Updated: 2005-11-26
Created: 2002
There are many meta problems and problems with GNU/Linux, but one metaproblem stands out.
This problem is that there are two immensely different levels of GNU/Linux usage: what is supported by the distribution, and what is supported if the user can install something outside the distribution. There is also of course the level where one can extend what GNU/Linux supports by writing something new, like a new application or a new device driver.
What I have found is that for ordinary users it is difficult enough to make use of what distributions offer; it is very difficult for them to install anything that is not ready-made for installation.
TBC
Listed at
Texturizer.net/firefox/
and at
http://extensionRoom.mozDev.org/.
http: links, and downlaod files.First of all there is no such thing as a “typical” PC, but for the sake of argument let's imagine one with at least 40-80GB, with a CPU with a PR of 1000-3000, and used with a GUI framework like KDE or GNOME, for web surfing, program development, documentation, and other “typical” desktop tasks.
My assumption is that most of the data will be media, such as program archives, games, music files, movies, digital photographs, and that a smaller part will be documents and program, some of them with a confidential content.
Then I would suggest something like 8-12GB for /,
2-4GB for swap, 4GB for a partition where to put your own home
directory, and the rest for data storage, perhaps some of its as
FAT32 (for platform independent data files like MP3s, movies,
pictures, ...). Note that very large FAT32 partitions are usually
a bad idea.
I prefer as Linux filesystem to have ext3 for everything, it is well shaken down and performs OK. Other plausible candidates include JFS and ReiserFS, even if in general they are less commonly supported than ext3 and a bit more complicated.
For a 160GB (152Gib) disk, I would like this layout, which for the sake of example includes dual booting with MS Windows:
| Size | Mounted on | Description |
|---|---|---|
| 12GB | / |
ext3 |
| 12GB | /fs/c, C: |
FAT32 for MS Windows root. |
| Size | Mounted on | Description |
|---|---|---|
| 4GB | swap | encrypted swap |
| 4GB | /fs/home |
encrypted ext3 (home directory) |
| 4GB | /fs/others |
encrypted ext3 (other stuff, like work etc.) |
| 30GB | /fs/store |
ext3 for Linux downloads etc. |
| 30GB | /fs/d, D: |
generic data, smaller files (downloads, games) |
| 56GB | /fs/e, E: |
generic data, larger files (MP3, movies, ...) |
I normally prefer to make sure the ext3 partitions have a block size of 1024 instead of the 4096 default, and a manually specified number of blocks per inode (about one inode per 12000 bytes for the root, and for many more bytes for archival partitions).
If you are wondering why it is important to keep FAT32 partitions small, or at least under the critical power-of-2 boundaries, it's because of growing cluster sizes.
Finally, some principles I use when devising a partitioning scheme:
There is a subtle but deadly problem with AGP cards and AMD processors if 4M virtual page mappings are enabled. This results in hard lockups. This happens fairly often for example if the 3D accelerated NVidia driver for XFree86 is used, even if it is used just in 2D mode.
The solution is to disable 4MB virtual page mappings with
the boot parameter mem=nopentium. After adding this
my system is no longer locking up, which it was doing especially
when paging through collections of images.
I have recently discovered a very disappointing problem with SB Live! cards: if the volume control on a subdevice is too high, there is significant distortion of loud acute sounds, for example trumpet bits in jazz pieces.
The distortion does not happen when the master volume is at some high level; only when a subdevice volume control is at some setting higher than approximately 2/3 of the maximum. The same sound output can be obtained by either having a higher master volume with a lower subdevice volume, or viceversa. In the first case there is no distortion, in the second there is.
This is far more apparent with the Linux drivers than with the Windows drivers, and I think there is a reason for this: the Linux drivers give access to the full range of volume settings, which is from 0 to 31. The Windows drivers do only display values in percentages from 0% to 100%; my impression is that the 100% of the Windows drivers is significantly less loud than the 31 setting under Linux. This probably means that Creative are aware of the distortion and do not let the subdevice volume to be set to a high value. However I could reproduce the distortion under Windows too, at values close to 100% of the subdevice volume slider.
Amazingly many modern cameras with a USB connection emulate a USB mass storage (flash) reader/writer instead of using some particular upload/download protocol. This means that the appear to hosts systems as USB connected removable media disk drive, a bit like an external SCSI connected ZIP disk drive.
