On 2/24/20 6:34 AM, Petr Vorel wrote: > From: Coly Li <colyli@xxxxxxx> > > When growing a raid0 device, if the new component disk size is not > big enough, the grow operation may fail due to lack of backup space. > > The minimum backup space should be larger than: > LCM(old, new) * chunk-size * 2 > > where LCM() is the least common multiple of the old and new count of > component disks, and "* 2" comes from the fact that mdadm refuses to > use more than half of a spare device for backup space. > > There are users reporting such failure when they grew a raid0 array > with small component disk. Neil Brown points out this is not a bug > and how the failure comes. This patch adds note information into > mdadm(8) man page in the Notes part of GROW MODE section to explain > the minimum size requirement of new component disk size or external > backup size. > > Reviewed-by: Petr Vorel <pvorel@xxxxxxx> > Cc: NeilBrown <neilb@xxxxxxx> > Cc: Jes Sorensen <jsorensen@xxxxxx> > Cc: Paul Menzel <pmenzel@xxxxxxxxxxxxx> > Cc: Wols Lists <antlists@xxxxxxxxxxxxxxx> > Cc: Nix <nix@xxxxxxxxxxxxx> > Signed-off-by: Coly Li <colyli@xxxxxxx> > --- > Hi, > > Coly haven't sent v2, but it's already prepared in openSUSE package [1], > therefore sending it on his behalf. > > Kind regards, > Petr Applied! Thanks, Jes
