Re: possibly silly question (raid failover)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 02/11/2011 07:02, keld@xxxxxxxxxx wrote:
On Wed, Nov 02, 2011 at 12:48:16PM +1100, NeilBrown wrote:
On Wed, 2 Nov 2011 02:37:56 +0100 keld@xxxxxxxxxx wrote:

On Wed, Nov 02, 2011 at 09:25:26AM +1100, NeilBrown wrote:
On Tue, 1 Nov 2011 23:15:39 +0100 keld@xxxxxxxxxx wrote:

On Tue, Nov 01, 2011 at 04:13:26PM -0400, Miles Fidelman wrote:
David Brown wrote:
No, md RAID10 does /not/ offer more redundancy than RAID1.  You are
right that md RAID10 offers more than RAID1 (or traditional RAID0 over
RAID1 sets) - but it is a convenience and performance benefit, not a
redundancy benefit.  In particular, it lets you build RAID10 from any
number of disks, not just two.  And it lets you stripe over all disks,
improving performance for some loads (though not /all/ loads - if you
have lots of concurrent small reads, you may be faster using plain
RAID1).
In fact raid10 mas a bit less redundancy than raid1+0.
It is as far as I know built as raid0+1 with a disk layout
where you can only loose eg 1 out of 4 disks, while raid1+0
in some cases can loose 2 disks out of 4.
With md/raid10 you can in some case lose 2 out of 4 disks and survive, just
like raid1+0.
OK, in which cases, and when is this not the case?

best regards
keld
"just like raid1+0"
No, that is not the case AFAIK. Eg the layout of raid10,f2 with 4 disks is
"just like raid0+1".

Isn't md raid10 n2 exactly the same as RAID1+0??
--
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


[Index of Archives]     [Linux RAID Wiki]     [ATA RAID]     [Linux SCSI Target Infrastructure]     [Linux Block]     [Linux IDE]     [Linux SCSI]     [Linux Hams]     [Device Mapper]     [Device Mapper Cryptographics]     [Kernel]     [Linux Admin]     [Linux Net]     [GFS]     [RPM]     [git]     [Yosemite Forum]


  Powered by Linux