On Fri, 2019-07-05 at 10:39 -0700, Matthew Wilcox wrote: > On Fri, Jul 05, 2019 at 09:25:48AM -0700, James Bottomley wrote: > > Now the problem: I'd like to do some testing with high depth extent > > trees to make sure I got this right, but the files we load at boot > > are ~20MB in size and I'm having a hard time fragmenting the > > filesystem enough to produce a reasonable extent (I've basically > > only got to a two level tree with two entries at the top). Is > > there an easy way of producing a high depth extent tree for a 20MB > > file? > > Create a series of 4kB files numbered sequentially, each 4kB in size > until you fill the partition. Delete the even numbered ones. Create > a 20MB file. Well, I know *how* to do it ... I was just hoping, in the interests of creative laziness, that someone else had produced a script for this before I had to ... particularly one which leaves more randomized gaps. James