topic Re: Getting the most total space out of an eva8000 in Disk Enclosures

Getting the most total space out of an eva8000

mujzeptu — Thu, 25 Sep 2008 22:11:41 GMT

I am looking at getting the most usable space out of an eva8000.

I have seen there is 1TB FATA disks, and this seems to be the best growth for the cost.

We currently have an eva8000 with 8 enclosures. They have the 146GB FC 15k disks in it currently. We are also soon to add an iSCSI connectivity option to it.

We are wanting to have 100 clients use iSCSI to get image files from the EVA over a GB network. About 30 clients will concurrently access the array to pull files ranging from 600MB to 5GB.

What upgrades or options should I look at?

Should we upgrade the controllers of the eva to 8100s? Should we upgrade to 4GB connectivity? More cache?

For the initial investment, what does it take (what do I need to purchase) to be able to add the FATA disks to my current environment? What enclosures, connectivity options, etc? Also is there a limit on how many FATA disks I can add? Can they co-exist with the FC disks?

Re: Getting the most total space out of an eva8000

IBaltay — Fri, 26 Sep 2008 04:23:18 GMT

Hi,
here are the docs which could help you:

EVA 4/6/8k iSCSI connectivity guide
http://bizsupport.austin.hp.com/bc/docs/support/SupportManual/c01519273/c01519273.pdf

EVA 4/6/8k Hardware config guide
http://bizsupport.austin.hp.com/bc/docs/support/SupportManual/c01364500/c01364500.pdf

EVA 4/6/8k User guide
http://bizsupport.austin.hp.com/bc/docs/support/SupportManual/c01492137/c01492137.pdf
here the FATA disks notes starts on page 39
and there is a following link:
http://h71028.www7.hp.com/ERC/downloads/5982-7353EN.pdf
FATA/SATA/PATA/FC disks comparison and notes

Re: Getting the most total space out of an eva8000

Steven Clementi — Fri, 26 Sep 2008 12:40:12 GMT

First... Keep in mind that FATA disks are NOT meant to be "online" 100% duty cycle. They are referenced as "Near-Online" storage.

Simply put, you can add FATA disks now to your EVA 8000. You do not need any more hardware than you already have, except of course if you do not have any available disk slots on your existing 8 shelves.

FC disks can co-exist with FATA disk in the same array, but NOT in the same disk group.

Whether or not you need to upgrade the EVA to an 8100 is best left to a Storage Assessment. Without knowing exactly what your storage is doing currently, there really is no way for someone to say "yes" you should upgrade or "no" it's not needed. (Unless you are talking to a sales person).

Steven

Re: Getting the most total space out of an eva8000

Timothy Cusson — Mon, 29 Sep 2008 14:53:44 GMT

The FATA disks are lowest cost per giga byte of any disk available for the EVA8x00. The reason is they are lower performance, and less reliable. You get what you pay for. I think they only spin at 5,400 RPM. They are designed for "Near Line" storage, not "Online" storage.

The 146 GB FC 15k disks you currently have are the highest performance and reliability.

As Steven said, you need a performance assessment to know how utilized your EVA is now, before you can determine if you need an upgrade. You can use EVAperf, doble click icon thenâ ¦

EVAperf> evaperf as -cont

To see your total I/O per second and total mega bytes per second. The iSCSI maximum is 1 Giga bit per second, due to Ethernet overhead, the actual maximum throughput is around 0.7 Giga bit per second, thus the bottleneck is the Ethernet network.

All you need to purchase is a minimum of 8 drives to be able to create a new disk group. FATA and FC disks cannot be in the same disk group. (As Steven said, as long as you have empty slots available).

If you don't have any empty disk slots (bays), then you will need to purchase a disk enclosure upgrade, which usually includes all the necessary cables. I believe the maximum number of disk drives for one EVA is 240, this requires to racks for a total of 18 disk enclosures.

As mentioned earlier, FATA and FC can coexist in the same EVA as long as they are in separate disk groups.

Regards,

Tim

Re: Getting the most total space out of an eva8000

mujzeptu — Mon, 29 Sep 2008 15:54:48 GMT

Ok great, thank you!

While I realize the fata disks are slower and less reliable, what does near online mean?

If this array is hardly hit performance-wise and is going to have say 20 users pulling a few GB files over iSCSI throughout the day, can fata handle that without the array being the bottleneck, minus the fact its not as reliable?

Re: Getting the most total space out of an eva8000

Uwe Zessin — Mon, 29 Sep 2008 16:06:39 GMT

'near online' suggests something "between":
'online (disk storage) and
'offline' (tape storage).

