Re: Grow a RAID-10

["Daniel L. Miller" <dmiller@xxxxxxxxx>]

Keld Jørn Simonsen wrote:
> On Wed, Jul 02, 2008 at 02:56:04PM -0700, Daniel L. Miller wrote:
>   
> > I currently have a RAID10 across (4) SATA drives.  It looks like I'm 
> > going to need to grow in the near future.  Any tips for a procedure for 
> > this?  My current plan:
> >
> > 1.  Add a PCI SATA controller (MB had 4 SATA + 4 RAID SATA, it's a Tyan 
> > MB with a NFORCE chipset, I'm not sure if I want/can use the RAID SATA 
> > ports as plain SATA connections).
> >     
>
> Why not use the mobo raid sata ports? They are probably faster than a
> controller on the pci bus. What kind of pci bus do you have?
>
>   
My mistake.  Confused this one with another system.  Only have 4 ports 
available.  I did have the option of using the Nvidia RAID - which I did 
NOT enable.

What "kind" of pci bus?  Don't understand the question.  If it matters, 
it's a Tyan S2892, a "Thunder K8SE".  nForce Pro2200 and AMD8131 PCI-X 
chipsets.
> PCI-E 1x is likely to be too slow for a 4-drive raid10,f2 array.
> My 4-drive raid10,f2 delivers about 320 MB/s and newer disks should be
> able to deliver 360 MB/s - well above the 250 MB/s that a PCI-E 1x can
> deliver. 
>
>   
> > 2.  Add 2 more drives - not necessarily the same size as the existing 
> > (they were all 4 the same)
> >
> > 3.  Execute "mdadm --grow /dev/md0"
> >     
>
> What kind of raid10 do you have?> 
>   
I don't understand this question either.

mdadm --detail /dev/md0
/dev/md0:
       Version : 00.90.03
 Creation Time : Tue Oct  3 19:11:53 2006
    Raid Level : raid10
    Array Size : 312581632 (298.10 GiB 320.08 GB)
 Used Dev Size : 156290816 (149.05 GiB 160.04 GB)
  Raid Devices : 4
 Total Devices : 4
Preferred Minor : 0
   Persistence : Superblock is persistent

   Update Time : Wed Jul  2 18:46:15 2008
         State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
 Spare Devices : 0

        Layout : near=2, far=1
    Chunk Size : 32K

          UUID : 9d94b17b:f5fac31a:577c252b:0d4c4b2a
        Events : 0.10941692

   Number   Major   Minor   RaidDevice State
      0       8        0        0      active sync   /dev/sda
      1       8       16        1      active sync   /dev/sdb
      2       8       32        2      active sync   /dev/sdc
      3       8       48        3      active sync   /dev/sdd

--
Daniel
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html