Comments on How To Resize RAID Partitions (Shrink & Grow) (Software RAID)

Thank you for tutorial it is very useful. Actually resize is not working with RAID0  

mdadm --grow /dev/md0 --size=188743680
mdadm: raid0 array /dev/md0 cannot be reshaped.

mdadm --grow --help

 This version supports changing the number of
devices in a RAID1/5/6, changing the active size of all devices in
a RAID1/4/5/6, adding or removing a write-intent bitmap, and changing
the error mode for a 'FAULTY' array.

Regards

Ubuntu rescue edition CD ISO has ddrescue which allows you to get most of the data off a failing disk.  If you're lucky without too much corruption!

Using the resize command

mdadm --grow /dev/md2 --size=max

and you get the error:

mdadm: Cannot set device size for /dev/md2 - Device or resource busy

check these (commands are just example):

- make sure there is no RAID rebuild in progress (cat /proc/mdstat)

- make sure there is no opened file (lsof | grep md2)

- make sure it's not mounted (mount | grep md2)

- see if it's the bitmap issue (google for that)

Boot into rescue mode.

 I have a /dev/md0 Raid1 array comprising /dev/sdb1 and /dev/sdc1.

Both partitions are half the capacity of their disks. IE /dev/sdc1 is have the size of /dev/sdc.

How can I resize /dev/md0 to use all the space on the disks?

 Hi Falko.

Thanks for the Tutorial.

I have a few questions or hints:

when i run your Commands as above:

. cp /etc/mdadm/mdadm.conf /etc/mdadm/mdadm.conf_orig

mdadm --examine --scan >> /etc/mdadm/mdadm.conf

It always creates duplicates at the end of mdadm.conf.

If i run:

e2fsck -f /dev/md2

I get the Error:

root@nas:~# e2fsck -f /dev/md2

e2fsck 1.44.5 (15-Dec-2018)

/dev/md2 is mounted.

e2fsck: Cannot continue, aborting.

So should i unmount the RAID and try again?

Best regards

Philipp