http://WWW.sabi.co.UK/ Notes mostly about Linux and computer issues en-GB http://blogs.law.Harvard.edu/tech/rss/ notes {at} notes.for.sabi.co.UK Copyright 2005 P. Grandi GNU OS Linux filesytem JFS ext3 performance virtual memory VM SUSE ALSA Debian Fedora RedHat Free software Microsoft Windows Windows 2000 Windows XP 14000 Tue, 27 Dec 2005 18:25:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051227b More thinking on the various conflicting requirements for my upgrade main drive and its 3 backup drives. The GHST and Maxtor drives match my requirements for both internal and external drives, but I also want diversification of manufacturer. hard drive performance storage backup http://WWW.sabi.co.UK/Notes/anno05-4th.html#051227b Tue, 27 Dec 2005 18:20:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051227 It happens fairly often that my Linux desktop has to swap in processes paged out because of memory pressure, and this happens at 1MiB/s on a disc capable of 40MiB/s, because of lots of arm movement. No relief in sight. Linux performance virtual memory swapping http://WWW.sabi.co.UK/Notes/anno05-4th.html#051227 Tue, 27 Dec 2005 18:00:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226e To enjoy fast disc performance one can buy a large desktop disc and then use only its outer cylinders. hard drive performance server DBMS http://WWW.sabi.co.UK/Notes/anno05-4th.html#051226e Mon, 26 Dec 2005 23:50:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226d Having played some not so recently released FPS games on my average PC they end up with low frame rates. graphics GPU game FPS http://WWW.sabi.co.UK/Notes/anno05-4th.html#051226d Mon, 26 Dec 2005 23:25:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226c Hoping to upgrade my desktop PC to some larger discs, I consider also spin-up power draw as some of those discs will end up as backup discs in an external USB case. Only a few models can do. hard drive USB2 Firewire PSU http://WWW.sabi.co.UK/Notes/anno05-4th.html#051226c Mon, 26 Dec 2005 22:50:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226b Four weeks ago I reinstalled from scratch my Linux root partition, and I have been regularly upgrading it. How much slower overall has it become? Only 1.8 times slower with JFS. filesystem Fedora speed JFS http://WWW.sabi.co.UK/Notes/anno05-4th.html#051226b Mon, 26 Dec 2005 22:10:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226 Some comments on an interesting article as to performance of a Quake 4 update that is multithreaded to take advantage of hyperthreading or multiple CPUs, and some comments on general strategies to achieve good speedups. game Quake 4 hyperthreading SMP Intel AMD http://WWW.sabi.co.UK/Notes/anno05-4th.html#051226 Mon, 26 Dec 2005 22:05:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051219 Having switched from FAT32 to 'ext2' the filesystems I share between MS Windows and GNU Linux on my home PC a few weeks ago, so far I am quite happy with it. Linux MS Windows FAT32 ext2 http://WWW.sabi.co.UK/Notes/anno05-4th.html#051219 Mon, 19 Dec 2005 22:05:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051217 When optimizing vector codes especially on CPUs with SIMD oriented operations it is quite useful to avoid expression oriented constructs like 'x = y + z', and just use ''and becomes'' oriented APIs, like 'x = y; x += z'. vector architecture optimization http://WWW.sabi.co.UK/Notes/anno05-4th.html#051217 Sat, 17 Dec 2005 17:15:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051216 I have found a book that contains a number of mostly well written essays on improving memory reference locality. It is amazing that however little this is practiced it is not yet a totally forgotten area. optimization architecture locality memory cache http://WWW.sabi.co.UK/Notes/anno05-4th.html#051216 Fri, 16 Dec 2005 22:10:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051204 Very interesting and unexpected performance issues with filesystems, in particular 'ext3' with the 'dir_index' option. UNIX Linux Fedora filesystem ext3 JFS http://WWW.sabi.co.UK/Notes/anno05-4th.html#051204 Sun, 04 Dec 2005 21:45:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051203 Comparison of 'bunzip2', 'gunzip' and 'lzop -d' as to decompressing archives containing the same data. UNIX Linux lzop bunzip2 gunzip compression decompression http://WWW.sabi.co.UK/Notes/anno05-4th.html#051203 Sat, 03 Dec 2005 20:10:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051202b After the release of KDE 3.5, some Fedora 4 RPMs are now available. Linux RedHat Fedora RPM KDE http://WWW.sabi.co.UK/Notes/anno05-4th.html#051202b Fri, 02 Dec 2005 18:55:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051202 