On Wed, 13 Jul 2011 12:17:02 +0200 "maciej.naruszewicz" <maciej.naruszewicz@xxxxxxxxx> wrote: > From: maciej.naruszewicz <maciej.naruszewicz@xxxxxxxxx> > > Actual sizes of disks from different producers may vary, > even though they are claimed to have the same amount of > space Are you sure about this? It was my understanding that some industry association has arranged an agreement so that this does not happen. http://www.idema.org/wp-content/plugins/download-monitor/download.php?id=1223 Do you have actual evidence that different drives from different manufacturers have similar but not identical sizes? NeilBrown > Since creating arrays using IMSM metadata doesn't > support resizing arrays yet, there might be problems when > replacing a disk with a slightly smaller one. > > For the time being, disk coercion will not be implemented > for IMSM, however it would be a good idea to inform the > user how to deal with it. Our suggestion is to mention it > in the manual page under the -z option and advise the user > to create arrays using a little less space than the disks > have. > > Additionally, the part 'This value can not be used > with CONTAINER metadata such as DDF and IMSM.' was not > clear and was replaced. > > Signed-off-by: maciej.naruszewicz <maciej.naruszewicz@xxxxxxxxx> > --- > mdadm.8.in | 13 ++++++++++--- > 1 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/mdadm.8.in b/mdadm.8.in > index 7e8981e..2690e2d 100644 > --- a/mdadm.8.in > +++ b/mdadm.8.in > @@ -440,9 +440,16 @@ problems the array can be made bigger again with no loss with another > .B "\-\-grow \-\-size=" > command. > > -This value can not be used with > -.B CONTAINER > -metadata such as DDF and IMSM. > +Actual sizes of disks from different manufacturers may slightly differ, even if > +they are said to have the same amount of space. Changing array's size with the > +.B "\-\-grow \-\-size=" > +command is not supported yet by external metadatas such as DDF and IMSM. Creating RAID > +arrays with the > +.B \-z > +option is advised so that the array's size is a bit smaller than the actual maximum > +available data disk's size. Otherwise, replacing a disk in an array with the 'same' > +disk from a different manufacturer is not guaranteed to be always possible due to > +difference in device sizes. > > .TP > .BR \-Z ", " \-\-array\-size= > > --------------------------------------------------------------------- > Intel Technology Poland sp. z o.o. > z siedziba w Gdansku > ul. Slowackiego 173 > 80-298 Gdansk > > Sad Rejonowy Gdansk Polnoc w Gdansku, > VII Wydzial Gospodarczy Krajowego Rejestru Sadowego, > numer KRS 101882 > > NIP 957-07-52-316 > Kapital zakladowy 200.000 zl > > This e-mail and any attachments may contain confidential material for > the sole use of the intended recipient(s). Any review or distribution > by others is strictly prohibited. If you are not the intended > recipient, please contact the sender and delete all copies. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
