Running chkdsk after dirty shut down

Something else is going on which you might investigate. Doesn't sound like a problem for just chkdsk.

I just believe what I see.

 

Looked it up for you:

 

Yes, but that's not chkdsk running everytime windows boots. If the dirty bit isn't set on any drives, chkdsk doesn't run. An improper shutdown will cause it to set the dirty bit. Chkdsk should run and fix any problems when this happens but you shouldn't have chkdsk running everytime you boot. If you see chkdsk run everytime you boot you have problems.

 

OK, split hairs. At least a decision is made at every boot re: running chkdsk /f and that's the point. Do you maintain that the file system can be damaged without the dirty bit set? So chkdsk is sometimes NOT run on a damaged FS?

 

Sparrow , as I said in my earlier post, we are facing weather & power problems out here. There is nothing implicitly wrong with the computers as such.

Thanks for the link.

Is it possible ?

 

No, I wasn't saying that. Unless I misunderstood, you had said earlier that chkdsk runs on every boot on your system. I was just saying that if that's so, something's not right somewhere. Autochk.exe should run and if the dirty bit's not set, chkdsk shouldn't run. It would be hard to believe that there's damage everytime you boot. But, if so.......

 

I confess. my ignorance. I'm learning all the time.

Wish I knew. That's why I brought it up.

PS

Maybe consider UPS (uninterruptable power supplies) for your most important computers?

 

I am using UPS for all my computers and have 2kvA online UPS for servers - but the outage & voltage fluctuations are such that even the UPS fail sometime .

I have put /sos switch in my boot.ini file (as suggested earlier in the post) & Windows shows that its checking the volumes. I don't know whether its chkdsk or autochk that's running. Any way to find out ?

 

If it's chkdsk running you'll know it. You should see the same thing as when you schedule it to run on the next boot. Also, you'll see it without using the /sos switch. One more way to know. If it's chkdsk running, there'll be an entry in the event viewer for it as I stated earlier. It doesn't sound to me like what you're seeing is chkdsk.

 

Zander, as per your description of things, I think that XP is running autochk. But it always reports the volumes as not dirty even if chkdsk finds some problem with them (when its run manually). I don't know what's going on & becoming more and more confused with it - I need to have a definitive answer either way.

On a parallel thought process - is it a safe & good practice to run chkdsk /f on my volumes weekly to see if everything is ok or wait for windows to give up the ghost ?

 

If the dirty bit isn't set it'll report it as "not dirty ". FWIW, once in a great while I experience the same thing (using FAT32). Chkdsk doesn't run at startup but if I run it in windows I find something needs fixing. My guess is that certain things have to happen for the dirty bit to be set. Such as an improper shutdown. If none of these certain things happen to cause corruption or possible corruption, it doesn't get set. That's my take on it anyway. I could be wrong. This is from XPs help file.

I guess you can if you want. To be honest, I don't run it very often. When I do, I run it in windows without any switches. When it's done, nothings fixed obviously, but it'll give you a report as to whether there's any problems or not. I do this because there's no need to reboot when checking the windows drive as long as you don't use any switches. Just chkdsk c: (or whatever drive you want). Then if it reports a problem, you can run it with the /f switch. If not, you continue on your merry way.

 

To be honest, I have not seen any WinXP computers running chkdsk /f automatically in the last approx. 4 years, even if the volume is so badly damaged that Windows won't even load properly (and I see quite a lot of computers in a year).

If the dirty bit was not set in such cases, I don't have any faith in it & would prefer checking all my volumes on weekly basis.

 

Don't see how dirty bit can be set in case of power loss or pressing reset button; it must be set at the time of changes (or possibly just access) to a file in RAM if it's (already) set at boot.

can't mean that it's actively set at boot, for that would mean the disk is already 'chkdsked'.

I see chkdsk run frequently at boot and finding no problem with the disk, which must mean that the dirty bit is set early in the file process, before the catastrophe, i.e. catastrophe from windows viewpoint. However, can't verify that with fsutil. Tried chkdsk (no switch) twice in a row; first said "Windows found problems with the file system." and second time "Windows has checked the file system and found no problems." So go figure.

Not surprised. Think you need to run sans splash screen to see all occurrences. That's my experience.

Agree with your idea of running chkdsk /f manually periodically in your situation. And I''m sure you're backing up everything. You might make a batch file and set it up to run weekly, for example.

 

Come to think of it, you're right. I remember reading about this a while ago but I'll be darned if I can find the info now. Anyway, from what I remember, chkdsk running after a bad shutdown is controlled by a single bit on your hard drive. I could be wrong but it seems to me it's in the boot sector. Anyway, if the bit is set to 0, it means it was a bad shutdown. When windows shuts down, it changes the bit to 1 (possibly the last thing it does?). The next time windows starts, it check the bit and if it's set to 1, chkdsk doesn't run. It gets reset to 0 each time windows boots so the process is repeated the next time windows shuts down. Obviously, if it's set to 0 when you boot the computer, it knows it was shudown improperly and chkdsk runs.

Now, I'll not make the claim that that's the way is exactly but that's the gist of what I remember about it.

 

Here's another idea for rsinfo to consider.

 

Zander

Interesting point, so did some work on it. According to microsoft the only bit mentioned in the disk structure with reference to chkdsk is the dirty bit. See Figure 17.12 Partition Boot Sector for a FAT volume. It's not mentioned in the NTFS Partition Boot Sector information, but that's not surprising, and since XP works the same way in either FS....

 

Well, I don't know what to say. But, it would seem that there would have to be some other trigger (something other than the dirty bit, something like I mentioned) for chkdsk when there's a bad shutdown. Other wise if you typed fsutil dirty set C: at command prompt, the dirty bit would always be set. How else would it get set if the computer locked up or if junior happened along and pressed that button on the front of the computer he always wondered about? Am I the only one that's confused?

 

Nope.. Sorry. You've just joined me. Think it's a problem with proprietary OSs. Too many secrets under the hood.

 

sparrow, my disks are fine & have no bad sectors. Anyway since I am looking after about 100 computers, this issue does not pertain to one or two but to all of them.

I had asked this question because some of my clients had this problem of data corruption which was rectified by running chkdsk /f - but I am looking for an automated system to run it & not manually.

 

Welcome to the club