but I ve already forseen the unwanted meet for some time . My elder daughter does need to run educational software from school. And my wife wants to run education software for our younger son. And making all that running under different emulation environments does eat my time, and result is not always good. And also children start to want games Issue 1. Need hardware to run more or less modern windows on. For last 6 years, my home network consists of a more or less powerful headless server, and 3 terminals to access that. Terminals are definitely too weak for windows. And server is needed in 24/7 mode so sorry no windows there. Likely solution for this is one of 3 terminals is actually dying (it is doing so already for months but still works, just hangs sometimes) and needs a replacement, so I can just replace it now and use more powerful hardware. Issue 2. Windows host or windows VM? While windows VM feels preferable for a such a deep-linux person as myself, I tend to think that dual-boot host is better here. If the very reason of allowing windows into this house is make it easy to install and run random windows software, then doing so in VM environment is explicitly against the goal. Issue 3. Use unlicensed windows or buy a license? Although absolute majority of windows users here is Russia use unlicensed windows, it is somewhat unfair to promote free software and use unlicensed windows at the same time. And windows home basic license is not that expensive after all. The setup that makes me less uncomfortable than others is:
- obtain powerful enough hardware, and install that instead of failing terminal,
- obtain windows 7 home basic license
- install dual boot linux + windows, and under linux install windows VM
- when needed, try windows VM first, and in case of any issues, immediately reboot into windows host. What I can t find out for some time already is does microsoft retail license allow to have both host and VM installation on the same computer? These will be physically different installations, but on the same computer, and will never run at the same time. License wording does not give exact answer on this. I wanted to ask on Microsoft s support forum but failed to register there. After asking me quite a few things it claimed that there is some temporary problem and suggested to retry later. I retried later and got the same. I then asked here but looks like nobody knows. At least I want to know, what will happen if I will try to activate windows in VM after I ve activated windows (with the same key) on host. Will this render both installations non-genuine ? Also I d appreciate any comments on the whole situation

For years, I ve been using Jabber for all my IM needs. There is a private jabber server here, it runs several transports, so there was no problem to keep connectivity with people. until recent. Looks like now everybody is moving to skype. Quite a few of my contacts no longer use anything else. This is starting to cause problems. I feel quite discomfortable about moving to proprietary software that is a questionable quality (1) implementation of a secret protocol. But pressure increases: staying away from skype already does cause difficulties. (1) After recent unclean shutdown of server that hosts desktop sessions for thin clients here, quite a few users have been unable to login to Skype without erasing entire ~/.Skype directory. And there is no working jabber transport for skype. Bad. I m aware that some multi-protocol IM clients can talk skype via api provided by official skype client. This is better than nothing, but still uncomfortable.

When trying to upload a several-gigabyte file over a slow link using rsync, don t forget to use inplace! If you don t, result could be that connection breaks after 15 hours, and transferred part of the file is not there

Situation: a home Debian-based desktop, used by non-technical family members, without any lock-screen passwords or so to maximize convenience. Need: without making much noise, hide private files from too curious relatives. Solution: aptitude install cryptkeeper.

Looks like installing iceweasel backport packages from

deb http://mozilla.debian.net squeeze-backports iceweasel-release

causes installation of backport of libcairo2 1.10 which breaks printing from GIMP, as described in this ubuntu bug. Does anybody know a fix/workaround? Update: looks like running gimp with LD_LIBRARY_PATH set to directory containing library files from squeeze libcairo2 package (1.8.10-6) workarounds this. But this story makes me think again that bundling libraries with applications is not that bad idea at least for users who need to get things done.

NoSpamNX and OpenID wordpress plugins don t work properly with each other. Sorry people for calling you spammers, and many thanks for your comments. I ve manually approved everything that NoSpamNX incorrectly filtered, and disabled NoSpamNX for now. Will look for a good replacement.

