January 2013 - luv-main

P2V: Linux RAID1 -> Virtual disk or similar... how would you go about it?
by Anthony Hogan 29 Jan '13

29 Jan '13

Hi all, A friend has an aging linux server on which he runs a web app that he custom built. The web app's written in Perl and has grown organically with libraries and other dependencies added over the years. The server's getting a bit long in the tooth and my concern is a proper backup is needed. My first instinct is that given he doesn't have an exact handle on dependencies etc. he needs to ensure that he has a backed up copy of the entire system "as is"... and that for backup purposes as well as having something to properly dev on, a virtual machine is the way to go. With a virtual machine, one then has some breathing space to do proper dependency analysis etc. in preparation for a clean OS install and should current hardware die, provided that file and db changes have been backed up in interim, wouldn't be too hard to switch over to VM. The server uses Linux software RAID1 # mdadm --detail /dev/md1 /dev/md1: Version : 00.90.03 Creation Time : Sun Mar 26 17:57:19 2006 Raid Level : raid1 Array Size : 76196224 (72.67 GiB 78.02 GB) Used Dev Size : 76196224 (72.67 GiB 78.02 GB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 1 Persistence : Superblock is persistent Update Time : Mon Jan 28 17:35:20 2013 State : active Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 How would you image the system, to P2V it? In theory I think one could: * Image a single drive to a virtual disk.. boot into degraded state, recover or drop raid. * Image both drives to virtual disks.. boot into normal state * Build a VM using same underlying OS then using a live environment on both systems, rsync files from source over destination, overwriting destination entirely.. Fix fstab/raid config.. Not entirely sure on which tools to use tho to do this, pitfalls and such.. Also friend wants to minimise downtime as the webapp powers a relative's web store.

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Re: dpkg -l and apt
by zlinw＠mcmedia.com.au 25 Jan '13

25 Jan '13

Quoting Rick Moen <rick(a)linuxmafia.com> > Quoting James Harper (james.harper(a)bendigoit.com.au) > >> When I do 'apt-get update', 'dpkg -l' doesn't know about the new >> packages and so isn't useful for searching. > > > Wrong tool. I think you're looking for 'apt-cache'. just for the record........ Its likely dpkg -l uses the file /var/lib/dpkg/available as its source this is updated by dselect. One can update this file by running dselect and selecting the menu item "1. [U]pdate". I use apt-get, dselect and dpkg, each has its own strengths and weakness's. I find dselect particularly good at telling one what is being drag into satisfy dependecies, in many cases (for me any way) telling you its pulling something you ____really____ do not want. I do not want a system with a lot of stuff on it I will never use, apt being real good at installing masses of stuff although..... Install-Recommends "false"; Install-Suggests "false"; in /etc/apt/apt.conf helps a lot. Lindsay

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dpkg -l and apt
by James Harper 25 Jan '13

25 Jan '13

When I do 'apt-get update', 'dpkg -l' doesn't know about the new packages and so isn't useful for searching. How do I update dpkg's database these days? Or how can I do a similar search in apt's database? I know I used to be able to do it with dselect but I much prefer the command line when searching. Thanks James

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Wifi connection issues.
by stripes theotoky 25 Jan '13

25 Jan '13

Dear Group, I have two Linux laptops with the latest updates to the most recent LTS Ubuntu distribution. 1). Samsung netbook. This uses the Broadcom wl wifi driver and works fine all the time everywhere. 2). Lenovo W520. This uses the iwlwifi driver and works on every network I have tried it on except Latrobe University. I have tried both LTUwireless2 or Eduroam. It is impossible to keep a connection to either of these (in La Trobe) for longer than about 2 minutes. Outside La Trobe Eduroam works just fine. The configuration settings are the same on both boxen. Up until a few months ago the W520 worked fine on the La Trobe network. IT support claim that no Linux box can connect to their wifi or ever could. As I was using it with the Samsung half an hour ago I know this is false. Obviously something has changed but where to start looking, is it my driver, my hardware or has something changed on the network and if so what. Ideas most welcome Stripes

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Web site with problems (with Linux browsers only)
by Peter Ross 25 Jan '13

25 Jan '13

Hi, a friend of mine is running a Joomla based website http://www.DeutscheInMelbourne.net . The first page renders fine on Windows and Apple devices but has a full page of spam gibberish <a href>'s to the most wanted items if I believe in spam) before the header menu starts (so I have to scroll down to see any useful content) I tried on two Ubuntu machines running Ubuntu 12.04, and tried Chrome and Firefox, always with the rubbish in it. Stranger, it does not even appear in the page source if I look at it using Windows or Apple machines. I did not look at the server yet (and my friend isn't an IT expert) but I find it that weired that I don't have a slightest idea what the cause might be. Any ideas? Thanks for answers Peter

