On Sat, Jun 16, 2012 at 12:01 PM, Chris Rees <utis...@gmail.com> wrote: > On Jun 14, 2012 5:49 AM, "Wojciech Puchar" <woj...@wojtek.tensor.gdynia.pl> > wrote: >>>> >>>> file to take 900MB or... can i call some system function to "punch" >>>> holes? >>> >>> >>> I think you can only truncate the file at this time, pretty much like >>> brk() works for memory. >> >> >> >> BAD. suppose i keep windoze VM image on filesystem which takes 10GB but > uses 5GB. >> >> i could write simple program to find out what blocks are unused and > then...do nothing. >> > > What if you cp it?
That would be a dd(1) unless we teach cp(1) how to do sparse. I think what he wanted is to tell the OS "I don't need block XX - YY anymore" and the OS creates a sparse hole, which is not available at this time. Cheers, -- Xin LI <delp...@delphij.net> https://www.delphij.net/ FreeBSD - The Power to Serve! Live free or die _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