Some people have run Doom III on a Voodoo 2 SLI graphics card, which does not have bump mapping. This makes clear just how simple is the geometry in Doom III and how effective bimp mapping at adding detail. games Doom III graphics OpenGL http://WWW.sabi.co.UK/Notes/anno05-4th.html#051202 Fri, 02 Dec 2005 17:50:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051130 Some limitations of Yum and its frontends when using Fedora. Linux RedHat RPM Yum KYum YumEx http://WWW.sabi.co.UK/Notes/anno05-4th.html#051130 Wed, 30 Nov 2005 23:00:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051129 I have switched my home PC from Debian Sarge to Fedora 4, and this has been made easier by the way I single out the configuration (or other) files that I modify for my setup. Linux Debian RedHat Fedora CUPS LPRng configuration http://WWW.sabi.co.UK/Notes/anno05-4th.html#051129 Tue, 29 Nov 2005 23:00:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051128 It turns out that the ALSA library package also contains a full Lisp-like language interpreter, which seems to be wholly undocumented. Linux ALSA Lisp Fedora http://WWW.sabi.co.UK/Notes/anno05-4th.html#051128 Mon, 28 Nov 2005 23:00:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051127 There are few reasons to subdivide a storage volume into multiple filesystem, but limitations in file system checkers may effectively impose an upper limit to the size of an individual filesystem. UNIX Linux XFS JFS LVM2 filesystem partition http://WWW.sabi.co.UK/Notes/anno05-4th.html#051127 Sun, 27 Nov 2005 16:40:00 +0000 http://WWW.sabi.co.UK/Notes/linuxNotes.html#majorGames Added some more links and some explanation to the list of major games for GNU/Linux. Linux games http://WWW.sabi.co.UK/Notes/linuxNotes.html?051126#majorGames Sat, 26 Nov 2005 17:20:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051125 Some investigation on alternative reference counting strategies shows mixed results. programming memory management http://WWW.sabi.co.UK/Notes/anno05-4th.html#051125 Fri, 25 Nov 2005 23:50:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051121c Just discovered the latest release of an enhanced pager for KDE. KDE discovery http://WWW.sabi.co.UK/Notes/anno05-4th.html#051121c Mon, 21 Nov 2005 14:45:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051121b A Makefile horror from OpenSolaris, and how to do the same thing is a simpler and more elegant way. development Make build http://WWW.sabi.co.UK/Notes/anno05-4th.html#051121b Mon, 21 Nov 2005 13:15:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051121 Found a nice message by Andrew Morton on the new circumstances of 2.6 Linux kernel development. Sure, they are much better for core kernel developers... Linux kernel development http://WWW.sabi.co.UK/Notes/anno05-4th.html#051121 Mon, 21 Nov 2005 11:35:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051120 Description of and experiences with the IT8221F ATA/RAID chipset and a Q-TEC card with it, under Linux 2.6.14. Linux kernel driver SCSI RAID http://WWW.sabi.co.UK/Notes/anno05-4th.html#051120 Sun, 10 Nov 2005 23:50:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051116 Debian DPKG, APT and version/architecture naming. Linux Debian DPKG APT http://WWW.sabi.co.UK/Notes/anno05-4th.html#051116 Wed, 16 Nov 2005 18:55:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051115 Restoring the driver letter of the system volume of a MS Windows 2000 system. MS Windows system administration registry http://WWW.sabi.co.UK/Notes/anno05-4th.html#051115 Tue, 15 Nov 2005 23:10:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051114 The amount of system CPU per 10MiB of IO is between 100 and 200 MHz. Linux kernel performance http://WWW.sabi.co.UK/Notes/anno05-4th.html#051114 Mon, 14 Nov 2005 19:10:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051113 Found some RH Fedora 4 install images incorporating the various updates since it was released, which can help installing on newer systems. Linux RedHat Fedora http://WWW.sabi.co.UK/Notes/anno05-4th.html#051113 Sun, 13 Nov 2005 22:00:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051110 Hubert Mantel, the cofounder of SUSE and its main kernel maintainer, has resigned from Novell, hinting that Ximian won some internal battle. SUSE probably is going to be wound down. Linux Novell SUSE Ximian http://WWW.sabi.co.UK/Notes/anno05-4th.html#051110 Thu, 10 Nov 2005 20:40:00 +0000 http://WWW.sabi.co.UK/Notes/linuxNVIDIA.html Added advice about switching the 'Composite' extension on or off, and short description of the 'NVRM: Xid' class of issues. Linux driver NVIDIA OpenGL GLX http://WWW.sabi.co.UK/Notes/linuxNVIDIA.html?051108 Tue, 08 Nov 2005 