Oliver Ransom wrote:
> On 31/08/2009, at 1:11 PM, Christopher Chan wrote:
>
>
>> Miguel Medalha wrote:
>>
>>>> Can someone please assist met with some software RAID 1+0 setup
>>>> instructions? I have searched the web, but couldn't find any. I
>>>> found
>>>> a lot of RAID 10 setup instructions, but it doesn't help me.
>>>>
>>>>
>>>>
>>> As Oliver Ransom replied to you, RAID 1+0 (not to be confused with
>>> RAID
>>> 0+1) is RAID 10. mdadm has direct support for RAID 10. I am using
>>> it on
>>> CentOS 5.3 and it works really well.
>>>
>>>
>> RAID 1+0 is NOT RAID 10. raid 1+0 is achieved using the combination of
>> raid1 and raid0 personalities. Raid10 is a different animal and has
>> its
>> own personality. (personality as reported by 'cat /proc/mdstat' aka md
>> modules)
>>
>> raid10 was only introduced in 2.6.9 and Oliver's link clearly shows
>> that
>> it is 'Non-standard' or not raid1+0.
>>
>
> RAID 10 and 1+0 are referred to interchangeably in the
> Nested_RAID_levels article, "RAID 1+0, sometimes called RAID 1&0, or
> RAID 10".
>
> I'm a bit confused now!
When it comes to Linux software raid, the raid10 module does things
differently from what you get from a combination of raid1 + raid0. When
it comes to hardware raid, raid10 is very likely to mean raid1+0.
The problem is that that chum behind the raid10 module chose a name that
was not at that time strictly defined and people would use raid10 in
their articles to mean raid1+0. The raid10 module can do something
similar to what you get with raid1+0 but it can also do completely
different things in the way it handles data. You can for example have
three disks and get a 'raid10' array. You do not have to have an even
number of disks to create a 'raid10' device with the raid10 module.
http://neil.brown.name/blog/20040827225440
BTW, the raid10 module does not have the same reputation as the raid1
and raid0 modules...even the raid5 module did not have a good reputation
five years ago sometime around when raid10 was introduced and the raid5
module has been around for some time then.
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
