* Migrating RAID 1 volumes to Dual ported disks.
@ 2009-11-03 16:01 Simon Jackson
2009-11-03 19:32 ` Goswin von Brederlow
0 siblings, 1 reply; 4+ messages in thread
From: Simon Jackson @ 2009-11-03 16:01 UTC (permalink / raw)
To: linux-raid
Hi.
I am currently using SATA drives in a RAID 1 configuration. I am looking to use SAS drives instead of SATA. As my first experiment I have plugged my SAS drive into a system and I have noticed that Linux sees the individual ports on the device as separate devices, so I have /dev/sdc and /dev/sdd which are both the same physical device.
So if I have a system with 2 SAS drives I am going to have 4 devices representing the two physical drives. So my question is how do I create RAID 1 sets for partitions on these types of drive?
My existing system carves 3 RAID 1 volumes from a pair of drives. How do I translate this to the dual port SAS devices?
Thanks Simon.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Migrating RAID 1 volumes to Dual ported disks.
2009-11-03 16:01 Migrating RAID 1 volumes to Dual ported disks Simon Jackson
@ 2009-11-03 19:32 ` Goswin von Brederlow
2009-11-04 15:24 ` Simon Jackson
0 siblings, 1 reply; 4+ messages in thread
From: Goswin von Brederlow @ 2009-11-03 19:32 UTC (permalink / raw)
To: Simon Jackson; +Cc: linux-raid
Simon Jackson <sjackson@bluearc.com> writes:
> Hi.
>
> I am currently using SATA drives in a RAID 1 configuration. I am looking to use SAS drives instead of SATA. As my first experiment I have plugged my SAS drive into a system and I have noticed that Linux sees the individual ports on the device as separate devices, so I have /dev/sdc and /dev/sdd which are both the same physical device.
>
> So if I have a system with 2 SAS drives I am going to have 4 devices representing the two physical drives. So my question is how do I create RAID 1 sets for partitions on these types of drive?
>
> My existing system carves 3 RAID 1 volumes from a pair of drives. How do I translate this to the dual port SAS devices?
>
> Thanks Simon.
You would set up multipath to combine the two paths to the same disk
as a single device and then run raid over that.
MfG
Goswin
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: Migrating RAID 1 volumes to Dual ported disks.
2009-11-03 19:32 ` Goswin von Brederlow
@ 2009-11-04 15:24 ` Simon Jackson
2009-11-05 2:02 ` Goswin von Brederlow
0 siblings, 1 reply; 4+ messages in thread
From: Simon Jackson @ 2009-11-04 15:24 UTC (permalink / raw)
To: goswin-v-b; +Cc: linux-raid
Sorry, I am probably being thick here, but do you mean something like:
mdadm --create /dev/md10 --level=multipath --raid-devices=2 /dev/sdc /dev/sdd
When I tried this I got:
# mdadm --create /dev/md10 --level=multipath --raid-devices=2 /dev/sdc /dev/sdd
mdadm: /dev/sdc is too small: 0K
mdadm: create aborted
#
-----Original Message-----
From: goswin-v-b@web.de [mailto:goswin-v-b@web.de]
Sent: 03 November 2009 19:32
To: Simon Jackson
Cc: linux-raid@vger.kernel.org
Subject: Re: Migrating RAID 1 volumes to Dual ported disks.
Simon Jackson <sjackson@bluearc.com> writes:
> Hi.
>
> I am currently using SATA drives in a RAID 1 configuration. I am looking to use SAS drives instead of SATA. As my first experiment I have plugged my SAS drive into a system and I have noticed that Linux sees the individual ports on the device as separate devices, so I have /dev/sdc and /dev/sdd which are both the same physical device.
>
> So if I have a system with 2 SAS drives I am going to have 4 devices representing the two physical drives. So my question is how do I create RAID 1 sets for partitions on these types of drive?
>
> My existing system carves 3 RAID 1 volumes from a pair of drives. How do I translate this to the dual port SAS devices?
>
> Thanks Simon.
You would set up multipath to combine the two paths to the same disk
as a single device and then run raid over that.
MfG
Goswin
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Migrating RAID 1 volumes to Dual ported disks.
2009-11-04 15:24 ` Simon Jackson
@ 2009-11-05 2:02 ` Goswin von Brederlow
0 siblings, 0 replies; 4+ messages in thread
From: Goswin von Brederlow @ 2009-11-05 2:02 UTC (permalink / raw)
To: Simon Jackson; +Cc: goswin-v-b, linux-raid
Simon Jackson <sjackson@bluearc.com> writes:
> Sorry, I am probably being thick here, but do you mean something like:
>
> mdadm --create /dev/md10 --level=multipath --raid-devices=2 /dev/sdc /dev/sdd
>
> When I tried this I got:
>
> # mdadm --create /dev/md10 --level=multipath --raid-devices=2 /dev/sdc /dev/sdd
> mdadm: /dev/sdc is too small: 0K
> mdadm: create aborted
> #
If sdc is 0k big then it doesn't look like that is your full disk.
MfG
Goswin
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2009-11-05 2:02 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-11-03 16:01 Migrating RAID 1 volumes to Dual ported disks Simon Jackson
2009-11-03 19:32 ` Goswin von Brederlow
2009-11-04 15:24 ` Simon Jackson
2009-11-05 2:02 ` Goswin von Brederlow
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.