[wplug] Help deciding a RAID+LVM+LUKS setup

Drew from Zhrodague drewzhrodague at zhrodague.net
Mon Jul 22 10:01:56 EDT 2013


> I've never had any issues with RAID 5 myself; it's saved my bacon more
> than once.  I'm a big fan of hardware RAID, because it doesn't matter
> what OS you're running, and the controller just deals with managing the
> RAID itself - you can pull a failed drive and replace it, and the
> controller rebuilds the parity all by itself, the OS doesn't even know
> anything's happening.  But you're right, if you ever think you might
> want to swap out your disk controller with a different one, you get to
> dump/restore all your data, because one vendor's controller won't
> typically recognize the RAID structure created by some other vendor's
> controller.

	I'll second never having any issues with RAID-5, though I only use 
mdadm for raid. Usually my volumes outlive the machine they are on, so a 
hardware controller that does RAID won't work for me - especially if the 
new machine will not physically accept the old controller. Some 
mainboards have a built-in RAID controller, which is generally unique to 
the mainboard, and not portable to other mainboard RAID controllers. 
(grumble grumble Sun grumble grumble).

	I have had trouble moving an md RAID from EL5 i386 to EL6 x86_64 - had 
to copy the data over the network - the md volume wouldn't assemble or 
read properly on the new host, so I put them back into the old host for 
copy over gigabit ethernet.

	That being said, md is supposed to allow you to change the type of raid 
without losing any data - adding disks, changing type, etc. I dunno how 
it does this, and I have no experience with it.

	I get about 3-5 years out of a RAID-1 pair of disks, and I've been 
using mirrored pairs at home since about 2003.


-- 

Drew from Zhrodague
kitchen biochemical warfare
drew at zhrodague.net


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