Hello. Whenever I defragment my hard drive I run the Windows
error-checking utility (Scan Disk) before the defrag to check for
errors. I'm helping to build a computer and the owner wants to make a
set of recovery disks for his computer. I ran Scan Disk a few days
ago and found no problems but I would like to run it one last time,
then defrag, before making the owner's Disk Image set.
Question: How often is it safe to run the Windows error-checking
utility/Scan Disk within a certain period of time? BTW, The Hard Drive
of the computer in question is 500 Gigs and takes two hours to run
the utility...I'm patient however!
Any info/advice would be greatly appreciated. Thanx in advance.
Hi Robert,
First, as you are probably aware, what used to be called Scan Disk (DOS
"scandisk" or Windows "scandskw.exe") is now called Check Disk (Command
prompt: CHKDSK), and in either case, scanning the disk has always been
called "Error-checking" on the Tools tab of the drive Properties dialog. As
for what is "safe" - keep in mind that there CAN be "loss of data" with a
full surface scan. Normal drive activity is occasional, but scanning is
continuous use, and two hours scanning may be equivalent to more than twelve
hours normal use. It is not the amount of time a drive is turned on, but the
total activity time that eventually results in minor or major failure. It is
a good idea to do a full surface scan before installing an operating system
on the disk, and once a year afterwards. (If your computer is on the floor
where a foot can bump it, an error scan after every bump would be wise, and
at least weekly cleaning of dust... or duh... simply move it off the floor.)
It is a good idea to do a quick file error scan for lost file fragments,
after a power outage or after manually shutting down a frozen system.
Windows will automatically run CHKDSK if it "thinks" there is a problem.
(Surprise! Now you don't have an excuse for not cutting the grass!
Here is some additional info:
[begin CheckDisk faqtoids:]
WARNINGS: Since Check Disk continually accesses the drive, you may need to
guard against overheating, with cooler room air conditioner setting, or
external fan. You also need to avoid scanning if there is a possibility of
storm lightning or wind-downed branches knocking power out before the scan
completes. Power brown outs may be a problem at certain times of day when
many people arrive home from work in the summer and all boost their air
conditioners to maximum. If the drive has millions of files and/or is 70GB
or larger, the full surface scan may take days, rather than hours. Do NOT
stop Check Disk after it has started. If the progress indicator seems to be
stuck, but the disk activity light is on, at least partly, it is still doing
something! (No light? Listen for anything besides the fan!
[Begin HELP topic quote:]
Start> Help and Support> Search: error checking
Detecting and repairing disk errors
You can use the Error-checking tool to check for file system errors and
bad sectors on your hard disk.
1. Open My Computer, and then select the local disk you want to check.
2. On the File menu, click Properties.
3. On the Tools tab, under Error-checking, click Check Now.
4. Under Check disk options, select the Scan for and attempt recovery of
bad sectors check box.
Notes
• To open My Computer, double-click the My Computer icon on the desktop.
• All files must be closed for this process to run. If the volume is
currently in use, a message box will appear prompting you to indicate
whether or not you want to reschedule the disk checking for the next time
you restart your system. Then, the next time you restart your system, disk
checking will run. Your volume will not be available to perform other tasks
while this process is running.
• If your volume is formatted as NTFS, Windows automatically logs all file
transactions, replaces bad clusters, and stores copies of key information
for all files on the NTFS volume.
[:end quote]
When you click "Check Now", the Check Disk dialog appears, with the selected
volume indicated in the title bar. There are 2 checkbox Check Disk Options:
1) [ ] Automatically fix file system errors
[Same as chkdsk /f]
Specifies whether Windows repairs file-system errors found during disk
checking. All files must be closed for this program to run. If the drive is
currently in use, a message asks if you want to reschedule the disk checking
for the next time you restart your computer. Your drive is not available to
run other tasks while the disk is being checked.
2) [ ] Scan for and attempt recovery of bad sectors
[Same as chkdsk /r]
Specifies whether Windows repairs file-system errors found during disk
checking, locates bad sectors, and recovers readable information. All files
must be closed for this program to run. If the drive is currently in use, a
message asks if you want to reschedule the disk checking for the next time
you restart your computer. Your drive is not available to run other tasks
while the disk is being checked. If you select this option, you do NOT need
to select Automatically fix file system errors. Windows fixes ANY errors on
the disk.
- - -
Note: If you choose to check the drive the next time you restart the
computer, chkdsk checks the drive and corrects errors automatically when you
restart the computer. If the drive partition is a boot partition, chkdsk
automatically RESTARTS the computer after it checks the drive.
- - -
If you run Check Disk without checkmarking either option, (or Start>Run
chkdsk without the /f or /r command-line option,) on an ACTIVE partition, it
might report spurious errors because it cannot lock the drive. This could
happen if open files have not yet been recorded in the file allocation
table. If chkdsk reports the loss of a large number of allocation units,
consider repairing the disk. Chkdsk must be able to lock the drive to
correct errors. Because repairs usually change a disk's file allocation
table and sometimes cause a loss of data, chkdsk sends a confirmation
message similar to the following:
10 lost allocation units found in 3 chains.
Convert lost chains to files?
If you press Y, Windows saves each lost chain in the root directory as a
file with a name in the format Filennnn.chk. When chkdsk finishes, you can
check these files to see if they contain any data you need. If you press N,
Windows fixes the disk, but it does not save the contents of the lost
allocation units.
- - -
[:end CheckDisk faqtoids]
FWIW. --Richard
