[SOLVED] How to find out how long a tar gzip would take, test mode?

anon091 · 07-01-2010, 04:36 PM

I have a massive directory that i want to make a .tar.gz out of. Only problem is I have no idea how long the entire process would take. Without actually doing it, is there any way to guage that?

I'm guessing the answer is no, but figured I'd ask. I have to shut down services on the server before I could do it, so i'm trying to see how big of a window I would need.

Tinkster · 07-01-2010, 05:48 PM

It will depend on three factors: read speed on the file-system you
wish to archive, CPU for compression and write speed on the file-system
you'll be putting the tgz on ... so no, no simple way to gauge it.

You *could* do a test run, and discard the result, on a subset and
interpolate (if the test data set was representative).

Cheers,
Tink

anon091 · 07-01-2010, 05:49 PM

Thanks Tinkster for confirming my initial thoughts.

If you do a test run, does that actually write the tgz file and stuff? or just go through the process somehow without all that i/o on the disk?

Tinkster · 07-01-2010, 05:57 PM

No, I did mean grabbing a subset of your files to be backed up, and
actually write it out to disk - otherwise you won't get a feel for
the whole process.

Cheers,
Tink

anon091 · 07-01-2010, 05:59 PM

Gotcha. Wasn't sure if you meant there was actually a test mode too. I'll probably just grab a portion of the files and see how long that takes, then estimate from there. Thanks!