fill up file system

[Sathish C]

Hi
There is requirement to test a software whne the file system is almost full.Is there a quick and easy way to fill up a file system of lets say 400G , without unmounting this file system and recreating it with a lesser file system size .

Thanx

[Mark Grant]

Apart from shrinking it?

dd if=/dev/zero of=/filesystem/bigfile bs=1024

Will eventaully fill it up completely. However, you can add "count=200000" at the end of that command to come pretty damn close to 400GB and then stop.

[Mark Grant]

Another alternative is to give the filesystem to the nearest DBA for ten minutes.

[Jean-Louis Phelix]

hi,

You can also use the 'prealloc' command :

$ prealloc name size

See man prealloc.

Regards.

[Mark Grant]

Thanks Jean-Loui, thats a new one on me!

[Sathish C]

Wow Jean , this is a damn good one thank you for your suggestion , will let you know how long it took to fill it up withb this command .

[Jean-Louis Phelix]

Thanks guys ... Yes, this is a 'secret' command :^) ! Not very used, don't know why ...

Regards.

[Tim Sanko]

Although prealloc works fine, The DBA will be thankfull for the opportuninty to have storage for once...

The goodwill is always welcome :)

Tim

[Sathish C]

Hi
Thank you for the suggestion . The command does work b ut took about 155 Mins which is quite long . Copying a another file system into this via rcp or scp would have given me the same time to fill this up . I would say still I am looking for something which can do this in maximum 5 to 10 mins unless I am expecting something which can not be done at all .