Since post about lost n900 was on the top of this blog for almost a year, I should probably write a few words about what was next. Since I do need mobile phone every day, I had to get some replacement quickly. Given Maemo was dead and Meego device not available, I decided to go Android. Since after n900 hardware keyboard became a must for me, I decided to try HTC Desire Z. That device made me angry every day, both because of hardware (what a silly idea to place volume buttons such that they are below hardware keyboard when it s opened? they got pressed almost every time when I used keyboard!) and Android itself. I think quite a few things are broken in Android, but most annoying is broken multitasking. I can t live with dialog elements content get lost when I switch to other app and back. Please don t tell me that it s app fault: maybe technically it is, however too many apps have it so I have to generalize. I will likely write more about this later. At the same time, exciting things have been happening in Maemo community. It was the time when Community SSU raised, also several mapping applications went out of dark, and more. I was still subscribed to Maemo resources so I read about all that and got more and more frustrated with my new Android device. And on one sunday evening, after reading more exciting news from Maemo side, I decided that enough is enough. And ordered a new n900. Few days later, I ve sold HTC for about 80% of it s original price. That was an emotional solution, and of course it could not play well in the long term. Despite of individual exciting news, Maemo community was becoming weaker. Device itself had major usability issues (e.g. it could occasionally unlock while being in my pocket, and call a random number from address book and I have quite a few addresses abroad so such calls not only bother people, but also are expensive). There was not many applications, and those available had problems. There was a visible difference between my friends who could just take a phone and quickly do something, and myself who had to struggle with incomplete and buggy software. Also skype quality was very bad. Also when I was planning a 2-week trip to location without mobile network, I tried to preload map of planned route, but it preloaded only part and I was unable to make it preload the rest. Also many similar issues. So it became clear that if I want usability, I have to go to a standard platform. And as such, Android still is the only option. I searched for a device that runs more or less modern Android version, has hardware keyboard, and is not HTC Desire Z. There was not much to choose from. I ordered SonyEricsson sk17i. I m already using it for about 4 months. For common use cases, such as locating a business nearby, or routing to a given address, or quickly browsing a web page, it works. However, all Android flaws including broken multitasking and no-undo-in-text-fields are here, causing everyday frustration. My conclusion is that no smartphone-like devices without major usability issues are available today. What is available probably could be used to somehow satisfy immediate communication needs, but nothing above that. Bells and whistles are there, but I m not interested in those. I want a linux-based pocket-sized mobile computer that will handle both my communication needs and other interests. That could be hacked when I want to, but just works at the rest of time. Something like my Debian desktop. Openmoko was a big hope but it failed. Maemo was a big hope but incompetence of Nokia killed it. Meego was dead before it was born. There is still some life around several mobile linux projects (GTA04, Maemo, Meego, some others), but hopes for it to grow into something that could be used without huge hacking are little.

There are probably many ways. But this one looks pretty simple and takes seconds.

git add . && git commit -m "backup-$(date +%Y%m%d-%H%M)" && git reset HEAD^
After this command, nothing is changed in working tree or in branch history. But reflog gets a reference to the current tree content, which could be extracted (git help reflog) if you suddenly realize that you ve messed things up. Con s: depends on proper .gitignore to avoid garbage in repository; can t be used if there is something valuable in the staging area; reflog has limited lifetime, decreased even more by large rebases

Long time has passed since last entry in this blog. Moderation panel is full of spam comments. It s still unclear if I will ever will continue it. However, given what is happening in my country these days, I *must* write at least one entry, just to put a number there. 632305222316434 Everyone who disagrees with criminal behaviour of Russian president, government and all those rascals, must do that.

This is a wonderful beginning of the week. I ve lost my n900. Most likely, case was not properly mounted on my belt today, and fell down at some point. Chance to get device back is near-zero. It does not respond to calls to itself ( off or out of network coverage ) so likely somebody found it, and turned it off and/or replaced SIM, etc. I ve used it for more than a year. It had lots of customizations, large chat logs, and lots of other data. And it was tightly integrated into my day-to-day life.
Some backups are available but not very recent. And not sure that these backups could be used to recover things into other device and, given all those recent news about Nokia, it is definitely unwise to buy a new n900, as well as any other Nokia device. This blog will unlikely get any more n900-related posts. I m quite frustrated, and can t do anything useful already for several hours .

This post is for those who want to upgrade their debian to the shiny new release, but still wants to continue using KDE3 packages from lenny. This could be done by keeping lenny as a low-priority apt source, and proper package pinning. To keep system more consistent, I use the following rule: pin to lenny all packages from sources that build something depended on KDE libraries. This rule catches all of KDE3, and also everything that uses KDE3 libraries, but was not included into KDE3. Also, this keeps good practice of avoiding installation binary packages built from different versions of the same source package. One exception is OpenOffice.org. Due to it s KDE plugin, it is caught by the rule. But lenny has too old version of it. Better to take version from lenny-backports. Below is my script that generates needed configuration. It parses /var/lib/apt/lists/*_lenny_*_Packages files; to have these, lenny should be mentioned by name (not by oldstable alias) in /etc/apt/sources.list. Packages found are pinned with priority of 900 (this value may need to be adjusted). Output of the script could be put directly into a file in /etc/apt/preferences.d/ directory before upgrading system to squeeze.

