chkdsk and disk dismount

Posted on 2011-10-21
Last Modified: 2013-12-28
i was attempting to run a chkdsk on a 199GB drive and it is giving me a message which states:

Drive has to be dismounted before running chkdsk.

Is it safe to run a chkdsk? or can i easily bring the disk back online after the chkdsk is done?
Question by:bahti1777
    LVL 14

    Expert Comment

    by:Rob Miners
    Yep you can run chkdsk, it is mounted by the Operating System and allocated a Drive letter so that it can be accessed. By dismounting the volume chkdsk has full access to the drive.

    It should say something like "ALL OPENED HANDLES TO THIS VOLUME WOULD THEN BE INVALID". Would you like to force a dismount on this volume? <Y/N> so select Y

    If programs or drivers maintain an open handle (EG: you have a file open on the drive) to the disk, chkdsk will not run until it has exclusive access to the drive.
    LVL 3

    Expert Comment

    It is better to backup your important data first. There is a risk of data loss when the chkdsk fix your harddisk.


    Especially in the topic:
    /x : Use with NTFS only. Forces the volume to dismount first, if necessary. All open handles to the drive are invalidated. /x also includes the functionality of /f.

    Chkdsk corrects disk errors only if you specify the /f command-line option. 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.

    Accepted Solution

    I ran it and selected dismount option and it only took 1 minute for 199GB. and the drive came back online without any issues. so its all gooood!

    Author Closing Comment

    it was the right one.

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