When Disk Image Gets Corrupted in Mac

In Mac the disk image is a file that contains all of the contents and the structure of your storage device. Creating disk image is the most convenient method of backing up your precious data stored on the hard drive. There are several different file formats used to create the image of hard drive in Mac and .DMG is the most popular among them.

A .DMG (short for Disk Image) file allows you to have safe password protection and file compression and thus serves both file distribution and security functions. When you open the .DMG file, it is mounted as a drive in Finder. You can easily create .DMG files using tools that are included in Mac OS such as Disk Utility in Mac OS X 10.5, 10.4 and 10.3. You can also manage the .DMG files through command line using hdiutil tool.

Creating disk image is the best option to prevent data loss but sometimes when you try to mount the disk image for accessing data from it, you might encounter the following error message: "The disk image you are opening may be damaged and could damage your system. Are you sure you want to open this disk image?"

Mac OS X detects the damaged disk image before mounting it as the damaged image could results into the data loss. In such situations, you can not restore your data from the .DMG file and thus you need to go for Mac Data Recovery to fix the problem. Mac Data Recovery is the process of scanning your hard drive for extracting the missing, lost or inaccessible data from it.

It is potential in most of the data loss situations and helps you to save you business critical and personal data. You can perform Mac Data Recovery in an easy, safe, quick and automated way using powerful and advanced Mac Recovery software such as Mac Data Recovery. This Mac Recovery software is capable of fixing most of the logical Mac data loss situations.

Recover Data from Unbootable MacBook

You have your Mac in configured status but sometimes when you start your MacBook, it does not boot. All you see when you press power button is the gray screen with a spinning wheel and an Apple logo. This problem generally occurs when you change the system preferences.

If you have changed the system preferences incorrectly before shutting down your MacBook, you may face such kind of behavior. In such situations, all of your precious data becomes inaccessible and thus you need to fix it as quickly as possible.

You can try following things to solve out this problem:

Perform Safe Boot by pressing shift key during startup.
Boot your system in Single User mode by pressing ‘command + s’ keys.
Try to boot your MacBook in Verbose mode using ‘command + v’ keys.
Use Disk Utility from Mac OS X Install disk to verify the drive.

If any of the these solutions does not work, then you need to go for Mac Data Recovery. It is the process of scanning your Mac hard drive and extracting lost data from it.

Mac Data Recovery can easily be performed using Mac Recovery software. Most of the Mac Data Recovery software are downloadable from Internet or come in box version that requires another Mac system to install the software and connect your hard drive to it for scanning and recovering data.

If you do not have another Mac computer, they using these software is not possible. In such situations, you should go for boot DVD of Stellar Phoenix Macintosh Data Recovery software.

You need to just boot your MacBook using boot DVD and after software’s License Agreement you will be directed to recover options screen. This Mac Recovery software is very easy to use and performs safe Mac Data Recovery due to read-only and non-destructive conduct.

Mac OS X Refuses to Boot in Safe Mode

Mac OS X operating system has various booting modes, which include Normal boot mode and Safe boot mode. Safe Boot is a special system troubleshooting boot mode, which is available with Mac OS X 10.2 and later versions. If your system is not booting up properly and you are unable to access your precious data, Safe Mode may help you. However, in some situations, it may not help you fix the problem and you run across data loss situations. At this point, Mac data recovery becomes need of hour.

When you boot Mac OS X system in Safe Mode, the operating system disables fonts, compels directory check, loads only the required kernel extensions, disable startup items, and login items. It helps the operating system boot properly and gives an option to resolve the problem. Mac OS X operating system starts automatic system checking and repair when you boot the system in safe mode.

Under some situations, your Macintosh computer may shutdown improperly when you try to boot it in Safe Mode. In such cases, the system remains unbootable and you can not extract your significant data from it. The problem usually occurs if any of the Mac data structures is damaged.

In case the boot process fails, you need to format the Mac OS X hard drive and reinstall the operating system. It replaces the damaged or faulty data structures of your Mac machine.

Hard drive formatting can fix most of the hard drive problems. The newly installed operating system is usually free from all kinds of data structure errors. However, the major drawback of this process is complete data loss. Formatting removes all the contents of the disk. This behavior puts you in need of Mac data recovery solutions.

At this point of time, you are required to restore lost data from the most recent backup. Backup is the most efficient Apple OS X recovery solution. In order to ensure absolute Mac file recovery, you must have an updated and valid backup in place. An old backup can cause serious problems.

When all your attempts fail, Mac recovery software becomes essential. The third-party applications are particularly designed to perform thorough scan of entire disk using advanced scanning techniques.

Such tools are incorporated with interactive user interface to let you recover lost data in a safe way, without demanding sound technical skills

Catalog File Corruption in Mac

Catalog File is a Mac system file that is used by HFS (Hierarchical File System) File Manager to keep information about hierarchy of the files and directories on Mac volume.

The catalog file is ordered as B-tree file and thus consists of header node, leaf nodes, index nodes and map nodes (if necessary). The allocation block number of first file extent of catalog file is stored in Master Directory Block or MDB.

When you mount the volume, the stored information is copied in the volume control block of that volume. From header volume, File Manager could access node number of the root node of catalog file and from root node, File Manage could find whole catalog file.

A unique CNID (Catalog Node ID) is assigned to the every node of catalog file. For files CNID is file ID and for directories its directory ID. For a given directory or file, the parent ID is CNID of parent directory. When operating system accesses files or data from HFS file system volume, it first interacts to the catalog file and gathers complete information about the hierarchy.

But sometimes when you try to access data from your hard drive, you may get an error message similar to the following:

“Verifying volume
Checking HFS Plus volume.
Invalid record count
Invalid record count
Catalog file entry not found for extent
The volume needs to be repaired.”

After this error message, you can not access data from Mac volume and thus face the critical situations of data loss.

You may encounter this problem because of corruption to the catalog file. Due to same, operating system can not file the required information to read data from volume. To fix this problem, you need to go for Mac Data Recovery. You can carry out Mac Data Recovery in an easy and straightforward way using third party Mac Recovery software.