to be few workarounds to avoid its sound problems) -- Chris Green

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Re: [ALUG] Full size but low power PCs - does nobody sell them? (maybe related to Laurie's recent question)
by Chris Green 10 Jan '13

10 Jan '13

On Thu, Jan 10, 2013 at 04:47:47PM +0000, Anthony Anson wrote: > On 10/01/13 16:19, Chris Green wrote: > >Why is it that no one seems to sell 'ordinary' PCs, in ordinary sized > >boxes, but with reasonably power efficient components. > > If you don't feel competent to build one from scratch, go to a > proper computer shop (where are you? I can recommend some in the > Norwich area.) and they will put one together for you - probably > cheaper than you could. > I've been building my PCs since quite a long time ago (like since they were 386 processors, and NextGen processors - remember them?). However nowadays it doesn't really make economic sense. > >It's next to impossible to even find out what the power consumption is > >of most desktop PCs and very few of them have efficient power supplies > >(often the worst offender). > > > >It's all very well advocating little Intel Atom based boxes but they > >almost never have any space for extra disk drives. The same applies to > >Raspberry Pi etc., very low power but no easy way to assemble in a box > >with a couple of disk drives. > > Not a tremendous challenge though. > It's not a challenge putting a Raspberry Pi in a box and adding some USB disks, no. However it won't be a particularly good server. The difficulty is finding out which motherboards are low power and then finding a suitably efficient power supply. My desktop machine (Intel I3, 8Gb memory, two 1Tb disks) consumes only about 40 watts because I chose a reasonably low power board (after much searching to find information) and an efficient power supply. It's still a *bit* of a bodge though because the power supply isn't designed to fit in a standard box. Since my system only uses 40 watts it needs a much smaller power supply than most full-sized PC ones. Even a very efficient 300 watt power supply isn't going to be particularly good at 40 watts. I'm using an 80 watt supply. > >I guess I'm after much the same as Laurie but with maybe more emphasis > >on power consumption. A basic case with low power mother board, low end > >processor, etc. and space for several disks. > > Then you can run Tom's RTBT and have a low-end OS too? > > This is where your competent small trader scores. Try Anglian Internet. > I'd be *really* surprised if they know power consumption figures for assembled PCs (before they assemble them that is, I can measure the consumption of something I've built). I will send them an enquiry though. -- Chris Green

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Reassembling RAID array
by Mark Rogers 10 Jan '13

10 Jan '13

I had a RAID5 array set up as /dev/md1 using 4 external USB3 drives. Following a reboot (I assume, although to be honest I'm not sure what caused it) the array hasn't come back up correctly: $ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md1 : active raid5 super 1.2 level 5, 512k chunk, algorithm 2 [4/0] [____] md0 : active raid5 sda1[0] sdb1[1] sdd1[3] sdc1[2] 5860535808 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU] unused devices: <none> Note: /dev/md0 is a separate array and is working fine; md1 should comprise sd[fghi]1 All the "missing" partitions are present, eg: $sudo fdisk -l /dev/sdf Disk /dev/sdf: 2000.4 GB, 2000398934016 bytes 81 heads, 63 sectors/track, 765633 cylinders, total 3907029168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x2c2d5341 Device Boot Start End Blocks Id System /dev/sdf1 2048 3907029167 1953513560 fd Linux RAID autodetect (same applies for the other three disks). How do I get mdadm to add my disks into the array, both now and after a reboot? -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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Best way to code a linux comms daemon
by Mark Rogers 09 Jan '13

09 Jan '13

Occasionally I have the need to write some communications software, typically something that connects to a serial or TCP port, writes requests and reads responses, writing the results into a database. Usually the basics are simple enough to achieve, but the challenge is in making a robust solution that will cope with lost connections and any other variety of reasons why things might go wrong (including bugs in the script itself). What is the "best" way to approach something like this? Are some programming languages better than others for this? What's the best way to ensure a script restarts if it fails for some reason? I'm looking for something Debian/Ubuntu based if relevant. [Aside: One reason for asking is that I have been playing with an app I downloaded that talks to CurrentCost power meters, with a PHP-based web interface and a Python-based daemon, and I'm not sure why Python was chosen for it; also I note that the daemon regularly crashes on my system leaving me without any data.] -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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