Re: Software Raid, recovery after drive broke
On Fri, Oct 21, 2011 at 06:12:37PM BST, Tom H wrote:
> I'm sorry that I've confused you. I was just pointing out that the
> demarcation line between mdraid and dmraid isn't as straightforward as
> you made it out to be because mdadm (which is an mdraid tool) can be
> used to manage dmraid arrays.
You hadn't confused me :^)
I've never claimed it cannot. The difference is quite substantial
dmraid discovers block and software RAID devices (eg, ATARAID)
by using multiple different metadata format handlers which
support various formats (eg, Highpoint 37x series).
It offers activating RAID sets made up by 2 or more discovered RAID
devices, display properties of devices and sets
(see option -l for supported metadata formats).
Block device access to activated RAID sets occurs via device-mapper
RaidSetName starts with the format name (see -l option) which can be
used to access all RAID sets of a specific format easily with
certain options (eg, -a below).
mdadm is for kernel software RAID and can handle *any* block device,
no underlying RAID required whatsoever.