EVA 5000 supports raid 0+1?

[ramon_17]

In technical manuals says that eva supports vraid0,vraid1 and vraid5,

my question is if the eva 5000 supports raid 0+1 ?

[Hein van den Heuvel]

Yes. It is implied.

The EVA _always_ stripes over multiple disks in a diskgroup to make Virtual Disks.
It can add mirroring to that, affectively making it 0+1, it calls that vraid1.
The EVA will never present a 'Plain Old Disk' (POD?) and so it never does a raid-1.

I suppose that the V in Vraid1 signifies this.

hth,
Hein.

[ramon_17]

In this case I suppose that the eva it cannot be only formed in raid 1, that its correct?

[Hein van den Heuvel]

Correct. Like I wrote earlier.
What would you like plain 'raid-1' to mean?
A simple single disk, with a one or more other simple disks maintaining mirror copies of it's data? Not going to happen on an EVA.
You Group the physical disks and the EVA will create Virtual disks from 'physical' chunks of the group, creating as many copies as needed and making sure the copies live on different disks, minimizing the failure risk. A single failed disk will not cause Virtual disk failure, and it also attempt to protect against multipel disk failures if the group is large enough.

Admittedly I have also looked for, and requested from Engineering, simple raid-1, possibly implemented by allowing 2 or 3 member groups. IMHO such devices would e valuable for linear-write applications such as Oracle redo-logs. It doesn't look like we are going to get that.

Hein.

[ramon_17]

Thanks a lot Hein,