Apr 292016
 

The InternetAnd here we go again… Wednesdays. Well, on Wednesday, 2016-05-04 my internet service provider will have to do some undefined maintenance again, and that’s supposed to be happening in between 01:00 – 06:00 am. According to my provider UPC, there will be several short periods of unavailability of service about 15 minutes long. Of course they’ll do everything as quickly and properly as possible as to not to interrupt their customers’ services too much – or so they say. So, once again:

Wed, 2016-05-04, 01:00 am – 06:00 am UTC+1 – Expect several short downtimes in that time frame!

Oh, and in case anyone noticed (nah, I know you didn’t…), sorry for that unannounced downtime on Thu, 2016-04-21. Should’ve been roughly from 03:00 pm – 07:00 pm UTC+1. This was done for two reasons:

  1. The WinSSL layer had broken down permanently (LsaSrv) due to a bug. When that happens, only a reboot can fix it. There is only one service relying on WinSSL instead of OpenSSL or GnuTLS, but it’s an important one that I do not wish to operate without a cryptography option, as it’s endangering the privacy of my users.
  2. The OS hard drive had shown signs of sectors becoming defective. This called for an analysis to see what areas of the file system had taken damage. Luckily, it only got some $I30 index files (deleted files still being referenced) and one unimportant IPCache.dat, which is just a local DNS cache file of a single service. Also, if the state would be recoverable, a full backup was in order.

So, the file system errors have been repaired, and defective blocks have been marked, restoring proper, consistent operation. Since the drive is no longer to be considered reliable enough, I decided to take the extra time to create a fresh full backup / system image of the operating systems’ and services’ current state, so when “C:” does die, I can restore without too much hassle. The last full backup was too old anyway, with a lot of important stuff already missing by now.

Got any flawlessly working U160/U320 68-pin SCSI drives >=36GB that you could part with? ;) If so, post in the comments, let me know how much you want for it. ;) And maybe don’t try to post in the time noted above. :)

Nov 202015
 

The InternetIn recent days, there sure are more maintenances scheduled for the DSL infrastructure in my town. So here’s another one: Next Wednesday (it seems it’s always Wednesdays), 2015-11-25 my server and all of its services including this weblog may go offline in between 00:00 a.m. UTC+1 and 06:00 a.m. UTC+1 for any arbitrary time. As usual, my ISP says “we’re going to work as fast as possible”, but you never know, right? So there you have it. Last time it lasted about an hour if I remember correctly, and the time before it was about as long as well. So I guess the downtime’s going to be in the same ballpark roughly. Let’s keep our fingers crossed and hope they don’t mess up my being hooked up to the correct DSLAM again…

Jul 022015
 

NetworkIt seems that two months after the last maintenance in May another one needs to be done on 2015-07-08 around 00:00 AM – 06:00 AM UTC+1. Again this means that all XIN.at services may see some downtime during this period, this weblog included. So no eMail server, no web server, no anything. By trend these maintenances tend to put me offline for short periods of time only, but who knows what UPCs gonna do. Just so you know.

Feb 062015
 

Network[1] Everybody hates servers going offline. Especially email servers. Or web servers. Or MY SERVER! Now I prepared for a lot of things with my home server, I prepared for power failures, storage failures, operating system kernel crashes, everything. I thought I can recover from almost any possible breakdown even remotely, all but one: My four bonded G.SHDSL lines all failing at once. Which is what just happened. After lots of calls and even a replacement Paradyne/Zhone SNE2040G-S network extender having been brought to me within the time allowed by my SLA, all four lines still remained dark.

Now, today the telecommunication company which is responsible for the national network fixed the issue in the local automatic exchange. I tried to find out what had happened exactly, but ran into walls there. My Internet provider UPC got no information feedback from the telecommunication company A1 either, or at least nothing besides “it’s been fixed at the digital exchange”. Plus, as I am not an A1 customer exactly, so they won’t answer me directly. The stack is: UPC (internet provider) <=> Kapsch (field technicians handling UPC branded Internet access hardware, via outsourcing by UPC) <=> A1 (field technicians regarding the whole telecommunications infrastructure), while UPC may also communicate with A1 directly to handle outages. Communication seems to be kept to a minimum though. :(

Bad thing is, for a “business class” line, an outage of almost two days or 47 hours is a bit extreme. In such a case, more efficient communication could easily fix it faster. But it is what it is, I guess. And now I have to send one of the two Paradyne/Zhone G.SHDSL extenders back to UPC, this little bugger here:

The actively cooled Zhone 2040 G.SHDSL extender

The actively cooled Zhone SNE2040G-S G.SHDSL extender (click to enlarge)

There is actually a HSDPA (3G) fallback option, which works by implementing an OSI layer 2 coupling between the G.SHDSL line and the 3G access, keeping all IP addresses and domains the same and the services reachable during times of complete DSL failure. But I won’t order that upgrade, because it’s a steep 39€ before tax per month, or 46.80€ after tax. That’s just too expensive on top of what that connection’s already draining from my wallet.

All in all, this greatly endangers my usual, self-imposed yearly service availability of >=99%. 47 hours is a lot after all. So to maintain 99%, the server cannot go offline for more than 3 days, 15 hours and 36 minutes per regular year, and now I already have 1 day and 23 hours on the clock, and it’s just the beginning of the year! Let’s hope it runs more smoothly for the rest of 2015.

[1] Logo image is © Kyle Wickert, Do You Really Understand The Applications Flowing Through Your Network?

Feb 152012
 

Internet LogoMy Internet provider UPC just informed me, that there will be some undefined maintainance work going on on the 29th of February, that’s exactly in two weeks from now. According to the announcement, the downtime might range from midnight to 06:00 AM. That means, that all XIN.at services including this website will be down between 00:00 AM – 06:00 AM on 2012-02-29. I hope we can expect everything to just work as expected after the maintainance is done. But you never know with Internet providers, not even when running a business-class line, so better be prepared for anything.

Services that will be down include, but are not limited to the XIN.at web server, mail server, FTP server, IRC server and other minor services like time serving etc. Since the work is being done at night, chances are that only very few people will even notice this. Let’s hope that it goes that way!