#!/bin/bash
# Find out sources that build packages depending on kdelibs4c2a, and pin
# to lenny any package that comes from any of those sources.
# Exception is openoffice.org - pin it to lenny-backports instead
cat /var/lib/apt/lists/*_lenny_*_Packages   awk '
        BEGIN  
                found["kdelibs"] = 1
         
        /^Package: /  p=$2; s=$2 
        /^Source: /   s=$2 
        /^Depends:.*\<kdelibs4c2a\>/  found[s]=1 
        /^$/  allp[p]=1; p2s[p]=s 
        END  
                delete found["openoffice.org"]
                for (p in allp)  
                        if (p2s[p] in found)  
                                print("Package: " p)
                                print("Pin: release n=lenny")
                                print("Pin-Priority: 900")
                                print("")
                         
                 
         
'
cat /var/lib/apt/lists/*_lenny-backports_*Packages   awk '
        /^Package: /  p=$2; s=$2 
        /^Source: /   s=$2 
        /^$/ && s=="openoffice.org"  
                print("Package: " p)
                print("Pin: release n=lenny-backports")
                print("Pin-Priority: 900")
                print("")
         
'

Trinity project in an attempt to keep KDE3 desktop compatible with ongoing changes elsewhere, and to some extent to fix bugs and add features into KDE3. It is for those us long-time KDE users who is upset by the way that KDE has chosen for KDE4. Unfortunately Trinity project looks small and underpowered, so it s future is unclear. Did not try it yet. There are debs, although some people think that it is hard to deal with those, because of KDE3 package namespace now used by KDE4, and also because of binary compatibility issues within Trinity. Why I don t like KDE4? Because I have no interest in eye candy, but due to heavy use of thin clients with apps running on remote server I do care about desktop resource consumption. A medium-class server (2 dual-core 2 GHz cpus, 16G ram) perfectly hosts 50 KDE3 sessions, served over vnc. Anything near to that with KDE4? I m not aware of any good-working kde4-over-vnc-over-network configuration, even for a single user over unloaded network. Looks like within KDE4, even with all effects turned off, every tiny operation results into near-fullscreen update. Spice is promising but requires per-session VMs which is a serious drawback when number of users is high.

Recently I tried once more to read a pdf file on n900. And as usual, it worked bad. Not only because of small screen that particular pdf had two-column formatting, and n900 s screen is wide enough to display one of these two columns with a readable font. Much worse was extremely slow redrawing. Finger scrolling on a touch screen is cool but only if system has enough power to immediately show content as it is scrolled to be visible. In practice I try to scroll with finger, then a second or two pass, then page on the screen starts to move, replaying all my finger movement during that second or two (which was not very direct because of no quick visual feedback), by the way text at borders goes out of screen for a moment, and that area becomes broken and is redrawn only after several more seconds. And then, in less than a minute (after reading displayed content), all that has to be repeated. In total, this makes UI almost unusable. While looking at this, I thought why not use GPU here? This device has a powerful GPU, enough even for non-trivial games. So why not convert a pdf page into a scene description for GPU, and then get zero-delay scrolling and scaling at least? This could be useful even on desktops sometimes pdf viewers do have interactivity problems, especially at very-large scale (400% or more) which is needed to view board schematics diagrams. Anyone ever implemented this? Or maybe wants to implement?..

While browsing n900 FAQ (in Russian) on maemoworld.ru site, I ve found some hints on avoiding automatic package list update over gprs. Problem is that gprs here in Russia is relatively expensive, and downloading several-megabytes package lists at unexpected moments costs money that users don t want to pay. Of course, Nokia ignores this problem. Hints linked above may be useful. But actually those don t disable updates over gprs, but disable updates completely, which is inconvenient. Much better is to still have automatic updates when on WiFi connection. Fortunately it is very easy to get that. Just create /etc/network/if-up.d/zz_block_apt_over_gprs with following content:

#!/bin/sh
# If on GPRS, set fake apt proxy to stop automatic update from working.
# Otherwise, remove fake apt proxy.
if [ "GPRS" = "$ICD_CONNECTION_TYPE" ]; then
  echo 'Acquire::http::Proxy "http://127.0.0.1:8768";' > /etc/apt/apt.conf.d/zz-fake-proxy
else
  rm -f /etc/apt/apt.conf.d/zz-fake-proxy
fi
exit 0

Well, this actually also disables package installation while on gprs. Bit IMO this is not usually needed, and if you happen to need to install something over gprs, you may just remove /etc/apt/apt.conf.d/zz-fake-proxy

