Mac file system may get corrupted due to journal corruption
Journaling refers to keeping track of changes made usually in a journal before the changes are the made in the main file system. Journaling file system of storage devices follows certain rules for writing journal entries. This journaling file system is supported by HFS Plus and HFS extended file systems. The advantage of having mac system with journaling is that if any unexpected situation such as failure of hardware component, abrupt system shutdown etc takes place recovering from them is easy. Instances of file system repair and data recovery mac is sorted to a considerable extent. Not only this, its use on servers helps increase uptime.
Journal file is maintained in order to sustain integrity of file system after system crashes. It is actually a log file which keeps details of changes made on the disk. If power failure occurs and system fails HFS+ and HFSX data recovery can be done with its help.
The actual process goes on as, when system is started and log information of file is replayed and shown in a well defined state. In this way hard disk gets stored to its working state and its data is now accessible although buffered data gets lost.
But what if the journal gets corrupted? It is quite likely to happen in situations of sudden system shutdown and other hardware errors; similar to what happens with other file system components. When the journal with invalid entries in log is replayed metadata structures and file system also becomes invalid resulting into damages and inaccessibility of data. It may also lead to unbootable system.
- In a case like this FSCK command is used for repairing HFS+ and HFSX file system corruption
- Or you can format disk with disk utility, this will create new file system, metadata etc and data restored from backup
- However, not having the backup can increase your trouble still it can be overcome easily with data recovery software
