zfs discuss - May 2010 - 3 Data Disks: partitioning for 1 Raid0 and 1 Raidz1

Hello,

I want to slice these 3 disks into 2 partitions each and configure 1 Raid0 and 1
Raidz1 on these 3.

What exactly has to be done? Using format and fdisk I know but not exactly how
for this setup.

In case of disk failure: how do I replace the faulty one?

Thank you for a great product

Jason
-- 
This message posted from opensolaris.org

On 05/15/10 09:43 PM, Jason Barr wrote:
> Hello,
>
> I want to slice these 3 disks into 2 partitions each and configure 1 Raid0
and 1 Raidz1 on these 3.
>
>    
Lets get the obvious question out of the way first: why?

If you intend one two way mirror and one raidz, you will either have to 
waste one slice, or have two slices from the same drive on the raidz, 
which isn''t a good idea.

What is your goal?

-- 
Ian.

Hi,

something like this

Disk #	Slice 1	Slice 2
1		raid5		raid0
2		raid5		raid0
3		raid5		raid0

I want to have some fast scratch space (raid0) and some protected (raidz)

Greetings

J
-- 
This message posted from opensolaris.org

----- "Jason Barr" <forum4guy at arcor.de> skrev:
> Hi,
> 
> something like this
> 
> Disk #	Slice 1	Slice 2
> 1		raid5		raid0
> 2		raid5		raid0
> 3		raid5		raid0
> 
> I want to have some fast scratch space (raid0) and some protected
> (raidz)
Should be doable - make sure the raid0 is on the first slice, though - drives
have more sectors on the outer cylinders than on the inner ones, and are
therefore fastest at the "beginning" of the drive. The difference is
about 1:2 comparing outer rim and inner, although space-wise, the curve is not
linear, since most of the data is stored in the outer parts (due to more sectors
per cylinder there).

Best regards

roy
--
Roy Sigurd Karlsbakk
(+47) 97542685
roy at karlsbakk.net
http://blogg.karlsbakk.net/
--
I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er
et element?rt imperativ for alle pedagoger ? unng? eksessiv anvendelse av
idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og
relevante synonymer p? norsk.

Ok,

I got it working: however I set up two partitions on each disk using fdisk
inside of format

what''s the difference to slices (I checked with gparted)

Bye
-- 
This message posted from opensolaris.org

----- "Jason Barr" <forum4guy at arcor.de> skrev:
> Ok,
> 
> I got it working: however I set up two partitions on each disk using
> fdisk inside of format
> 
> what''s the difference to slices (I checked with gparted)
Both are supported, but from another post in here recently, it seems fdisk
partitions aren''t automatically recognized if moving a port, while
slices are. I think you should change that to slices.

Best regards

roy
--
Roy Sigurd Karlsbakk
(+47) 97542685
roy at karlsbakk.net
http://blogg.karlsbakk.net/
--
I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er
et element?rt imperativ for alle pedagoger ? unng? eksessiv anvendelse av
idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og
relevante synonymer p? norsk.

On Sat, May 15 at  2:43, Jason Barr wrote:
>Hello,
>
>I want to slice these 3 disks into 2 partitions each and configure 1 Raid0
and 1 Raidz1 on these 3.
>
>What exactly has to be done? Using format and fdisk I know but not exactly
how for this setup.
>
>In case of disk failure: how do I replace the faulty one?
I think this is a bad idea.  Spreading multiple pools across the
partitions of the same set of drives will mean accesses to both pools
will have lots of extra seeks going from one portion of each drive to
the other.

If you are trying to get redundancy on a system without many disks,
i''d just mirror the root pool and put your data in there as well.  At
least that way, you won''t be seeking across partitions.

Another option is to have a single boot drive, and a mirror of drives
for your data pool.  That''s effectively how we do it at work, since
our SLA for system recovery allows a reinstall of the OS, and the
amount of custom configuration is minimal in our rpool.


-- 
Eric D. Mudama
edmudama at mail.bounceswoosh.org