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How long will Chkdsk take to run?

Last Modified: 2013-11-14

We suspect that the file system on the DAS attached to our file server is corrupted. I want to run Chkdsk with a /r switch and also /c if possible. My question is: How much downtime should I schedule to allow chkdsk to run?

The volume is 1.6TB in size, with 350GB free. It is formatted with NTFS and is RAID 5 made up of 7 280GB SCSI disks with speeds of 320,000.

Are there any formulas for working out how long this will take, or does anybody know from experience?

Watch Question

The length of time CHKDSK takes to run depends on a multitude of variables that cannot be reliably predicted.  It depends on the number of files in the volume, MFT fragmentation, the number of alternate data streams (if any), the number and types of filesystem journals used (NTFS uses several depending on what features are in use), etc.

It takes longer to scan many small files than it does a few large ones.  It also makes a difference with how much corruption there actually is.  If the filesystem is heavily loaded, however, you should plan on being down for at least an hour.  That's a pretty liberal estimate, but it's rare that it would ever take longer than that.
Jon ScrivenSenior IT Infrastructure Officer

I have to say that I don't agree with cuziyg.  In my experience it can take longer than an hour on my XP machine!  I would expect it to take days, not hours, to do a full CHKDSK.  Can't say I've done it on a disk array of that size, but assuming this is a production server that can't be down for days and days, I'd kick it off on a Friday night and hope that it had finished by the time I got in on Monday.  Will be interested to hear how you get on!
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