[prev in list] [next in list] [prev in thread] [next in thread] 

List:       opensolaris-help
Subject:    Re: [osol-help] Convert to a different type of vdev
From:       Edward Ned Harvey <solaris () nedharvey ! com>
Date:       2009-03-26 4:57:07
Message-ID: 001601c9adcf$53dd3010$fb979030$ () com
[Download RAW message or body]

> Now I would like to convert my non-mirrored disk to a mirror (or
> raidz).  But I don’t see any option to do such a thing.  Is this
> possible?
> Mirror only
> 
> zpool attach -f rpool c7t0d0s0 c7t1d0s0

Correct me if I'm wrong - This will only mirror the contents of the SOLARIS
partition.  It doesn't automatically mirror the partition tables or MBR.

Based on my experiences today, I need to format and create a partition 0
before the "zpool attach" will work.  And after it finishes resilvering, it
is smart to grubinstall the new disk, to ensure the newly created mirror
disk is bootable.



> One more question … Suppose I created a new volume:
>                 zpool create tank mirror c0t0d0 c0t1d0 mirror c0t2d0
> c0t3d0 mirror …
> Would this be a “stripe of mirrors” or would it be a “concatenation of
> mirrors?”  And would it be the same if I had started with a smaller
> set, and then did “zpool add tank mirror …” ???   It seems to me –
> since I’m capable of doing “zpool add” it must be a concatenation, and
> not a stripe.  Right?
> 
> You basically have two mirrors concatenated so your total disk space is
> the sum of both mirrors in the pool called "tank".

The reason I ask - just to be totally clear - 

There are two important differences between striping and concatenation.
(a) Performance.  Striping disks will perform better for large sequential IO
because it can utilize all the disks in parallel.  While concatenating disks
will perform better for small files (assuming they're at least 1 block in
size, and evenly scattered throughout all physical devices).
(b) Flexiblity.  You can't add disks to a stripe - although you might
concatenate to a stripe.  Striped disks must all match size.  But you can
easily concatenate mismatched disks, and continue growing with any new media
you acquire.


_______________________________________________
opensolaris-help mailing list
opensolaris-help@opensolaris.org

[prev in list] [next in list] [prev in thread] [next in thread]