|Dealing with problematic sectors in XP.|
Affecting backups, upgrades, etc
I'm not sure whether this would be considered a hardware question or a software question. It really involves the whole ball of wax.
I'm regularly cloning my entire main hard drive to three external rotating backup drives, using Acronis True Image Home 11. System is running XP Pro... NTFS.
I'm very frequently, though, running into "bad sector" problems that Acronis is seeing on my "C" partition... roughly 75% into the "C" partition cloning. It used to be that Retry would take care of these, but now I'm frequently needing to resort to Ignore.
First, how can I tell what files, if any, are on these sectors? 90Gb of my 120Gb "C" partition are free, so chances are there are no program or data files 75% in, but I'm not sure.
CHKDSK shows no problems. I ran an Extended Test with Western Digital's Diagnostics, and they give the disk a pass, but they also show some weakness in the sector areas reported.
If I use the WD Diagnostic software repair function, say to block the sectors, I believe it will destroy data on the sectors in question. I'm not sure how the system then handles these blocked sectors.
What's not clear also is what the clone drives will see and how they would run if they need to be swapped for a suddenly failed main drive.
The problem has had me paralyzed for a while with regard to things like updates (including... blush... the SP3 update), both because I don't know if the bad sectors that concern me might come into play, and because the backups I'd rely on in are in question.
What's the best strategy for approaching this? I really don't want to do an XP reinstall on a new disk if I don't have to. I have SP3 on a CD waiting to be installed.
I just finished a major project last night, and the XP support deadline is upon us, so this a rushed attempt to check into this.
I've got to admit I've put this on a back burner until now, but diagnosing the pattern of the bad sectors in itself hasn't been easy as I went through various suspects like drive housings, cables, ports on my computer, overloaded tech support in slow economic times, etc etc.
If you are satisfied that the hard disk is faulty, then you absolutely must replace it. In the short term, why not use one of your three backup disks - assuming it fits physically, the machine should just work thereafter.
I'm not sure if chkdsk has a surface scan capability, you may need to run scandisk for that. You may be able to simply mark bad sectors so that they are left unused but this hasn't been common practice for more than a decade (because hard disk reliability has improved greatly). I don't recommend this but it may be an alternative course of action.
kaled - Thanks. I'm actually not certain that the hard disk is faulty, but I agree with your advice, and it has been my intention to dump it if I find it's the problem. But both the WD utility and CHKDSK say the disk is OK, albeit Acronis is forcing me to skip some sectors and the WD utility notes weakness in those areas. So it may be a combination of factors.
Acronis is known to have problems re giving bad sector readings, but reports are not exactly in the context in which I'm seeing them. I've played some email tag with Acronis tech support, and most recently I haven't been able to get back to them.
The backup disks are in fact intended to slip in and out of the machine... that was the whole plan. As they're in eSATA housings, I can also test them or swap them by unplugging my drive in the main machine using a SATA to eSATA cable adapter to the external housing. I have tested the clones from time to time, and they work fine. I've not done the 2 hour Western Digital scan, though, on any of my cloned disks.
Before I commit to replacing the main disk with one of the cloned drives, I'd like to determine first...
a) whether I in fact have any data on those sectors that I'm forced to Ignore when I clone...
b) assuming those sectors don't have data on them, what are the consequences of having skipped sectors during cloning to the integrity of the clone?
c) What would the consequences be of cloning blocked sectors?
I don't want to start using a disk that's ultimately going to give me problems just because I've skipped sectors when cloning.
Once I commit to a disk, I'm concerned that I'd be perpetuating its problems... ie, unless I do nothing on my machine for a day or two but lock everything and make clones one by one and then test re-cloning them etc etc. So, I'm proceeding carefully.
Beyond that, problems along the way have involved things like the use of a USB hub I'd installed on the front of my machine... causing me first to switch to my Firewire hub, and now to the direct Firewire connector on the back of the machine, etc etc etc. Eliminating each apparent weak link in the chain has taken some spare time. I'm learning a lot about things I never thought I'd want to know. ;)
[edited by: Robert_Charlton at 1:29 am (utc) on April 10, 2009]
If a validated backup exists, I would run scandisk with a surface scan and auto-repair overnight, then read the report. If you do this, I would also, temporarily switch off the screen saver for this process and also disable all power-down settings.
I have never used scandisk this way, but if you have a good backup, this may be the quickest and simplest way to get answers. Alternatively, if Acronis includes a similar disk scanning utility (it might) then you may prefer to use that.
Disk imaging packages like Acronis and Ghost only image sectors with data in them. I know that with Acronis you can opt to have the imaging process skip bad sectors so that they will not be included. That's part of the error handling options.
You'll really want to do a thorough surface scan as kaled suggested.
Thanks for various input.
|Disk imaging packages like Acronis and Ghost only image sectors with data in them. |
I'm not actually imaging with Acronis... I'm making full disk clones. In the clone mode, I haven't encountered any skip bad sectors option, and it doesn't seem there'd be one.
So I don't know whether I have a good backup. Clone mode copies the whole disk, so (or but?) there's no validation. There's also no restore process in clone mode. I get a fully cloned disk. That's why I'm concerned what might be on the bad sectors, and what any kind of repair process that, say, moves data does regarding the bad sectors. How would they be seen in a clone?
Ah, that would be cloning your problems, wouldn't it? Bad sectors would be marked as bad in the clone. That's why you'd want to fix those problem sectors on the original before you made a clone.
|WD utility and CHKDSK say the disk is OK |
The only other utility I know that might be effective in fixing your HDD sector problem would be SpinRite, but that's a commercial product.