August 3, 2008: Observing chkdsk
I recently had occasion to suspect there might be problems on my Vista laptop’s C: drive, so I scheduled a chkdsk (more technical explanation of chkdsk in this KB article). Since chkdsk cannot run on a mounted drive, and obviously one cannot unmount the system drive, the chkdsk was scheduled to run at next boot. But my suspicions were not really urgent, so I didn’t reboot right away.
Two days later, when I did get around to rebooting, the chkdsk surprised me a bit - I forgot I had scheduled it. But that’s just the framing story for two things I noticed during the chkdsk. The first may be a bug. During stage 4 (check for bad sectors, according to KB187941), chkdsk reports 15% the whole time. The reported completion percentage never changes:
84791 / 163056 = 52%. I tried to get a shot of it just as this stage was completing, but at about 140,000 files, the process sped up considerably, and moved on to the next stage before I could get the camera positioned. Anyway, it stayed at 15% right up to the finish of this stage. Other stages did report their percentage more or less accurately (I didn’t do the math). By the way, this stage was very, very slow on my system. It probably took an hour to complete, though I did not time it.
Now here’s the other thing - apparently chkdsk clears the SuperFetch cache. Here’s ATM, a few minutes after the reboot completed:
Note the almost-missing big yellow bar in the graph. Now remember just a few days ago I put up this screenshot of ATM showing a nice fat yellow cache bar:
It’s not a big deal, though. My system has now been running for about 2 more hours, and I have my fat yellow superfetch band again. Still, it’s a nice thing to be aware of.