You should be fine with 20 users and a few GB, but you do realize that this is different from your original request?
""We are wanting to have 100 clients...
About 30 clients will concurrently access the array to pull files ranging from 600MB to 5GB.""

Re: Getting the most total space out of an eva8000

IBaltay — Mon, 29 Sep 2008 16:14:27 GMT

Hi,
in the article, which link I have posted in my 1st post, there is a good summary of the FATA disk usage

http://h71028.www7.hp.com/ERC/downloads/5982-7353EN.pdf

Re: Getting the most total space out of an eva8000

mujzeptu — Mon, 29 Sep 2008 16:53:38 GMT

Yeah, we will have a 100 total users. However at a time its probably max 20-30 users. They would be on a GB ethernet network using iSCSI targets on the array and SAN to copy files that are a few GB (max 6gb) in size.

Concurrently, it may even be as low as 5-10 users, but id say 20-30 is more accurate.

I just didnt know if fata would keep up with that. I would also probably make the most active users and targets on the FC disks, however to get the total storage I need affordably and right now, I would consider FATA.

I will go read the link in more detail now, thank you.

Re: Getting the most total space out of an eva8000

mujzeptu — Mon, 29 Sep 2008 18:08:25 GMT

Another quick question.

We have 4 loop-back switches right now with 2 eva8000 controllers and 8 disk enclosures.

If I wanted to add say another 2 disk enclosures, do I need to add anything else? Will 4 loop-back switches support 10 enclosures, or more? Any other cables or other accessories needed?

Re: Getting the most total space out of an eva8000

Steven Clementi — Mon, 29 Sep 2008 18:25:41 GMT

From the sound of it, you can probably reliably run FATA disks and not have any issues.

The 4 loop switches should be able to handle at least 1 full EVA rack (12 shelves) as well as 6 shelves in an expansin rack. The shelves come with cables to connect to the switches, as well as a CAN bus cable to attach the shelf's EMU to the cabinet bus.

Steven

Re: Getting the most total space out of an eva8000

IBaltay — Mon, 29 Sep 2008 18:28:02 GMT

>We have 4 loop-back switches right now with >2 eva8000 controllers and 8 disk >enclosures.

its the max for EVA 8000 for the single rack and also for the double rack config, (max disk enclosures for the single rack is 12)

see
http://h18006.www1.hp.com/storage/disk_storage/eva_diskarrays/eva_arrays/index.html

>Any other cables or other accessories >needed?

as spoken there is the following accessories from HP to be used with each enclosure...

http://partsurfer.hp.com/cgi-bin/spi/main?sel_flg=partinfo&template=main&cpric=&ps
rchmode=&partsrch=336881-B21&submit.x=7&submit.y=4

Re: Getting the most total space out of an eva8000

mujzeptu — Mon, 29 Sep 2008 21:36:56 GMT

So I only have room for 3 more enclosures in this rack....

There is the two controllers, the 4 loop-backs, the 8 enclosures AND a 1U iscsi kit.

This leaves me with 1U short of space of adding the 4th and 12th total enclosure.

Now, when you move to another rack, what does this mean? Are you just physically putting the new enclosures in another rack? Is there cable length issues and connectivity issues with cabling? Is there anything additional needed to make it work?

With the 4 loop-back switches we'd like to now go up to 12 enclosures, but not sure if having more enclosures in another rack causes new issues or needs...

Re: Getting the most total space out of an eva8000

Steven Clementi — Tue, 30 Sep 2008 03:36:43 GMT

The EVA 8x00 is expandable to 18 shelves. !2 in the Controller rack and 6 in an expansion rack. The Expansion rack is a standard HP Rack.

My suggestion is...

... move the iSCSI gateway to anther location to make room for the 12th shelf.

The problem you will run into with having the 12th shelf in another rack is that you will need to either get a longer CAN bus cable, or get a kit to extend the bus into the next rack. The Expansion rack usually sits right next to the EVA rack. The cables are long enough to make it to the backend loop switches if the shelves are right next to the EVA.

Steven

Re: Getting the most total space out of an eva8000

Tom O'Toole — Tue, 30 Sep 2008 16:00:28 GMT

The FATA drives are 7200 rpm, and transfer rates are very high, because the density is very high. Anyway 30 users does not sound like a very high load for an eva 8000. It sounds like you are mostly looking to get more data capacity.

As mentioned you will need to buy at least 8 to create a disk group. A small disk group provides less usable space per disk, because of per-disk group overhead, so maybe try to buy more than that, in multiples of 8.

For managing this, you may want to try move less active, but large data to the FATA disk groups vdisks, so less IO/S are done there.