22:40:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051108 Someone reports that using a large filesystem on a PC with just 256MiB of memory results in kernel crashes, no surprise there. Linux filesystem performance reliability http://WWW.sabi.co.UK/Notes/anno05-4th.html#051105b Tue, 08 Nov 2005 19:30:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051106 Discovered an informative comparison of the features of Microsoft Outlook, GNOME Evolution and KDE Kontact via a table of side-by-side screenshots. Linux KDE GNOME Microsoft PIM http://WWW.sabi.co.UK/Notes/anno05-4th.html#051105b Sun, 06 Nov 2005 18:15:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051105b Novell announce that they are focusing on GNOME rather than KDE for SUSE Linux. Linux KDE GNOME Novell SUSE http://WWW.sabi.co.UK/Notes/anno05-4th.html#051105b Sat, 05 Nov 2005 19:40:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051105 Poor sequential disc copy performance uncovers that the Linux defaults for the cache sync daemon are too generous. Linux filesystem performance caching http://WWW.sabi.co.UK/Notes/anno05-4th.html#051105 Sat, 05 Nov 2005 19:15:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051104 Classic observation that a lot of things are easier to get working in a demo than in a production environment, something that is especially applicable to dotcoms/startups... software engineering demo Xbox 360 game physics game AI NaturalMotion endorphin dotcom startup http://WWW.sabi.co.UK/Notes/anno05-4th.html#051104 Fri, 04 Nov 2005 17:30:00 +0100 http://WWW.sabi.co.UK/Notes/linuxSoundALSA.html#ossEmulation Some small updates to the OSS compatibility section of the ALSA notes. Linux OSS ALSA http://WWW.sabi.co.UK/Notes/linuxSoundALSA.html?051101#ossEmulation Tue, 01 Nov 2005 22:40:00 +0100 http://WWW.sabi.co.UK/Notes/linuxNotes.html#majorGames Added proper links and some new entries to the list of major games that can be run with GNU/Linux. Linux games http://WWW.sabi.co.UK/Notes/linuxNotes.html?051101#majorGames Tue, 01 Nov 2005 20:30:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051101 After six weeks, some brief test of how much some types of performance have degraded in my ''root'' JFS filesystem. Around 2.5 times worse than a freshly loaded one. Linux filesystem performance JFS http://WWW.sabi.co.UK/Notes/anno05-4th.html#051101 Tue, 01 Nov 2005 23:35:00 +0100 http://WWW.sabi.co.UK/Notes/linuxNVIDIA.html#commonIssues Some updates on recent driver and kernel issues in the relevant section of the Linux NVIDIA notes. Linux driver NVIDIA OpenGL http://WWW.sabi.co.UK/Notes/linuxNVIDIA.html?051031#commonIssues Mon, 31 Oct 2005 23:50:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051031 As part of the ongoing Linux file system investigations, I have created a new page of notes about that, and the first note is about a summary of how a JFS filesystem is structured. Linux filesystem JFS http://WWW.sabi.co.UK/Notes/anno05-4th.html#051031 Mon, 31 Oct 2005 23:35:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051030c Found a fairly detailed review of an Sun dual core SMP Opteron system. AMD Opteron Sun Microsystems http://WWW.sabi.co.UK/Notes/anno05-4th.html#051030c Sun, 30 Oct 2005 18:55:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051030b Links and some impressions about the Sun Zettabyte File System. Solaris OS filesystem ZFS Sun Microsystems http://WWW.sabi.co.UK/Notes/anno05-4th.html#051030b Sun, 30 Oct 2005 18:25:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051030 After reading a somewhat peculiar test of OOo Calc performance, some of my own testing. The results are disappointing. GNU OpenOffice.org OOo performance Open Document http://WWW.sabi.co.UK/Notes/anno05-4th.html#051030 Sun, 30 Oct 2005 17:50:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051026 Comparing the compilation copyright licenses of SUSE OSS and Fedora, one is not freeware. Linux GNU GPL Fedora Redhat SUSE Novell http://WWW.sabi.co.UK/Notes/anno05-4th.html#051026 Wed, 26 Oct 2005 20:25:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051023 The Qish GC, RSYNC in Python, the Thix OS, survey of backup methods. Free software GC RSYNC OS POSIX backup http://WWW.sabi.co.UK/Notes/anno05-4th.html#051023 Sun, 23 Oct 2005 22:45:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051016 How to create and access quite quickly a lot of small records as records in a Berkeley DB file, not as files in a very large directory tree. Perl database filesystem performance http://WWW.sabi.co.UK/Notes/anno05-4th.html#051016 Sun, 16 Oct 2005 19:05:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051015 Late discovery of a thorough discussion of copy/paste under X11. X11 paste ICCM Emacs