Re: [linux-lvm] Advanced Format disks mixed with regular disks?

[Karel Zak <kzak@redhat.com>]

On Mon, Mar 14, 2011 at 04:00:57PM -0400, Mike Snitzer wrote:
> On Mon, Mar 14 2011 at  3:13pm -0400,
> Ron Johnson <ron.l.johnson@cox.net> wrote:
> 
> > On 03/14/2011 12:17 PM, Mike Snitzer wrote:
> > >On Mon, Mar 14 2011 at 12:47pm -0400,
> > >Ron Johnson<ron.l.johnson@cox.net>  wrote:
> > >
> > >>Hi,
> > >>
> > >>Is there any concern with mixing 4KB-sector drives with 512-byte
> > >>sector drives in the same LV?
> > >
> > >Both LVM2 and Device Mapper have been updated to accommodate stacking
> > >such a mix of drives.
> > >
> > >See this for a bit more detail:
> > >http://people.redhat.com/msnitzer/docs/io-limits.txt
> > >
> > >Particularly, the "Stacking I/O Limits" section.
> > >
> > >The concern raised for partial (4k) writes to the 512b drive was
> > >discussed a bit more here: http://lkml.org/lkml/2010/2/22/295
> > >
> > 
> > Does this mean that util-linux v2.17.1 fdisk correctly handle AF
> > disks?  (Note that I will *not* be booting off an AF device.)

 ideally util-linux >= 2.17.2 (e.g. RHEL6)

> > 
> > ftp://ftp.kernel.org/pub/linux/utils/util-linux/v2.17/v2.17.1-ReleaseNotes
> > 
> > fdisk:
> >    - cleanup alignment, default to 1MiB offset  [Karel Zak]
> >    - don't check alignment_offset against geometry  [Karel Zak]
> >    - fallback for topology values  [Karel Zak]
> >    - fix ALIGN_UP  [Karel Zak]
> >    - fix check_alignment()  [Karel Zak]
> >    - fix default first sector  [Karel Zak]
> >    - use "optimal I/O size" in warnings  [Karel Zak]
> >    - use 1MiB offset and grain always when possible  [Karel Zak]
> >    - use more elegant way to count and check alignment  [Karel Zak]
> >    - use optimal_io_size  [Karel Zak]
> 
> Given that changelog, yes.

 Yes, it works. Note that you have to disable (-c -u) DOS compatible
 mode. The mode is disabled by default in Fedora, but enabled in RHEL6.

 Some hints:
 http://karelzak.blogspot.com/2010/05/4096-byte-sector-hard-drives.html

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com