adding FC drive enclosure to EVA8400

[Albator]

Hi,

We have an EVA 8400 with 12 drive enclusures FULL of FC hard drives. There is room for expansion. We want to add FATA disks on the EVA so we need to also add disk enclosures since all enclosures are FULL of fast FC drives. What's the minimum number of enclosure required to add fata disks and create a new DiskGroup? We need minimum 2 enclosures since 9 TB of usable disk space is required (approx. 14x1TB drives with protection level 1 and VRAID 5). Not sure if more than 2 disk enclosures are required for the EVA to have proper redundancy for the new disk group.

Thank you

[Steven Clementi]

I have an EVA4400 where I added 2 disk shelves and created a new disk group out of the disks in those shelves, 12 disks total if I remember correctly. No problems.

That said, I think you'd be fine if you added a minimum of 2 shelves.

Yes, the Controllers are slightly different, but they run the same XCS. Someone will likely confirm.


Steven

[hvhari]

hi,

yes you can create new Disk group consisting only FATA disks from the two new enclosures. Please note that FATA disks have different characterestics than FC disks.

You can read the best practices guide at below link for better understanding.

ftp://ftp.compaq.com/pub/products/storageworks/whitepapers/5982-9140EN.pdf

[Greybeard]

just remember that if you do it the easy way (all new disks in two extra enclosures) you will not have low level resiliency across RSSs. Idealy you want to identify the RSS groups and move the existing disks to include the new enclosures then put the new disks across all enclosures. This way no two disks from a single RSS will be in the same enclosure.

[Proliant VMS San Mgrs]

We did something similar, with an EVA 6000. Initially, we had 4 shelves, with 32 disks, as a single group. We eventually added 24 larger disks, as a second group; we were not willing to install 4 additional shelves at that time. With a total of 56 disks, the 4 shelves are now full with the two groups.

Best practice, IIRC, is to have at least 8 disks in an RSS, spread over the largest possible number of shelves.

We did a complete shutdown for this work, although it is conceivable you could do this by hot swapping drives around. Not for the faint of heart, and not a strategy I would recommend.

Plan for an outage if that is possible.

[charles yoakum]

Adding 2 enclosures is a good start.
You should make the new FATA group with the new Drives over all 14 enclosures in a line as in all FATA in the last slot on the left. This will give you the redundancy you will need. Just adding 2 enclosures and putting in all the FATA drives into it will not make your EVA FATA disk group as protected as it will need to be.
You have the methods.
1) Shutdown and move your drives. This is preferred. Do not worry about the data on the drives the EVA numbers each of the drives and when it comes up it will see the drive number is in a different enclosure, slot and the EVA will be happy.
2) If you have room in the FC disk Group you would down 1 drive in the position you want and then let it level. This can take 1-3 days per drive. Then move the drive and put in the FATA drive remember you must have 8 FATA drives before you can make a new FATA Group. This takes a long time.
3) Would to do this hot and pop out 1 FC drive where you want the FATA drive to be and then move the FC drive to an empty slot in under 3 min's. If you do then the EVA should see the drive catch it up the mirror one and level it fast. If you do it over that then the drive will need to be rebuilt (EVA disk auto should do this) this is not for the faint hearted, I know only 1 guy to have done this. I have done the 1st and the 2ed ways. The 3rd one is a bit too risky for me.
Remember to make your drive groups in a vertical not a horizontal in other words not all on 1 enclosure but over all enclosures.

You will need to add the two enclosures I prefer to do this with the EVA down but you can do it hot. I have done both. I much prefer the cold EVA. Have your cables and lay out setup and do not for get to balance your loops.

good luck, your HP Eng. can do the enclosures install but I prefer to do it all myself.

good luck, remeber if you need help or have a question call HP EVA support before you do it. plan it out and use the HP EVA install guides.