Mark's Blog

error correction codes and checksums – repair broken downloads

Posted by mark on February 25, 2009 under Technology

tippex-bride

If you ever did, you wondered right: There is no point for checksums in Torrents. Every chunk to download comes already with its own checksum, hence the file once downloaded cannot be corrupt – except it was already seeded so.

But you’re doomed to restart a download if it does not match the MD5 checksum or its extraction yields in CRC errors. Then you might wish to be able to repair that broken download. Unfortunately, although SFVs are tiny – or whatever checksum file format has been used – they can only prove the download valid or not. (See QuickSFV for a reliable tool for this.)

Repairing is easy Read more »

Why badly implemented software RAID5 slows down your PC

Posted by mark on February 20, 2009 under Technology

dali-time

Some time ago I blogged about Windows Server 2008 Software RAID performance and learned that software RAID 5 is unusable at workstations. While opening large files and/or working with them the system became unresponsive. Wondering where the bus congestion might occur I’ve done some research and like to share the math with you for a better insight. Jump to the end for my conclusions and usage scenarios! Read more »

Tags: RAID, Windows Server 2008

ManicTime to track your PC activity

Posted by mark on February 18, 2009 under Technology

manictime-application-and-personal-time-tracking

Do you happen not being able to answer this little question? “What did you do the last half hour in front of your PC?”
The answer could’ve ManicTime, a time tracking tool I am currently reviewing in reaction to Alex Wall’s post about time and self-management. (Alex: having been promoted I expect much backlinks from you!)

ManicTime keeps track of your activity (most probably by measuring mouse movements (their move-distance is measured in “mickeys” BTW) and keyboard input) and stops the time a particular application has focus. As result you get such nice graphs as these: