How to calculate IOPS on EVA 4400 with Eight 400GB 10K RPM disk drives

[Eric_371]

Hello, We are planning to buy a new EVA 4400 wiht Eight 400GB 10K RPM disk drives and i'm searching how to calculate the possile IOPS with this configuration:

HP EVA4400 Starter Kit 400GB 10K Field Installed
EVA4400 Dual Controller array
M6412 12-bay HDD enclosure
Command View EVA V8.0 Media CD and 4-1 TB License
SmartStart for HP EVA Storage
XCS 9.0 Firmware
Eight 400GB 10K RPM disk drives

We are planning to use these EVA with C7000 enclosure with 4 Blades BL460c to host the VMware ESX 3.5 Server VMs (12 guest VM)

The HP ESX Sizer give a configuration with 32 HD and i searching why so much hard drive ?? It's a Performance issue ?? The total IOPS for all servers that we are using is currently about 8000 iops TOTAL. the Big question is: Is the EVA configuration (see at the top)is enought to achieve 8000 IOPS ?

[IBaltay]

hi,
i am sending you the eva 4400 performance document:
http://spywareguide.tradepub.com/free/w_hp42/pf/w_hp42.pdf
In disk oriented storages such as EVA, the main perf rule is the more physisal disks/spindles in the disk group (pool) the more performance

[Patrick Terlisten · Accepted solution]

Hello,

there is a simple rule:

More disks = more IOPS.

You can calculate with round about 200 IOPS for a 15k drive, and round about 150 IOPS for a 10k drive. MB/s are IOPS x IO Size. If you need more MB/s, you need more IOPS. Depending in the RAID level you will get more or fewer IOPS. If you're using RAID 5, you will get only 25% if you're doing a write IO.

Depending on my above written IOPS, you will need round about 50 drives. But performance is depending on so much values.... Number of disks, RAID level, applications, avg. IO size and some more.

Best regards,
Patrick

[Víctor Cespón]

As Patrick says above, until we can have SSD disks on the storage systems, the mechanical disks are limited to less than 200 IOPS per disks (here we use a more conservative 170 for 15K, 120 for 10K and 80 for SATA). So just divide 8000 by the IOPS per disk and you'll get how much disks you need.
Also it's important if that's the average or peak IOPS, the EVA has a big cache and can handle spikes of thounsands of IOPS, it stores them on the cache and later flushes the data to the disks.

[Eric_371]

if we plan to use VMWare ESX 3.5 with this configuration, because VMWare execute a lot of information directly into the memory of BL460c (32GB RAM / Blade) Do you think we'll always get the total 8000IOPS tha we arrive on our servers physical or we can expect less IOPS?

[IBaltay]

Hi,
Maybe the VMware3/HP StorageWorks best practice document helps you
http://h71019.www7.hp.com/ActiveAnswers/downloads/VMware3_StorageWorks_BestPractice.pdf

[Uwe Zessin]

ESX does NOT cache any disk I/O - it directly passes the I/O from the virtual adapter to the physical LUN. So you cannot expect any increases on I/O throughput when using ESX (if there are any - they come from somewhere else, e.g. a more powerful platform than the old physical system).

[Digex]

We currently have 40 300GB 10k disks in EVA4100. We do a restore via tape backup and it slows the entire EVA down to a crawl. Is this because it cannot handle the sequential write I/O? During the restore it says 7,000kb/s 3500 IOPS in San Surfer. After reading your pdf Im not sure why it says vraid 5 sequential write is 256.

[IBaltay]

Hi,
here is the EVA config best practices:
there is a section "Best practices to optimize the performance" there:
http://h71028.www7.hp.com/ERC/downloads/4AA0-2787ENW.pdf

Maybe some ideas can be filter out also from a)the Backup/recovery best practices for an ultra large Oracle database white paper , though it is true that it is for the HP-UX
http://h71028.www7.hp.com/ERC/downloads/4AA0-4661enw.pdf

and/or

b)the Backup and recovery best practices for Microsoft Exchange
http://h71028.www7.hp.com/ERC/downloads/4AA1-6077ENW.pdf

[Eric_371]

You can calculate with round about 200 IOPS for a 15k drive, and round about 150 IOPS for a 10k drive. MB/s are IOPS x IO Size. If you need more MB/s, you need more IOPS. Depending in the RAID level you will get more or fewer IOPS. If you're using RAID 5, you will get only 25% if you're doing a write IO.

Depending on my above written IOPS, you will need round about 50 drives. But performance is depending on so much values.... Number of disks, RAID level, applications, avg. IO size and some more.