Category Archives: Uncategorized

Syncthing: breaking upgrades

Syncthing is usually very easy to upgrade: it upgrades itself silently or via apt-get. Problem is, when it changes version (lastly from 0.12 to 0.13) it is not compatible anymore. It is not a big problem since it is easy to upgrade, but you kind of have to upgrade your entire Syncthing cluster at the same time, otherwise you get an undesired fork.

This was the quite confusing error message i got on the newly updated system that failed to connect to non upgraded systems:

[THC2C] 19:17:52 INFO: Failed to exchange Hello messages with <ID> (<ADDRESS>): EOF

So, be mindful when upgrading syncthing so you dont get a non breaking upgrade when you dont have time to upgrade everything.

Syncthing on Android

I installed Syncthing a few weeks ago. Now I found it was time to connect my Android mobile to it. Installing Syncthing via Google Play was easy. Configuring it, not that easy. The amount of useful error messages… close to zero.

I found:

  1. When I manually write the address to my other syncthing unit (like my NAS), only IP address works (with :port after it). Writing a domain name fails.
  2. When sharing a folder, I can not share a folder on the SD card: I get something like “Error (100%)”. To me, this is a pity, because I could put a big SD card (32-64GB) and have synchronised music there… but it seems not possible.

Update 2015-11-14: Upgraded to new syncthing version (0.12.2). Syncthing (for Android) now does not start properly. It just keeps “Loading”. No error message. No way to interact with it.

Lighttpd, Debian and CGI

I installed lighttpd in Debian (Jessie), and I wanted CGI to work.

The Welcome/Placeholder page has some information, and part of it is:
CGI scripts are looked for in /usr/lib/cgi-bin, which is where Debian packages will place their scripts. You can enable cgi module by using command “lighty-enable-mod cgi”.

This appears to just not be true. CGI-programs worked perfectly when placed /var/www/html/cgi-bin, but not in /usr/lib/cgi-bin (or /var/www/cgi-bin). This is with default configuration.

Upgrading ownCloud 7.0.4 to 8.1.1

I am running ownCloud on a Debian machine with Mysql and I have been a little behind with upgrading it. Today I upgraded from 7.0.4 to 8.1.1 following the standard instructions. A few more notes on my environment:

  1. I don’t use encryption for files
  2. I don’t use https/ssl (I am behind an openvpn server)
  3. I did the upgrade in one step (7.0.4 to 8.1.1, not via intermediate versions)

It basically went fine. When I ran:

$ sudo -u www-data php occ upgrade
ownCloud or one of the apps require upgrade - only a limited number of commands are available
Checked database schema update
Checked database schema update for apps
Updated database
Disabled 3rd-party app: calendar
Disabled 3rd-party app: contacts
Disabled 3rd-party app: documents
Updating  ...
Updated  to 0.7
Updating  ...
Updated  to 0.6
Updating  ...
Updated  to 1.1.10
Updating  ...
Updated  to 2.0.1
Updating  ...
Updated  to 0.6.2
Updating  ...
Updated  to 0.6.3
Updating  ...
Updated  to 0.6.0
Update 3rd-party app: calendar
Exception: App does not provide an info.xml file
Update failed
Maintenance mode is kept active

I am a little surprised, because I don’t remember calendar, contacts and documents being 3rd party apps before (?). Anyway, the server did not come up, so I ran the command again:

$ sudo -u www-data php occ upgrade
ownCloud or one of the apps require upgrade - only a limited number of commands are available
Turned on maintenance mode
Checked database schema update
Checked database schema update for apps
Updated database
Update successful
Turned off maintenance mode

Now it worked. Logged in, no traces of the three 3rd-party apps. Whatever, I use ownCloud for the files.

Performance after upgrade
ownCloud is not particularly fast. I did a very quick and unscientific performance check: before upgrading I uploaded a folder (17 files, 4.1 MB) to ownCloud: it took 30 seconds (for the desktop client to complete syncing). After the upgrade the same folder took 19 seconds to sync. This proves nothing of course, but at least it seems promising.

Ubuntu Client
My Ubuntu client used ownCloud vs 1.7. It does not work with 8.1.1. Installing ownCloud client from external repository worked fine. Same thing for Debian, obviously.

