Autarchy of the Private Cave

Assumptions:

• current HDD is /dev/sda, it has a GPT (with bios_grub being /dev/sda1), separate /boot partition (/dev/sda2), and a physical LVM volume (/dev/sda3), where LVM holds all the remaining partitions (root, /home, /srv, …); LVM is properly configured, and system reboots with no problems
• your new drive is /dev/sdb, it is identical to /dev/sda, and it comes empty from the manufacturer (this is important! wipe the drive if it is not empty, especially if it used to be a part of another RAID)
• your system is Debian or Debian-based; in this exact example I’ve been using Ubuntu Server 10.04
• your LVM volume group is named vg0
• make sure you understand what each command does before executing it
• you do have an external backup of all your important data, and you do understand that the following operations are potentially dangerous to your data integrity

Inspired by: Debian Etch RAID guide, serverfault question.
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rtorrent is an excellent ncurses rtorrent client.

There are a few highly-popular patches, which haven’t yet made it into the Squeeze’s rtorrent version 0.8.6.

Note: ArchLinux already has an rtorrent-extended package, so you may want to look at that one (instead of my Debian package below). I might use Arch’s patchset next time to generate a truly extended rtorrent package.

I’ve incorporated 3 of such patches (#239 ipfilter, #2064 GeoIP support, and #2171 colours/eyecandy), and built a squeeze amd64 rtorrent-enhanced package.

A few excerpts to explain how these extra features are to be configured and used (all come from the above-mentioned trac tickets, some were edited/extended).

ipfilter

ipfilter allows to selectively blacklist/whitelist peers – based on IP address range files (so-called ipfilter files). The ipfilter files may, for example, come from bluetack.co.uk. Each line of the file contains a record in this format: range_description:start_IP-end_IP, where start_IP should be less than or equal to end_IP. Multiple files can be used. Overlapping ranges are merged automatically. Both incoming and outgoing connections are checked against the filter. Exclusions are not supported, so connection to/from IPs in all the loaded ranges will be disallowed and dropped.

Include “ip_filter=” directive in .rtorrent.rc. For example (paths are specified relative to user’s home directory):
ip_filter=ipfilter/level1,ipfilter/level2

It is probably a good idea to reload ipfilter files once in a while, so you can also include “reload_ip_filter” directive on schedule to refresh the filter. The same files named in “ip_filter” will be reloaded.

schedule = filter,18:30:00,24:00:00,reload_ip_filter=

To support the feature you may want to setup cron job to reload and unzip files from bluetack. Examples here and here.

GeoIP

In the Peers view of each torrent a new column – CC, country code – is added, which shows peer’s country code. When examining each peer, you will see more data from the GeoIP database (if you have the relevant files installed): AS num and city. At the very least, you need to have geoip-database installed. You can get free “lite” versions of city/AS-databases, rename them (removing “lite”) and put into an appropriate location to make rtorrent+geoip use them as well. Geop-isp data support isn’t integrated into this rtorrent package.

Colours

This patch somewhat changes the way rtorrent shows torrents. Seeding torrents have bold titles, there are no half-displayed torrents at the top/bottom when scrolling, and you can configure colours for active/done torrents (ticket libtorrent.rakshasa.no/ticket/1382, which seems to be gone now). Source code and testing hint at these configurable colours: done_fg_color, done_bg_color, active_fg_color, active_bg_color, and at these possible values: 1 (red), 2 (green), 3 (yellow).

Geek’s cellar
A related (though not used in any way for the preparation of the package) resource is rtorrent mods page.

Relatively schematically, applying patches and building the package was performed in these steps (starting within some newly-created directory):

1. sudo aptitude install cdbs devscripts [and whatever else you find you're missing]
2. apt-get source rtorrent
3. dpkg-source -x rtorrent_0.8.6-1.dsc
4. cd rtorrent-0.8.6
5. cdbs-edit-patch 01-ipfilter.patch
6. patch -p1 < /path/to/patch/239
7. exit 0
8. cdbs-edit-patch 02-geoip.patch
9. patch -p1 < /path/to/patch/2064-after-ipfilter
10. exit 0
11. cdbs-edit-patch 03-eyecandy.patch
12. patch -p1 < /path/to/patch/2171-mod-with-canvas
13. exit 0 [you could do all 3 patches together, but I prefer cleaner and manageable approaches]
14. [some weird operation to be explained below]
15. dpkg-buildpackage

Weird operation: I didn’t know how to make dpkg-buildpackage run autorun.sh (which is required for one of the patches I’ve used) before configure (could someone enlighten me how to do that?), so I started a new patch with cdbs-edit-patch, then ran one by one `autoreconf -if`, `./autorun.sh`, `./configure`, exited with zero status and was done with that problem. The resulting “patch” was 2MB large

Imagine you need to install pycassa (which uses easy_install). Here are the 2 (at maximum) very simple steps to have it properly debianized and installed on your Debian/Ubuntu:

• if you don’t have the python-stdeb package: sudo aptitude install python-stdeb
• pypi-install pycassa

That’s it.

Refer to stdeb readme for more information. You will need that if there are dependencies – which might not be resolved automatically by stdeb.

Before stdeb, it wasn’t exactly trivial to make a .deb from python module.

Here’s a simple and clear guide for gmail, which also definitely works with other relay hosts. I’ve used it to configure my ISP’s mail relay (they block outgoing port 25) on a Debian Squeeze laptop.

ask.debian.net is a StackOverflow-like Q&A website built with OSS Shapado.

That’s my first encounter of Shapado, so it was interesting to read Shapado authors’ justification and a related question on meta.SO.

Recently I finally managed to configure remote (aka off-site) backup for my Debian server. As always, I started with a comparison of existing solutions.

Debian has a number of packages enabling remote (over the network) backup: backupPC, backupninja, backup-manager, dirvish, duplicity, luckybackup, rdiff-backup, and some others.

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There is an excellent step-by-step instruction on resetting the bad clusters counter of an NTFS partition with linux-ntfs tools. I’ve checked – it works as expected:

1. Back up important data from partition just in case
2. Find out size of ‘$Bad’ attribute in $Badclus using ntfsinfo -i 8 partition (partition is for example /dev/sda1). It will be the “Allocated size” value in the “Dumping attribute $DATA (0x80)” (there will be two 0x80 attributes. Only one has an “Allocated size” line). Let us write down (remember) this size as ntfs_size.
3. Use ntfstruncate partition 8 0x80 ‘$Bad’ 0 to set $Bad’s attribute length to zero.
4. Use ntfstruncate partition 8 0x80 ‘$Bad’ ntfs_size to set $Bad’s attribute length back to proper value ntfs_size which was recorded in step 2.
5. Boot into Windows and run chkdsk -f diskname. It will find errors and should fix them.

However, Debian’s ntfsprogs package does not have the ntfstruncate binary.

Here’s how you can easily build one yourself (you may need a few extra packages with build tools for that):
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