http://WWW.sabi.co.UK/Notes/anno05-4th.html#051015 Sat, 15 Oct 2005 20:15:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051014 During a discussion of application cold start times I decide to count how many inode accesses each tries to do. Some word processors do very many indeed. performance OpenOffice.org KWord AbiWord http://WWW.sabi.co.UK/Notes/anno05-4th.html#051014 Fri, 14 Oct 2005 18:55:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051013 Discovered that someone has been doing fairly polished installers for some quality 3D GNU/Linux games. GNU Linux games http://WWW.sabi.co.UK/Notes/anno05-4th.html#051013 Thu, 13 Oct 2005 19:30:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051012d A discussion of the many ways to give advising to Linux on file access patterns, their severe problems, and code examples on using them all hoping some works. Linux advising virtual memory performance http://WWW.sabi.co.UK/Notes/anno05-4th.html#051012d Wed, 12 Oct 2005 20:45:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051012c A quick note about a granularity problem that migh prevents verifying an ISO image (granularity 2KiB) has been written to a DVD (granularity 32KiB). DVD checksum http://WWW.sabi.co.UK/Notes/anno05-4th.html#051012c Wed, 12 Oct 2005 20:30:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051012b A message to the JFS mailing list points to some ''benchmarks'', but what they measure may not be that useful... filesystem performance benchmarks http://WWW.sabi.co.UK/Notes/anno05-4th.html#051012b Wed, 12 Oct 2005 20:20:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051012 While browsing some threads in the XFS mailing list archive I found some interesting threads, especially about preallocation, sync'ing, 'fsck' time and space requirements, and these are some annoations about them. Linux performance filesystem XFS http://WWW.sabi.co.UK/Notes/anno05-4th.html#051012 Wed, 12 Oct 2005 19:10:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051011b Some more notes on clustering, this time for preallocation of clusters, and handling rewriting as overwriting. Linux performance filesystem clustering preallocation http://WWW.sabi.co.UK/Notes/anno05-4th.html#051011b Tue, 11 Oct 2005 19:05:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051011 IO clustering can be adaptive both as to whether it is needed and how much to cluster if it is needed. Short notes on some heuristics. Linux performance filesystem clustering adaptive http://WWW.sabi.co.UK/Notes/anno05-4th.html#051011 Tue, 11 Oct 2005 18:20:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051010 More discussion of IO and filesystem performance, in particular why it is a bad idea to have large block sizes like in the Berkeley FFS, instead of clusters of small blocks like in 'ext2'. Linux performance filesystem clustering block size http://WWW.sabi.co.UK/Notes/anno05-4th.html#051010 Mon, 10 Oct 2005 22:05:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051009 More from the discussion on interactive response, on why file systems are like databases. Some are like VLDBs, and then the issue of how long they take to check arises, and whether file system check utilities are multithreaded ot not, even when the file system code is. Linux filesystem database VLDB http://WWW.sabi.co.UK/Notes/anno05-4th.html#051009 Mon, 10 Oct 2005 13:05:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051008 Some recommendations I have given to a friend about some Linux kernel settings to improve interactiveness. They are followed by an extensive discussion of the 'vm/swappiness' parameter and the various reasons why it should be rather low. Linux performance interactive optimization responsiveness http://WWW.sabi.co.UK/Notes/anno05-4th.html#051008 Sun, 09 Oct 2005 22:30:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051007 I have upgraded my PC by switching from a GF3 Ti200 to a GF6800LE card, and it worked well, and I found some nice tweaking utilities. Also, I could configure it as dual screen even if I have only a single monitor, thanks to a trick. Linux NVIDIA 6800LE http://WWW.sabi.co.UK/Notes/anno05-4th.html#051007 Fri, 07 Oct 2005 23:55:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051006 Impressions of attending the Linux World Expo in London. OpenSUSE is almost invisible, Fedora was very visible. Several interesting freeware projects had a booth. Linux SUSE Fedora http://WWW.sabi.co.UK/Notes/anno05-4th.html#051006 Thu, 06 Oct 2005 22:35:00 +0100 http://WWW.sabi.co.UK/blog/anno05-4th.html#051002 Why one has to check carefully the maximum power ratings of hard discs one wants to put in an external FireWire or USB[2] case, and the surprising wide range of such power