Eee701 in 2015

My eee701 is not doing very much anymore, but sometimes it is handy to have it around. I have not upgraded it since Lubuntu 13.10, and that version is not supported anymore. I found that:

  1. Since 13.10 is abandoned upgrading with apt-get generated errors.
  2. 15.04 Lubuntu desktop ISO complains that the hard drive is less than 4.1Gb.
  3. 14.04.2 Lubuntu desktop ISO complains that the hard drive is less than 4.5Gb.

Thus, the standard upgrade or installation paths were blocked. And I was not very interested in putting lots of effort into getting my eee701 running a current system.

Instead, i tried the Ubuntu mini-iso. That was very nice! The iso itself is written with dd (rather than the Startup Disk Creator) to USB drive. The installation is text (curses) based, but very guided (just like Debian). I choose a single 4GB ext4 partition for root, no swap (since I have 2GB RAM) and “Xubuntu minimal” desktop. Keyboard, Wifi and timezones were all correctly set up. When installation was complete and system restarted I had 1.8Gb used and 1.7Gb available. Not even a web browser was installed, but Xubuntu itself was fine.

Not bad at all!

Seeding Xubuntu and Lubuntu

It is not much I do to contribute to the Ubuntu community so when Ubuntu 15.04 was released a few weeks ago I downloaded 4 isos with bittorrent and kept seeding them for the benefit of Ubuntu users.

Now (2015-05-10):

Image                                Size     Ratio
lubuntu-15.04-desktop-i386.iso      696Mb       120
lubuntu-15.04-desktop-amd64.iso     690Mb      60.0
xubuntu-15.04-desktop-i386.iso      970Mb      68.5
xubuntu-15.04-desktop-amd64.iso     963Mb      68.2

Does this mean anything?

If the ratio has anything to do with the popularity of different ubuntu versions:

  1. It surprised my that Lubuntu is so popular
  2. It surprised me that i386 is still very popular

There are, however, a number of factors that could disturb the correlation between my ratio and the true popularity of different Ubuntu flavours:

  • The way Lubuntu vs Xubuntu push people to the torrent (rather than the direct http/ftp) download, I found it harder to find the Lubuntu torrent, though.
  • Lubuntu and Xubuntu may have different audiences, with different attitude to torrent downloads.
  • i386 and amd86 may have different audiences as well
  • If more downloaders mean more seeders, and people on average seed close to 1.0 (or even above) then my Ratio may mean very little.
  • The tracker may have identified me as a stable seeder and sent downloaders of less popular images (both to download and seed) my way, in an attempt to provide equally good service for everyone (no idea if trackers do this).

The i386-heaviness of Lubuntu indicates that there should be correlation between general popularity and my Ratio.

Visiting USA easy with ESTA

Since 9/11 it has become more and more inconvenient to visit USA has been my personal experience. Now, having to apply for an ESTA in advance, and pay $14 for it, despite it is not at all a VISA did not make me happy.

I just came home from New York, flying there with British Airways, via Heathrow. I must say that visiting USA has not been easier and less bureaucratic in a long time. ESTA replaces the green paper form in a simple way.

I needed to:

  1. Apply for the ESTA online in advance, pay $14, authorizatized immediately
  2. A few days before travelling, give some personal information to British Airways online
  3. Show my passport in Heathrow, and answering Yes to the question “do you travel on ESTA?”
  4. Show my passport in JFK, saying I am there on vacation
  5. Fill in the customs form that everybody entering USA has to hand in
  6. Just show my passport when leaving USA

What i did not have to do (which has happened before ESTA) was:

  • Being interviewed in EU airport by USA security personell
  • Extra/separate security check for USA flights in EU airport
  • Fill out the green form and hand over to US immigration
  • Keep, and upon leaving USA hand in, the little green paper from the green form, that used to be stamped to passport

From an integrity point of view, ESTA may be questionable. And paying $14 is more expensive than $0 which used to be the Visa Waiver program price. But, I like to be able to travel with just my passport, and not doing paperwork on the way. At no point I needed to show the printout of my ESTA authorization or otherwise give away my ESTA authorization number or anything.

This is of course just my personal experience from one single trip.

New York, as always, was fantastic. I recommend getting up in the Rockefeller Center “top of the rock” rather than Empire State Building. The view is better because you can walk around on a platform where you get an almost 360 degree view instead of having to walk around the whole building. Queues were much shorter (basically none at all). You can see both Empire State building and all of Central park from Rockefeller Center (you dont want to photograph Rockefeller Center from Empire State Building). If you smuggle a small tripod up to Rockefeller Center and use it descretely you can take amazing night pictures from there.