Interviewer: Lets say there is a partition of 100GB. When i
tried to create a file using touch command, under any
directory, it was unable to create the file- '100% full
disk space'. I calculated the size of each and every
directory on that partition mannually by adding each file
size & in came out to be total size 50GB. Then where is the
remaining 50GB ? why it is showing disk space 100% full
in 'df -h' command?

Answer Posted / kenji

One possibility is that there are many small size files. "Small" is relative to block size. For example the block size of ext3 file system is 4096. A file size of 4097 uses 2 blocks resulting 50% efficiency. This can explain why 100G partition gets disk full at 50G usage.

Another possibility is there are processes having large open files which are not linked. Such files are not visible by 'ls' commands but their usage still shows up by df -h.

At the event of 'disk full' I would check inode usage as well. Normally max inodes were allocated as "partition size / block size" so insufficient inodes rarely happens. typing 'df -i' doesn't cost you much :-)
I initially thought of "inode full" which you can check by df -i

Is This Answer Correct ?    6 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is the root directory in unix?

696


How do I run a unix script?

682


Is unix a network operating system?

672


How to check logs in unix?

782


How do we change file access permissions?

799


What is .sh file in unix?

730


What is c shell in unix?

635


Is mac a unix system?

659


What is grep|sort give example?

697


How to print/display the first line of a file in Unix?

742


How can you get/set an environment variable from a program?

691


Name the data structure used to maintain file identification?

745


Is the Process before and after the swap are the same? Give reason.

937


In what way the validity fault handler concludes?

738


What is Thread dump in unix?

763