ratings. hardware USB2 firewire hard disk power supply http://WWW.sabi.co.UK/Notes/anno05-4th.html#051002 Mon, 02 Oct 2005 19:35:00 +0100 http://WWW.sabi.co.UK/blog/anno05-3rd.html#050929 One of the OOo developers blames the environment for poor OOo startups times. I tend to agree. OpenOffice.org OOo performance http://WWW.sabi.co.UK/Notes/anno05-3rd.html#050929 Fri, 29 Sep 2005 18:00:00 +0100 http://WWW.sabi.co.UK/Notes/linuxNVIDIA.html Updated the note with more details on which driver version supports which cards and work with which Linux kernel. Linux NVIDIA driver Tue, 27 Sep 2005 23:45:00 +0100 http://WWW.sabi.co.UK/Cfg/X11/ Some updates and improvements to my X11 sample configuration files. Linux X11 configuration Tue, 27 Sep 2005 19:45:00 +0100 http://WWW.sabi.co.UK/blog/anno05-3rd.html#050925 A discussion of two subtle sources of bias in file system design testing. filesystem performance http://WWW.sabi.co.UK/Notes/anno05-3rd.html#050925 Sun, 25 Sep 2005 22:35:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050923 A look at the code that implements 'page-cluster', and stern warning about setting it to non zero values. Linux virtual memory performance swapping http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050923 Fri, 23 Sep 2005 18:05:00 +0100 http://WWW.sabi.co.UK/Notes/linuxKDE.html Added to the quick KDE performance advice page two notes about setting lower values for swappiness and page clustering. Linux KDE performance Wed, 21 Sep 2005 23:20:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050921 Having decided to add a feed for the updates to these notes, some struggles with the various RSS formats and their non official DTDs. RSS DTD http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050921 Wed, 21 Sep 2005 19:20:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#05092020 Some more positive experience (despite a suspicious crash) with JFS, and massive improvement in responsiveness by de-untuning a Linux swapping parameter. Linux swapping filesystem JFS performance http://WWW.sabi.co.UK/Notes/swhwAnno05.html#05092020 Wed, 20 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050919 Some discussion and pointers to information about the environment variables that can be used to control and tune the memory allocator inside recent GNU LIBC editions. libc malloc memory tuning performance http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050919 Mon, 19 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050918 A small update about how the card's devices work, and about looking again at ALSA config macros. Also, comments on LSB by Ulrich Drepper, and on the endless cyle of reinvention in software design. Linux ALSA CMI8738 LSB http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050918 Sun, 18 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/linuxSoundALSA.html#chipCMI8738 A small update about how the card's devices work. Linux ALSA CMI8738 Sat, 18 Sep 2005 05:00:00 +0100 http://WWW.sabi.co.UK/Notes/linuxSoundALSA.html#sharing Update about sharing by default in 1.0.9rc2 or later. Linux ALSA asound.conf Sun, 18 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Cfg/ALSA/asound_VIACMI.conf Fixed some mistakes in rarely used part of the sample 'asound.conf' Linux ALSA asound.conf http://WWW.sabi.co.UK/Cfg/ALSA/asound_VIACMI.conf Sun, 18 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/csGreatObs.html computer science research http://WWW.sabi.co.UK/Notes/csGreatObs.html Sun, 18 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/linuxNotes.html#pktwriting Some new notes on how to use the packet writing drivers with the Linux 2.6 kernel. Linux driver UDF packet writing Sun, 18 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/linuxVirtual.html Added a new very draft listing and describing Linux based virtualization technologies. Linux virtualization paravirtualization Xen UML vserver Sat, 17 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/linuxKDE.html Added a new very draft listing and describing KDE and its configuration options, especially related to saving memory. KDE performance tuning virtual memory Sat, 17 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/linuxFonts.html Linux fonts truetype computer modern Sat, 17 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/linuxWiFi.html Linux WiFi ZyDAS driver Sat, 17 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/miscShopping.html Oxford London shopping Sat, 17 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050917 JFS seems to behave better with a patch, and performance seems better, but I wonder why. Linux filesystem performance JFS http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050917 Sat, 17 