On Thu, 2020-05-21 at 06:15 +0800, Ed Greshko wrote:
On 2020-05-21 05:16, Patrick O'Callaghan wrote:
> Just an update on this. After faffing around trying to recover the
> failing disk, I decided to replace it and start afresh.
>
> I formatted 2 1TB drives with ext4 and created a new md volume as
> RAID1. However they are taking many hours to sync, despite being empty.
> Is this normal?
Just "lurking" here since it has been a very long time since I've
configured RAID.
But I have a question. You said you're starting from scratch? Meaning adding a
RAID
array as separate entity to an existing system? If that is the case, I thought the
steps
would have been.
mdadm --create . . . .
and then
mkfs.ext4 -F /dev/md0
Yes, I finally realised that.
That aside, is
Resync Status : 46% complete
increasing, albeit slowly?
Indeed. It has now finished after I left it running overnight. This is
over a USB3 connection so not that surprising.
This actually happens because of separation of architectural layers,
which is normally a good thing but in this case leads to a huge
inefficiency (even though it's just when initializing). Basically the
RAID subsystem is ensuring that the uninitialised data on these two
disks is synchronised, which is a complete waste of time. In systems
such as ZFS where the layers are less strictly separated, this
presumably wouldn't happen (though I have no experience of it).
poc