ServerBuddies Support Blog

Badblocks - search a device for bad blocks

Important note: If the output of badblocks is going to be fed to the e2fsck or mke2fs programs, it is important that the block size is properly specified, since the block numbers which are generated are very dependent on the block size in use by the filesystem. For this reason, it is strongly recommended that users not run badblocks directly, but rather use the -c option of the e2fsck and mke2fs programs.

This would check the drive “sdb” in non-destructive read-write mode and display progress by writing out the block numbers as they are checked.

This would check the sixth partition of the drive “sdb”, in destructive read-write mode and display progress by writing out the block numbers as they are checked. All data will be overwritten at the block level. If used on an entire disk as in the previous example, it destroys MBRs, partitions and data alike.

Search and substitute

You can easily search for data in the buffer using the vim search command. To enter a search string, press the forward slash (/) key.

The substitute command allows you to quickly replace (substitute) one word for another in the text. To get to the substitute command you must be in command line mode.

The format for the substitute command is:

There are a few modifications you can make to the substitute command to substitute more than one occurrence of the text:

:s/old/new/g to replace all occurrences of old in a line
:#,#s/old/new/g to replace all occurrences of old between two line numbers

:%s/old/new/g to replace all occurrences of old in the entire file
:%s/old/new/gc to replace all occurrences of old in the entire file, but prompt for each occurrence.