[CentOS] Re: Anaconda doesn't support raid10

[Ruslan Sivak]

John R Pierce wrote:
> Ruslan Sivak wrote:
>> John R Pierce wrote:
>>>
>>>>
>>>> Yes, if two disks belonging to the same mirror go down, I lose my 
>>>> data.  But if two disks which are not from the same mirror go down, 
>>>> I would like to be able to boot up without any problems.  And as 
>>>> someone else mentioned, what else am I going to do with those 
>>>> 200mb?  I'd rather maintain symmetry and not have to worry which 
>>>> disks /boot is on, as I'll know that if the data drive survives, 
>>>> then I won't have any problems with the boot drive either.
>>>
>>> so, is your / on a 4 spindle mirror too?
>>>
>>>
>>>
>>> N-way mirrors require every write to be done N times.
>>
>> No, / is on a 2 raid 1 arrays which are striped using LVM.  And the N 
>> times write penalty doesn't really apply to boot, since it rarely 
>> gets written to.
>
>
> so, if the LVM  is built from the 2 raid1 sets md1 and md2, and both 
> drives of md1 are down, its down.   ditto if both drives of md2 are 
> down.   so why not just put the /boot on the same spindles as md1 ?
>
> btw, LVM isn't really striping, its more like globbing. or scattering.

Well the reason not to put /boot on the same spindles as md1 has already 
been mentioned a few times.  Basically flexibility. 

What do you mean LVM doesn't really do striping?  What does globbing 
mean?  Does it mean there is no performance difference between striping 
LVM and just concatenating 2 raid1's?

Russ