On Thu, Jun 5, 2014 at 4:00 PM, John R Pierce <pierce at hogranch.com> wrote: > On 6/5/2014 1:56 PM, m.roth at 5-cent.us wrote: >> mkpart pri 0.0GB x.GB >> *always* gives me aligned partions (and parted - talk about user hostile >> programs! "Not aligned", with not a clue as to what it actually wants....) > > I've taken to always running parted with -a none, as its alignment rules > are based on old concepts like cylinders, heads, which are meaningless > and even WRONG on today's storage devices. (63 heads, 255 sectors is not > uncommon, this means everything at a cylinder or head is on an ODD > sector boundary, ouch!) > New bigger disks may use 4k physical sectors but report 512 for backwards compatibility. If you don't write 4 contiguous sectors it has to read, wait for the disk to spin back around, then write, merging in what you did write. Which means writes will be very slow if your partitions are not aligned on 4k boundaries. I haven't had to deal with many of these yet so I've mostly just installed gparted from epel and used its defaults rather than doing the math myself. -- Les Mikesell lesmikesell at gmail.com