Mac machines are termed the ‘Excellent’ computer though. However, is your Mac really performing exactly how they used to?
You might not be able to respond in favor of your Mac. Anyway, the main thing of concern for you is that your Mac is facing performance issues. Gradual performance downfall and random error messages are causing troubles like inaccessible partition, missing or corrupt files, etc. are very common in such a state.
Just have a look at the following one.
"Invalid B-tree node size. This disk needs to be repaired." – is an error appeared when a particular volume that is severely corrupt is accessed. This causes data inaccessibility and might eventually lead to hard drive corruption, causing data loss.
Causes of the Error
Each volume on your Mac has certain information (such as files, directories, file threads, and directory threads) associated with it. Every single file that you save on your Mac has its unique entry in the index table in B-Tree format. Every time you access a file on your Mac, the OS X has to traverse this tree to locate it. The aforementioned error message is displayed when the B-Tree has some sort of corruption an OS X fails to traverse it. The same issue sometimes leads to Mac boot failure and eventually causes data inaccessibility.
Fixing the Error
Fixing the “Invalid B-tree node size. This disk needs to be repaired.” error appeared on your Mac requires repairing the corrupt or inaccessible volume with Stellar Volume Repair since Mac OS X inbuilt disk management tool (i.e. Disk Utility) fails to conquer this error. Following are the steps you need to follow:
1. Install and run Stellar Volume Repair on your Mac machine.
2. Click the Continue button to proceed.
3. In the list of volumes shown to the left, select the corrupt or inaccessible volume, and then click Rebuild option in the toolbar.
(With this, the software starts rebuilding the volume. Meanwhile, it fixes the issues efficiently.)
4. As the result of volume repair, you will see one of the following cases:
a. The volume is correct and there is no need to rebuild the directory.
b. Stellar Volume Repair rebuilds directory.
c. The volume is severely damaged or corrupt and it cannot be rebuilt.
(You will be given the Rollback option if you had set it before in the Preferences menu. It will take you to the previous state of the volume again.)
Note: When the volume is severely damaged, you have to delete and recreate it. Therefore, always keep a recent backup of your crucial data.