Under Linux the can be accessed by setting up the USB subsystem
and then, after the camera is connected with its SmartMedia in,
loading the usb-storage module or, with Linux 2.6.10
and later, the ub modle, which takes over flash USB
storage drives from usb-storage as discussed in a
thread in the linux-kernel mailing list:
ub driver is compiled, the
usb-storage code stops handling the devices
handled by the ub driver, that is all USB
storage devices that implements the bulk only
subset of the transparent SCSI protocol, in other
words usually flash devices.ub driver is still highly experimental,
it supported by DEVFS but not in legacy device name mode,
and is meant to be more reliable than
usb-storage for slow devices (like flash card
readers).Either driver module will probe the USB bus, find the camera as
a disk drive, and create a new virtual SCSI adapter on which the
card will appear as a virtual SCSI disk (usb-storage)
or a virtual disk device (ub) under
/dev/ub/.
The vital detail is that as a rule the SmartMedia will contain
a VFAT filesystem either in the whole volume or in
the first partition of the volume; that is, if your camera's
SmartMedia appears as the SCSI virtual disk /dev/sda,
the VFAT filesystem will be either /dev/sda or more
commonly /dev/sda1.
You can therefore access the content of any SmartMedia
inserted into the camera by mounting it with a command like
mount -t vfat -o noatime /dev/sda1 /fs/usb.
Because the flash memory has a limited number of writes, and is
slow at writing, it is important to use -o noatime,
and ideally just mount the filesystem read-only too whenever
possible, and remount it read-write only when updating it.
There is now a Flash Memory HOWTO about this.
It is apparently common for some PPP terminal servers used by many ISPs for dial-in ports to have difficulty handling extended TCP options. In particular they seem to have difficulty with timestamps, but selective acknowledge, window scaling and ECN seem also to cause trouble.
Under Linux you can check this by running pppstats -w
10 while the connection is up and you are downloading;
the count under VJUNC should be zero or much
smaller than the one under VJCOMP.
The solution is easy under Linux: copy 0 to the
tcp_timestamps (or tcp_sack,
tcpd_window_scaling) file
under /proc/sys/net/ipv4/.
Don't blithely disable all of the options; selective acknowledge is fairly valuable, and probably window scaling is too, for example.
ECN seems to cause trouble pretty often
with CISCO
routers
which are very common. The solution is turn ECN off under Linux
by copying 0 to the tcp_ecn file under
/proc/sys/net/ipv4/.
The ESC680 is a 72/144/360/720DPI printer that uses the Epson ESC/P2 command set for printers, that has been extended several times.
The ESC680 is therefore simulating a dot matrix printer (rather than a laser printer). This also means that it can print text without any driver, and even in a range of fairly good quality native fonts.
However its normal mode of operations is as a grayscale or color raster printer, in which some kind of filter takes input in some kind of format and produces a bitmaps or pixmap with inside some ESC/P2 codes that put the printer into and out of raster mode.
Things are a bit complicated as higher resolution modes are achieved by doing multiple passes of overlapping strips of pixels, so it's not quite straight bitmap or pixmap dumping.
Things are also complicated a bit by the fact that there 144 B&W ink nozzles (pins) and 48 each for each CMY color, so grayscale and colorm printing are probably handled slightly differently.
There are some filters that produce as output ESC/P2 codes and pixmaps/bitmaps for ESC printers and in particular the 680:
stc800pl.upp.
There are quite a few “major” games for Linux on i386, where by “major” one means with rich 3D graphics and high production values and good game play, and here I am listing my favourites in three categories: freeware, commercial and natively ported, commercial but only partly ported, requiring data files from the MS Windows edition to operate.
Several of the ported or free or freed games are available
prepackaged for major distributions as a .rpm or
.deb, or even with a nice installer from
these very nice people.
Some other lists:
Linux is not the only free software operating system; but for example the various BSD variants are not GPL'ed, and this reduces their utility to the free software movement (but not to Microsoft).
However, there are several other free software OSes than Linux and the BSD variants:
TBC
CDfs is a file system for Linux systems that `exports' all tracks and boot images on a CD as normal files. These files can then be mounted (e.g. for ISO and boot images), copied, played (audio and VideoCD tracks)... The primary goal for developing this file system was to `unlock' information in old ISO images.
