Linux df command

Hi Experts,
I've this Linux machine:
Linux version 2.6.18-371.3.1.el5xen (gcc version 4.1.2 20080704 (Red Hat 4.1.2-54))

I run df command:

[ora11g@hy]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/vg_ora
                             9.7G  6.8G  2.5G  74%       /u01
/dev/lv_ora
                              59G   47G  8.2G  86%      /sxr/oracle
                                
      
I'd like to know Why the total size 9.7G isn't the same as Used+Available 6.8G + 2.5G (9.3G) and total 59G isn't the same as 47G + 8.2G (55.2)?

Thanks in advance!
ralph_reaAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

KimputerCommented:
Automatically reserved for root (during disaster, like storage fully filled, root can still log in, and do some work).
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
ralph_reaAuthor Commented:
I Know that 5% of the disk might be reserved for root but with plus 5% is still less of total size 59G
0
Alexander Eßer [Alex140181]Software DeveloperCommented:
0
Ultimate Tool Kit for Technology Solution Provider

Broken down into practical pointers and step-by-step instructions, the IT Service Excellence Tool Kit delivers expert advice for technology solution providers. Get your free copy now.

omarfaridCommented:
The difference in size you observed is due to file system over head, There is no exact ratio for this as it depends on factor like number of files or dirs and their sizes.
0
arnoldCommented:
Amount of space used is based on number of files and their space, inodes have a minimum file size (often 4k)such that a 1character file (1 byte)  will account for 4k of space used when computing how much space is left while not being reflected in actual space used.
0
gheistCommented:
Can you post df output without parameters?
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Linux

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.