May 2013 - main - earth.li

[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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Why are some of my ports appearing in a port scan?
by steve-alug＠hst.me.uk 10 Jun '13

10 Jun '13

Hi folks. I'm confused. Every now and again, I use Shields UP! at grc.com to check that there's unexpectedly open ports on my system. I checked last night and I found 2 open ports, 5 closed ports and all the rest were "stealth" ports. The 2 open ports I was expecting. Stealth ports mean simply that they don't reply in any shape or form to the outside world. I expect, and usually get, all my ports except for the two open ones to appear as "stealthy". I don't understand why I'm now getting 5 closed ports showing up. I have a cable modem that's configured to do NAT for me. It has 3 port forwarding rules, each for single tcp ports. (One of these rules is outside the range usually scanned for by SheildsUp, that's why it's not included in the count of open ports) I don't forward any port ranges. I don't have a DMZ. UPnP is disabled. The ports that are appearing as closed are: 135, 137, 138, 139, 445 I turned off my server's smbd service and rescanned, and I got 135, 137, 138, 445 i.e. port 139 disappeared. So it does seem that services running on the server directly affect ports that are being shown as closed on the router, despite there being no port forwarding rule for them to get past the router onto the server. 135 DCOM Service Control Manager 137 NetBIOS Name Service 138 NETBIOS Datagram Service 139 NETBIOS Session Service 445 Microsoft Directory Services I've just used NetScan on my mobile, (whilst not connected to wifi), and scanning my public IP address I got two expected ports open, and also 80 HTTP 110 POP 143 Internet Message Access I tried with a different mobile app (Port Scan) and I got 1 of the expected ports listed as open, and 80 HTTP 110 POP 143 Internet Message Access 8080 Alternate HTTP I tried with an on-line port scanner, http://nmap.online-domain-tools.com/, and I got only the two expected ports open. I've just tried rerunning GRC's Shields up and now it reports the two expected open ports and also just 137 and 138 as closed. I'm rather confused as to what's going on. Anyone got any ideas? Regards Steve

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More ftp
by Anthony Anson 05 Jun '13

05 Jun '13

Support@ asks: > Do you know what your public IP address is? Do you have a fixed IP > address? I'm in the Tea House in Naardge, so haven't access to my hard copy crib(s) - I don't *think* my IP address is fixed, BICBW. I can't discover anything on this box (MSi Wind Notebook running Mint) which will tell me - I'm sure there is, but I've never had to look. Can I ask the terminal, and if I can, what would the magic formula be? (Pretty please...) -- Tony http://www.girolle.co.uk/

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O/T Uninstalling Linux and making Windows boot again
by steve-ALUG＠hst.me.uk 02 Jun '13

02 Jun '13

Hi geniuses :-) I have a laptop that I purchased with Windows XP installed on it. I installed Ubuntu on it, and then migrated that to Lubuntu, but there's still Windows on a partition of it's own, and it still boots. I'm thinking about giving this machine to my kid who doesn't need linux, just windows. Is it possible to uninstall Linux and get the copy of Windows to boot correctly again. The problem is I don't have the windows install disk, so I'm reliant on any windows programs that may be installed on the disk, or any genuine tools that may help - I don't want to download a dodgy copy of Windows to do it! Afaik, if I just format the linux partitions, it will remove most of the initial boot loader, and then it won't boot windows any more. I'm using Grub btw - the old version (V1.??) Has anyone done this before or have any ideas? Cheers Steve

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RAID discs
by Chris Walker 31 May '13

31 May '13

Having seen that others are suffering RAID problems, perhaps now is an opportune time to ask about mine. I have an Edimax enclosure with 2 x 1TB discs in it. I got a notification from it yesterday to say that sdb had either failed or would fail within the next 24 hours. The drives were bought at the same time as the enclosure so given that one is failing or has failed, is it wise for me to replace both? The discs in there at the moment are Seagate drives and I don't think I specified anything special for them i.e. I just bought 2 discs. This time I'm going to go for something like a WD Red drive which are specified for NAS use. So 2 questions. Does anybody have any recommendations for discs or are the Western Digital discs ok? And second, should I replace both or is one ok for the time being?

