[nylug-talk] extfs journalling percentage

[Michael Bubb]

Hello -

I have some questions about the output of df on a Debian server
(low-end Samba server) -

(Linux sweetums 2.6.18-6-686 #1 SMP Sun Feb 10 22:11:31 UTC 2008 i686 GNU/Linux)

Here is a snip the output of df -h:

Filesystem           1K-blocks      Used Available Use% Mounted on
...
/dev/sda1              23M   15M  7,2M  67% /boot
/dev/sda6              70G   48G   19G  73% /home
/dev/sda5             122M  5,6M  110M   5% /tmp

Taking home as an example the actual numbers are:
/dev/sda6             72437948  49776256  18982008  73% /home

The file system in this case is ext3.
On this and other similar servers in my company, I have noticed a 5.1%
'overhead' on the difference between the partition's capacity and its
amount usable.
I realize this is the journal and the blocks reserved for root.


Looking at the man page for mkfs.ext3 I see that there is a '-m' flag
which can adjust this. Do you have recommendations for this? I do not
know much about filesystems and tend to leave the default settings
alone...

If I understand correctly the actual journal is not that big. Most of
this 5% is reserved so that a superuser has access to  an otherwise
full partition. Do you need 5% for this? (ie if you have a 250G
parttion do you need 13G reserved).

Thanks as always

Michael





-- 
Michael Bubb | Hoboken, NJ | 201.736.0870

"Just because Richard Stallman is paranoid doesn't mean Microsoft's
not out to get you. " - (theodc on slashdot)