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050916 Some testing with various values of 'hdparm -a' shows dramatically different speeds. A recent paper says that 'ext3' uses finer grained locking snce 2.6.10, and describes some dubious experimental changes to 'ext3'. Linux filesystem performance readahead elevator ext3 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050916 Fri, 16 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050915 Switching from a highly used 'ext3' filesystem with 1KiB blocks to a freshly loaded JFS with 4KiB brings large gains. It seems also to reduce memory leakage. Some speculation as to why. Space saved by JFS not significant with many many small files. Linux filesystem performance JFS ext3 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050915 Thu, 15 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050914 Switching to JFS runs into bugs. Discussion of why JFS seems to save quite a bit of space over 'ext3' with 1KiB blocks. Linux filesystem performance JFS http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050914 Wed, 14 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050913 More file system testing, with the discovery that an old and well used 'ext3' filesystem is seven times slower than the same when freshly loaded. Moaning about some bugs encountered probably due to non default configurations. Linux filesystem performance fragmentation JFS ext3 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050913 Tue, 13 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050912 More discussion about ATA drives not flushing their cache to the platter when asked to, and related issues. hardware hard drive ATA cache http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050912 Mon, 12 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050911 Large set of links to web pages and online articles about file systems, including both benchmarks and technical information. OS research filesystem articles http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050911 Sun, 11 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050910 Some comments about some file systems being buggy if used with non default options trigger one of my rants about ''works'' being defined by social attrition. software engineering http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050910 Sat, 10 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050909 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050909 Fri, 09 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050908 Fairly careful testing of some file systems as to speed and space used with a sample 'root' filesystem and some typical whole-filesystem operations. Some interesting results. Linux OS filesystem performance ext3 JFS XFS UDF http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050908 Thu, 08 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050907 Some impressions of the difference performance profiles of the Linux disc operation elevator algorithms. They are very different. Linux OS elevator scheduling performance http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050907 Wed, 07 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050906 Some short discussion of my impressions based on a scan of the literature as to what some of the Linux file systems are best for. Linux filesystem features performance http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050906 Tue, 06 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050905 Some data on how much Konsole grows in use. Not pretty. KDE virtual memory performance http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050905 Mon, 05 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050904 Some comments on a comparative test of DVD rewritable media, which perform much better after having been written to a few times. A script to initialize them. Some comments on a new faster DVD-RAM disc type. DVD DVD-RW DVD+RW performance reliability http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050904 Sun, 04 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050903 Linux compression performance lzop gzip http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050903 Sat, 03 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050902 Linux Debian APT Aptitude features http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050902 Fri, 02 Sep 2005 00:00:00 +0100 http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050901 Report of a perplexing statement about the UHCI driver not being needed if the EHCI one is loaded. Also, a pointer to the Conary package management system. Linux driver USB USB2 UHCI EHCI http://WWW.sabi.co.UK/Notes/swhwAnno05.html#050901 Thu, 01 Sep 2005 00:00:00 +0100