Re: how do i fix these RAID5 arrays?

[David T-G <davidtg-robot@justpickone.org>]

Roger, et al --

...and then Roger Heflin said...
% You may not be able to grow with either linear and/or raid0 under mdadm.

Um ...  uh oh.

I did some reading and see that I had confused adding devices with
growing devices.  I'll add devs to the underlying RAID5 volumes, but
there will only ever be six devs in the RAID0 array.

What do you think of

  mdadm -A --update=devicesize /dev/md50

as discussed in

  https://serverfault.com/questions/1068788/how-to-change-size-of-raid0-software-array-by-resizing-partition

recently?


% 
% And in general I do not partition md* devices as it seems most of the time
% to not be useful especially if using lvm.

Well, yes, but I like to have a separate tiny "metadata" partition
at the end of the disk (real or virtual for consistency) where I keep
useful data.  I could live without it on the big array, though.


% 
% so here is roughly how to do it (commands may not be exact)> and assuming
% your devices are /dev/md5[0123]
% 
% PV == physical volume (a disk or md raid device generally).
% VG == volume group (a group of PV).
% LV == logical volume (a block device inside a vg made up of part of a PV or
% several PVs).
% 
% pvcreate /dev/md5[0123]
% vgcreate bigvg /dev/md5[0123]
% lvcreate -L <size> -n mylv bigvg
% 
% commands to see what is going on are : pvs, lvs, vgs.
% Then build a fs on /dev/bigvg/mylv   Note you can replace bigvg with
% whatever name you want, and same with the mylv.
[snip]

Thanks for the pointers.  I'll go off and read LVM docs and see if I
can come up to speed.


Have a great day

:-D
-- 
David T-G
See http://justpickone.org/davidtg/email/
See http://justpickone.org/davidtg/tofu.txt