Which RAID set and which disk types to choose?

seiern

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Mar 18, 2014
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Hi there, hope you can help us with some advice!

We are migrating our Magento installation (eCommerce) from VPS to dedicated server and hoping for some advice when it comes to the RAID setup and which HD types to use. We have received some advices that we should run database on SSD drives and the rest on SAS disks.

8x 2.5” drive bays available, which HD type/configuration?
RAID supported: 0, 1, 1+0, 5, 5+0, 6, which RAID setup?

Here are some suggestions to RAID setup and disk types that we have received so far:

2x SSD RAID 1 / 120GB (Intel® SSD 530 Series 120GB 2.5")
6x SAS RAID 10 / 10K 450GB

2x SSD RAID 1 / 120GB (Intel® SSD 530 Series 120GB 2.5")
6x SAS RAID 10 / 15K 146GB (Ideally I would like 300GB 15K, but they are really expensive)

4x SSD RAID 10 / 120GB (Intel® SSD 530 Series 120GB 2.5” Serial ATA-600)
4x SAS RAID 10 / 10K 450GB

Our server:
Processor(S) 2x Intel Xeon X5670 (2.93GHz/6-core/12MB/95W) Processor Kit
Memory 48GB
Hard Drives NO HDD
Drive Bays 8x 2.5” SFF DRIVE BAYS AVALIABLE
Raid HP Smart Array P410I CONTROLLER
Graphics INTEGRATED ATI ES1000, 32MB
Optical Drive(s) DVD Rom
Power Supply(s) DUAL POWER SUPPLY
Rail kit Rail kit Included
Features List DVD, Intel GB NIC, USB

Our Magento installation
Magento 1.8.1.0
mySQL Ver 14.14 Distrib 5.5.28, for debian-linux-gnu (x86_64) using readline 6.2
Ubuntu 12.04.1 LTS (GNU/Linux 3.2.0-34-generic x86_64)
Nginx
PHP-FPM
PHP 5.4
var/cache and var/session on ramdisk

We would also use Varnish, memcached /APC, but we are still in developer mode. We appreciate all replies.
 


Well I can't really answer this question without knowing the expected size/load on the database will be and how much data on the secondary storage you will need to support.

It would also be good to know what backup scheme you're using behind this, because there will be some differences in the reliability/availability of a RAID 1 vs RAID 10 setup for consumer SSD's.
 


Just talked to our developer and we would not need more than this:
Database 20GB
Files 400GB

We use Amazon S3 cloud backup.

Some additonal question, should we split the media files and the OS files on two RAID set? Do you also recommend using 15K disks? We are open for all suggestions, thanks in advance.
 


From a cost vs performance standpoint you'll be gaining very little in terms of transfer speeds but significantly(20-30%) in terms of access time with 15k drives. So if your priority is supporting a larger number of concurrent users, then I would go with 15k drives.
There won't be any significant improvement in terms of performance on a database that small with RAID 10.

I would say option 2 is your best bet, with option 1 being a close second if cost is a higher priority than maximizing concurrent access performance.

I would also suggest you may want to invest in at least another dedicated physical backup in your possession, even if it is as simple as a single external drive.

Amazon is a 99% uptime service and ultimately you don't have any kind of data loss guarantee on the cloud any more than on disk, so be wary of that.