5 Phases of Check Disk utility- The internal working

CHKDSK is a command in the Windows command line to run a program, or utility, known as Check Disk. The Check Disk program is there to make sure that the computer’s files and file system are in order. It checks the file system and metadata of a volume for logical and physical errors then displays the correction of errors. In this article we discuss about 5 phases which are performed by CHKDSK during it verifies the file for errors.

CHKDSK Stages: How CHKDSK Preform its operation?

We have to understand first that how Check disk performs in command window. The whole activity of Chkdsk is divided in 3 major phases where it examine all metadata on the volume, where metadata is data about data. NTFS protects the metadata by using transaction log.

First Stage of CHKDSK- Verify Files

During First phase Check disk perform the operation of verifying files, in this stage CHKDSK analyze each file record segment (FRS) in volume master file table (MFT). File and directories on NTFS formatted volumes are identified by its own file record segment (FRS) in MFT and the percent which calculate that how much MFT has been verified.  In the end of this phase CHKDSK shows what spaces is in use in MFT and on volume. It also knows what space is available for MFT as well as on volume.

Second stage of Check Disk tool- Verify Indexes

Performing its second phase CHKDSK verifies indexes and count 0 to 100 in percent. In this stage CHKDSK examines all NTFS directories and calculation in percent which shows that those remaining directories which have to be checked. Here CHKDSK examines that each file and directory represented by FRS in MFT is referenced by at least one directory, and then it checks the various time stamps and size information of the file are updated or not. At the end of this stage CHKDSK confirms that there is no ‘Orphaned’ file, files which are listed in FRS but not listed in directories. If CHKDSK found the directory holds a file which is no longer exists then CHKDSK create a root directory and place the file there. If directory listings are found those FRSs which are not correspond to the file listed in directory, then CHKDSK remove that directory.

Third Stage of CHKDSK utility- Security Descriptor

In the third pass of check disk it verifies about the security descriptors and count from 0 to 100 in percent. In this phase CHKDSK examines each of the files and directories which are associated with security permissions. Check Disk examines in this stage that every security descriptors are working properly or not with all given permissions in an appropriate way.

Fourth & Fifth Stage of CHKDSK

This phase in check disk is only generated by using /R switch. /R is used to locate the bad sectors in volume’s free space and recovers the readable information. CHKDSK reads every sector on the volume to confirm stability. In fourth stage it verifies the clusters which are used and in Fifth pass it examines those clusters which are not in use.