Eva4400 raid10 vdisk capacity upgrade

[Jan Soska]

Hi all,
we have older EVA6000 array and think of buing new EVA4400. We plan use 1 disk group with 24 450GB 15K FC drives, then use only raid10 vdisks for specific reason.

We need to estimate future cost for upgrading.

Lets imagine situation in future: We want to upgrade available disk space for raid10 vdisk by ~1TB.
IS it enough to buy 3x450GB 15K FC drives - teoretically 1,35TB disk space - or we need even number of new disks - at least 4x450GB for 0,9TB or better 6x450GB for 1,35GB ?

As we know our old Eva6000, raid10 vdisk are spread only on even number of disks in disk group so raid10 space for vdisk is "limited" so we need to buy disk in even numbers (ideally in 8's)

Is there any change in newer controller HSV300 in Eva4400?

Many thanks for hints / ideas / discusion.

Jan

[Steven Clementi]

"IS it enough to buy 3x450GB 15K FC drives - teoretically 1,35TB disk space - or we need even number of new disks - at least 4x450GB for 0,9TB or better 6x450GB for 1,35GB ?"

The same concept still exists:

You can add "any" number of disks into a disk group up to the max. It would be "best" to add disks in groups of 8, but it would also be ideal to have 8 disk shelves when doing so. It is not likely that you will start off with 8 disk shelves.

afaik, the actual storage of data is still the same...

sc

[Jan Soska]

Hello Steven, we plan to start with 4 enclosures.

Anyway - do I understand you correctly and my "old fashion" idea/experience is valid - we have to buy even number of disks to disk group to raise capacity of raid10 vdisk?

Thanks

[Uwe Zessin · Accepted solution]

VRAID-1 data is always stored on "disk pairs". When you have a diskgroup with an odd number of disks (9,11,...) and you only create vdisks in VRAID-1 .... one of the disks is not used to store any data -- because it does not have a partner for the mirrored data!

[Johan Guldmyr]

Yeup, the "uneven" disk would only be used for vraid0/5/6 disks.

[Jan Soska]

Thanks all for verification.

[Jan Soska]

EVA raid10 vdisks need even number of disk in disk groups.