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Re: remote list of changed files
by Brian May 24 Jan '13

24 Jan '13

On 24/01/2013 12:16 PM, "Russell Coker" <russell(a)coker.com.au> wrote: > Unison sounds interesting, it's something to consider for future uses, thanks > John Mann. While unison is good (I use it all the time), it is no longer actively developed. See http://www.cis.upenn.edu/~bcpierce/unison/status.html

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Postfix - limiting number of recipients
by Peter Ross 24 Jan '13

24 Jan '13

Hi all, I wonder whether I can prevent outgoing "bulk e-mail". A disgruntled leaving employee was threatening sending mail to all customers. (It did not happen but management was very unhappy and asked what I could do against it, from the technical side). I have a postfix mail relay (upstream going to the provider) but I cannot see a way of telling it "reject all mails with more than 50 addresses in the header", as an example. We have a special "list server" to fascilitate legitimate sending to many recipients at the time. It is bypassing this relay - so I don't have to worry about it. Thanks for answers Peter

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Re: remote list of changed files
by Andrew McGlashan 24 Jan '13

24 Jan '13

Hi, On 24/01/2013 12:16 PM, Russell Coker wrote: > The -n and -i options suggested by Chris and James are useful. They do what I > originally wanted to do. But it turns out that the batch support is even > better. The rsync people are really smart. Whilst I did learn a thing or two with this thread, thank you very much, I am astounded that you can seem to have no trouble reading Wikipedia articles to attack people, but you can't seem to read a man page? It's not the first time something so basic about a Linux tool or operation has escaped your vast experience and that really surprises me. The other most significant oversight from you was the checkarray processing of software RAID. Just the same, interesting, I'm sure you are a very knowledgeable Linux user, but sometimes I just wonder in total amazement. Cheers A.

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Recommendations for a new cable modem
by Matthew Cengia 22 Jan '13

22 Jan '13

Hi all, TL;DR ===== I'm looking for an Optus-approved cable modem whose Ethernet port I can plug into my WNDR3800 router such that the WNDR3800 is directly exposed to the public IP address, with no private addressing or NAT in the way. Which one, if any, should I choose? Long version ============ Where I live, I'm stuck with Optus cable as my broadband internet (short story is we're too far from the exchange to get ADSL, despite being in the middle of suburban Melbourne), and we're looking at upgrading our plan to something faster. We currently get something like 8-10 Mbit/sec down and 128-256 Kbit/sec up, and we can allegedly upgrade to 20 Mbit/sec down and 2 Mbit/sec up. Trouble is, to do this Optus tell us we need to upgrade our modem. Currently we have a Motorola SB5101, which takes the coax cable in, and spits out a single Ethernet interface that goes into the WAN port on my OpenWRT Netgear WNDR3800 router, and just gives me a public IP address on the router. Below is the approved equipment list from Optus[1]: Manufacturer Model(s) ========================== Motorola SB4100, SB4101, SB4200, SB5100, SB5101 Netgear CG814WG, CVG824G, CG3000 CISCO EMTA2203, DPQ3212, DPQ3925 I note that my modem is already on there, but allegedly (second-hand information) the woman at Optus suggested a Netgear or a CISCO. So having reviewed a couple of the Netgear modems (on the basis thay they're almost certainly cheaper than the CISCOs), I've found that they've got a lot of router smarts in them, and have 4 LAN ports, WiFi, NAT, and all manner of other things that you want in a router, but that I don't want in a modem running proprietary software. I would like to be able to plug a modem's Ethernet port directly into my current router, and have *my* router do all the hard work of NATting and private addressing etc. Does anybody know if any of the modems listed above can do this, while supporting whatever new stuff is required to obtain the 20 Mbit/sec speeds being offered (I don't know enough about cable internet to understand what exactly needs upgrading)? 1. https://www.optus.com.au/shop/Broadband/Offers-&-Extras/Approved-Equipment-… -- Regards, Matthew Cengia

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remote list of changed files
by Russell Coker 22 Jan '13

22 Jan '13

Is there a way of getting rsync to just list what it would do without doing anything? Failing that is there any other way to get a list of changes between two trees of files where one of them is remote? I've got an archive of 30G+ of video files that needs to be synchronised occasionally with a system that has limited quota. I want to get a list of new/changed files that I can pass as parameters to tar and then take a tar file on a USB stick with the new files. I know I could run "find ." on both sides and then compare the output files, but I'd prefer something less hacky if possible. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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