[EMAIL PROTECTED] wrote: >On Mon, 29 Apr 2002 19:56:59 +0200, Matthias Andree <[EMAIL PROTECTED]> > said: > > > >>Barring write cache effects, fsync() only returns after all blocks are >>on disk. While I'm not sure if and if yes, which, Linux file systems are >>affected, but for portable applications, be aware that sync() may return >>prematurely (and is allowed to!). >> >> > >And in fact is the reason for the old "recipe": > # sync > # sync > # sync > # reboot > >On the older Vax 750-class machines, sync could return LONG before the blocks >were all flushed - the second 2 sync's were so you were busy typing for >several seconds while the disks whirred. Failure to understand the typing >speed issue has lead at least one otherwise-clued author to recommend: > # sync;sync;sync > # reboot > >(the distinction being obvious if you think about when the shell reads the >commands, and when it does the fork/exec for each case....) > > > Finally I understand this. Doing more than one sync always seemed mysterious to me.;-)
Thanks Matthias. Hans