I have a Samsung CLP-315 printer. It works will with CUPS and foo2qpdl driver. Just ignore all the anti-distro junk written at driver s homepage, run aptitude install foo2zjs, and enjoy working printer on consistent system. But since the beginning there was a strange problem printing worked from everywhere, but not from iceweasel. If tried to print from the browser, error page was printed instead. So had to print to a pdf file, open it in kpdf, and print from there. Working but annoying. At last decided to do something with this. A quick search shows that problem is known, is not new, and as such has little chance to be quickly resolved. But then I found this hint. I immediately checked paper size in iceweasel s print dialog and yes, it was Letter! But the setting was greyed out, so unchangeable I ve tried to play with about:config (searching for print there), then tried to remove all printer setup from prefs.js no result, still Letter without option to change. But a web search helped again. Someone pointed that iceweasel has a separate menu item for page setup, at File::Page setup! That is where paper size has to be configured, tab within print dialog does not work! Mozilla people are wonderful UI designers. Many thanks to them for months of non-working printing. I ve told myself zillion of times that I should perform active steps to get rid of bugs on computers I use search the web for solutions, report bugs, fix code myself if nothing helps. That s the very point of using free software, after all. But still laziness lack of free time random real-life issues make me not to do so too often. So also many thanks to myself for months of non-working printing. But now printing from browser works, and that s good news . Update: full thanks above should be directed to, in order:

• Samsung firmware developers, who coded firmware that, when printing error page (btw wasting paper and toner), doesn t print what is actually wrong (paper size mismatch),
• Mozilla developers, who don t read default paper parameters from CUPS, but instead use own broken scheme,
• myself, for living with problem and not looking for solution for months,
• foo2qpdl upstream, who, by his anti-distro junk, turns people looking for solutions into wrong direction,
• Mozilla developers, who use braindead page setup UI.

And real thanks to the person (link above) for the hint about page size in applications that are unable to print

To get different page headers on different parts of document, one needs to set different page styles. To set page style for a page, one needs to double-click on new style name in page style list window, while cursor is inside the page. And surprise that changes style of all pages, not single page! So what about different page headers?.. Solution here. In fact this behaviour is somewhat logical. Unless there are explicit page breaks, the split of document into pages is not stable it changes while document is being edited. So applying a custom style to what currently is a page is actually an invalid operation. It is valid only for the first page after a break. Style for next page is defined in appropriate field of the style for previous page.

After aptitude or similar upgrade tool completes its job, new versions of files are installed into filesystem. However, some running processes may be still using old files (and actually Linux file systems continue to store invisible copies of old files while those are mapped by running processes). In case of a security update, having old versions running keeps system vulnerable even after update completes, which is not good. A reboot is possible, but that s an ugly solution. Fortunately tools exist to find processes that have deleted files mapped. One of these tools is checkrestart (from debian-goodies package). Just run checkrestart -p after upgrade, and you will see what to restart to be safe and even what init.d scripts to run with restart argument. P.S.
On a server with hundreds of running processes, checkrestart -p is terribly slow, likely because it makes separate queries to dpkg about files mapped by each process. Perhaps it could be seriously accelerated if first all names to query are gathered, and then each name is queried only once. Any volunteers to do that?

With help of LWN site, I ve discovered in-progress effort of writing a serious book about parallel programming, in form of a real open-source project where people can contribute. Book is titled Is Parallel Programming Hard, And, If So, What Can You Do About It?, edited by Paul E. McKenney. It is still far from being complete, but even in current state it definitely is a recommended reading. Many things are explained using Linux kernel code and environment. So it is also a good kernel resource. As for project things are managed in git repository, with commits from several people. Book sources are in TeX.

Just install and activate RusToLat plugin, and automatically get transliterated %postname% in permalinks for russian titles. P.S.
This blog is still english-only, but this is going to change

Older versions of Psi jabber client required manual changing status to online to leave auto-offline state. It was very handy for me: I connect to my jabber account from two locations (from home and from office), so after I left one of these locations, auto-offline soon happened, and Psi at that location did not return online until I returned and manually instructed it to re-login. Unfortunately newer versions of Psi (I guess, starting from commit 4a54500c on git://git.psi-im.org/psi.git, which was between 0.11 and 0.12 releases), and also Psi+, behave differently: if user activity is detected on the desktop, auto-offline state is left, and status becomes online again similar to leaving auto-away and auto-xa states. This change is not good for me, at least in two situations:

• vnc connection to home from office or to office from home I use this fairy often,
• occasional use of my home session by my wife for quick web browsing or similar.

In both these situations, Psi client not at my current location becomes online, which can cause routing incoming messages to wrong location. I don t state that new behaviour is somehow worse than old behaviour. But for my use cases, I want to get old behaviour back. I ve done some code reading. I think that point to fix is near the bottom of PsiAccount::secondsIdle() method, where any auto status is disabled if no timeout condition currently exists. This should be changed so that auto-offline state won t be left if some config key is set. I will try to implement this change soon (or at least I hope I will try ) P.S.
To make things even better, a check of some external condition could be performed to decide if client should return online from auto-offline or not. Then fancy things could be set up, e.g. return to online at office only if my mobile phone is currently registered in the office wifi network not really required but cool.