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ftp problems
by Anthony Anson 31 May '13

31 May '13

Using up-to-date Mint, and happily using Fire FTP. Suddenly, half the page vanishes, leaving me with just the local side and a 'send' arrow. I can navigate through the local directories. Can't restore Fire FTP it to its proper configuration (AFAICS), so have been using Filezilla, mainly successfully - but - from time to time it connects, but the remote site spits my shaking-hand out. Status: Waiting to retry... Status: Connecting to ###.###.###.#:21... Status: Connection established, waiting for welcome message... Response: 438 Access denied. Please contact your support. Error: Could not connect to server (The :21... is kindly supplied by remote server, and should show there. It's a Linux server BTW.) Contacted Support and in the morning received two e-mails, just after I'd successfully ftpeed the file I tried to put up the evening before. No change in user, password or remote address data. Support has no idea why it wouldn't work the previous evening. *Could* the server be too busy, and <rhetoric> if so, couldn't it say so </rhetoric>? Any idea what 438 is? (I don't want to use a search injun using this dongle on GPRS unless I really have to...) -- Tony http://www.girolle.co.uk/

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Compaq Proliant servers going free
by mick 29 May '13

29 May '13

I'm not sure how many freeglers there are on this list, but I thought I'd pass this on anyway. "THREE complete Compaq PROLIANT 8500R servers offered in Eaton: http://norfolkfreegle.org/Post/ViewPost/13591" Mick --------------------------------------------------------------------- blog: baldric.net gpg fingerprint: FC23 3338 F664 5E66 876B 72C0 0A1F E60B 5BAD D312 ---------------------------------------------------------------------

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Software RAID error
by Mark Rogers 29 May '13

29 May '13

I'm having problems understanding what is happening on my RAID array. $ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid1 sda1[0] sdb1[1](F) 976629568 blocks super 1.2 [2/1] [U_] To me, that suggests that sdb has failed, however, syslog contains lots of errors on sda but no mention of sdb. Amongst the things I've learned this morning, is the fact that I'm not getting any notifications; this only came to light because a VM that is hosted on this RAID array has lost the ability to write to one of its virtual disks (but not all of them). Should I conclude that both disks have failed? What is the best route to recovery here? Ie which disk do I swap out first with a new disk? Logically swapping out sda is the only thing that makes sense to me but advice welcomed. smartctl reports that neither disk had SMART enabled, which is odd because I thought they had, so there's no information there. I have enabled it this morning but don't want to try doing self-tests at this stage unless someone more knowledgeable than me says I should. 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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Re: [ALUG] how to block new connections whilst allowing existing established
by mick 27 May '13

27 May '13

On Sun, 26 May 2013 20:34:24 +0100 Adam Bower <adam(a)thebowery.co.uk> allegedly wrote: > On Sun, May 26, 2013 at 08:09:07PM +0100, mick wrote: > > > > Before I start playing in earnest, does anyone know of a more > > elegant solution? > > Have you looked at profiling the connection length and how the client > works? I work for a CDN and to be honest since we acquired a > particular customer the scenario changed from us having a traffic > pattern that when taking a node out of our delivery group after 2 > hours it would see no connections, since this new customer even after > removing a node from delivery it will still see significant amounts > of traffic after 24 hours. > > The way we deal with it is to let some customers get "unlucky" but > then given the client immediately does a new dns lookup and goes to a > new server it means the interruption to them would be very brief. > > Anyhow, you might want to look at some kind of load balancer like > varnish for this scenario as if not a stuck connection might mean your > reboot never happens. > > Also, see if the clients can support range headers, if so they can > resume the download from the missing bit. This means it's not the end > of the world when a download fails. > Adam Thanks for this. But I should have said that my mirrors are on VMs in datacentres I don't control. So I have no chance of sticking a load balancing proxy in front of the servers. Furthermore, the "customers" are not paying me anything (I give the mirrors to the community) so I have no form of communication with them. I /could/ just be brutal, but I don't want to be - and as you will see from my answer to Nev, it turns out I don't have to be either. Cheers Mick --------------------------------------------------------------------- blog: baldric.net gpg fingerprint: FC23 3338 F664 5E66 876B 72C0 0A1F E60B 5BAD D312 ---------------------------------------------------------------------

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how to block new connections whilst allowing existing established
by mick 27 May '13

27 May '13

Hi guys I run a couple of mirrors serving "tails" over http. Occasionally I need to shut those servers down and reboot (for example I have just upgraded both of them to wheezy). Both servers are reasonably busy (they ship out about 2-3 TiB each per month) and normally have active connections at the time I want to power cycle them. Connections can (of course) come from anywhere and some people may be on slow lines and may be over half way through a download of one of the 700 meg iso files. If I simply power cycle the server they will likely lose the connection and the download. I'd like to be more friendly than that. So what I have in mind is some mechanism that I can invoke to prevent new connections being established but permit the existing ones to complete before I switch off. I've thought about cobbling together an iptables script which will change the lines: BLAH –dport 80 -m state –state NEW,ESTABLISHED -j ACCEPT to BLAH –dport 80 -m state –state ESTABLISHED -j ACCEPT temporarily and then switch it back afterwards. But I have yet to try it. Before I start playing in earnest, does anyone know of a more elegant solution? TIA Mick --------------------------------------------------------------------- blog: baldric.net gpg fingerprint: FC23 3338 F664 5E66 876B 72C0 0A1F E60B 5BAD D312 ---------------------------------------------------------------------

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