Bugs: What you see is not always what it is

Came across a neat nugget of historical information today that yet again proves that the software/hardware bug behavior that you may see on the surface might imply something totally opposite to what the problem actually is.

The “bug” existed back in the old times of the floppy drives. These drives seemed to fail very quickly on linux systems compared to MS DOS/Windows. Now, a normal observer would say linux had bad handling of the drives or was doing something messy that made these drives crap out ever so often. But as it turned out, the issue was the complete opposite. The real reason behind this problem was that linux was rock solid and stable compared to MS Dos.

Woah!! Hold on a minute, you say. How can being stable lead to hardware failure? Well, since DOS used to crash (or had to be rebooted) so often, it used to do a check on the floppy at boot up which used to shake up any dust on the drive. Since no such frequent reboots were required in linux, it caused a dust build up on the drive ultimately leading to it’s premature demise . Solution: A special program “diskseekd” whose sole purpose was to check the disk periodically to shake the dust out of the system and keep it happily working. Learned something nice today, isn’t it? Below is an excerpt frm the man page of diskseekd

Several people have noticed that Linux has a bad  tendency  of  killing floppy  drives.  These  failures  remained completely mysterious, until somebody noticed that they were due to huge layers of dust accumulating in  the floppy drives. This cannot happen under Messy Dos, because this excuse for an operating system is so unstable that it  crashes  roughly every  20  minutes  (actually  less  if you are running Windows).  When rebooting, the BIOS seeks the drive, and by doing this, it  shakes  the dust  out  of  the  drive mechanism. diskseekd simulates this effect by seeking the drive periodically.  If it is called as diskseek, the drive is seeked only once.