SQL Server Performance Forum – Threads Archive

What is RAID 1+0 ?

Hi my understanding is that RAID 1+0 is first mirrored and then striped physical drives.
And if I understood correctly I have to have 4 physical disk as minimum to accomplish RAID 1+0 I understand the theory (I think) but I every time when I try to configure RAID Array using HP configuration utility and choose
2 physical drives for my array – I will only have options to create RAID 0 or RAID (1+0) I don’t think this is my "expensive" RAID that I try to create for my ldf or mdf files. but choosing 4 physical drive will give me the very same options – so I don’t really know how to create RAID 10(1+0) If someone can just share own practical experiance on how I can create this type of array – it would be greatly apprectiated. thank you

if you select 2 drives
the vendor software program should give you RAID 0 or RAID 1 options if more than 2, it should give options RAID 0, 5 or 10
10 might require an even number of drives, depending, read the screens more carefully
also, it really does not matter if it says RAID 1 or 10
your data is mirrored instead of parity checked it might be safe to assume the RAID vendor knew what they meant,

i would expect that to do whatever you saing , but it is not happening
1.
According to HP when I choose 2 physical drive I have only 2 options in dropdown box RAID 0
RAID 1+0 2.
If I have 3 physical drives it will tell me RAID 0
RAID 5 3.
4 physical drives: RAID 0
RAID 1+0
——————————- I did try to read options very carefully.

then RAID 1+0 with disks is just RAID 1,
some one apparently was too lazy to add separate entries for 1 and 1+0
don’t worry about that that is does not support RAID 5 with disks is silly
which controller are you on?

It does support raid 5 – if I choose 3 or 5 disks it will let’s me create raid 5 What I am confused about : if I choose 2 phys. disk I have options for RAID0 and Raid 1+0
and when I choose 4 disks I again have very same options : raid 0 and raid1+0.
That ‘s it. Is that means whatever they call 1+0 raid – it is not that 1+0 raid that I am looking for? I guess so. So how do I really create RAID 10. Are you saing that some controllers would basically not support some raid configuration ?
My controller is= MSA500 G2 CONTROLLER IN MA27MT4269

DP NOT WORRY about whether it says: RAID 1 and RAID 1+0 in essence, you get mirroring for data protection
if you have 4 or more disks, you get stripping for performance what is stupid about the controller is that you do not have the RAID 5 option for 3 or more disks, including 4,
there is no reason you cannot do RAID 5 on 4, or other even number of disks (>2) i think the person who did the program goofed
or something it is amazing that this is an HP controller
they have been doing this for a long time

O , I see – well now I understand RAID 10. But what if I what to create RAID 0+1 instead of RAID 1+0 ? I guess I cannot. So truly – I can only choose between RAID 0, 1(2disks), 5(uneven number of disks) and 10 (even Number of more then 4 disks) No other RAIDS allowed. Hm-m-m-m Still – thank you very much ,joechang, you did helped a lot I was totally lost with this thing. <img src=’/community/emoticons/emotion-1.gif’ alt=’

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nitwits talk about RAID 0+1 vs RAID 1+0
the first, in theory, implements a RAID 0 stripe, then mirrors it,
if you lose 1 disk, the entire stripe goes down but the hardware is blind to this theoretical differnce between 0+1 and 1+0
it makes no difference in fact, no (reputable) HW vendor should not be doing anything stupid
so there is no point fretting whether it is 1+0 or 0+1

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