Can 1 or 2 x SSD's be set to 2,3, or 4 partitions to benefit from any raid array configuration ? ( ie: RAID 0,1,2,3,4,5,10 ?

landcruiser

Reputable
Aug 8, 2014
2
0
4,510
Hi, I have an Alienware XPS System i7 820 or 920CPU w/12G Ram & I have been considering the pros & cons of the different RAID configurations, many as there are! My system has 2x1Tb 7200 Seagates in RAID0 as my OS & I have 2 x SSDs, 1 is a 250 Gb Samsung 840 series, & the other a C300 Micron 128Gb. I do a lot of DVD editing & quite a stack of drives I am trying to clean up & organise a bit better. I have about 6x 500G 2.5 HDDs, 3x640G 5400rpm, 2x1.5Tb WDs 7200rpm & the above SSDs + 1x OCZAgility3 240Gb that has never worked from new. ( I am hoping I might be able to re flash it somehow & get it working one day to add to something. I recently got a Nexstar 4bay hot swappable RAID Tower, think I might JBOD some of them here maybe.
Q1. Can I split the partition of the Samsung to get 2x125Gb on one drive for a RAID0 &/or 1setup?
Q2. If so, could I then use the 128 as a 125G drive in series with the Samsung RAID0 ?(3x125Gb)
Q3. If Q1 is so, can I split the 128G into 2x64Gb Partitions as RAID0 & Samsung as RAID1? To get some extra speed & speedy redundancy, & then maybe backup to 2x external HDDs, mirrored data on each but not as RAID configuration for extra redundancy.
Thanks for any help, thoughts or answers to these questions in advance.

 
Solution
RAID configurations are "whole hard drive" - it takes all drives that are assigned to create the array. You can split arrays, but you can't split hard drives via partitions to create "virtual RAID".

I have built quite a few RAID arrays in production environments, it is always best practice to utilize same size drives in a RAID array....and better if they are the same make/model drives.
Q1: No, you cannot RAID partitions only the full drive, with another drive. (Strongly recommend using the same model drive, and I advise against RAIDing SSD's)
Q2: No. Again you need seperate drives not partitions.
Q3: No.

If I were you I would leave the SSD's alone, and do a RAID 5 on the 6x 500GB, Then another RAID 5 on the 3x 640GB. and a RAID 1 on the 2x 1.5TB.
Also do not use the Windows RAID utility, and with this many drives I doubt your Intel Chipset RAID controller has enough SATA ports to do all of these arrays in which case you will need a separate RAID controller.
 
RAID configurations are "whole hard drive" - it takes all drives that are assigned to create the array. You can split arrays, but you can't split hard drives via partitions to create "virtual RAID".

I have built quite a few RAID arrays in production environments, it is always best practice to utilize same size drives in a RAID array....and better if they are the same make/model drives.
 
Solution
Wow! you have quite a mess.

Here is where I think you should be heading to:

1. Use a SSD for the "C" drive. A ssd is very fast in random I/O, and that is what the os does 90% of the time.

2. Abandon raid-0.
Raid-0 has been over hyped as a performance enhancer.
Sequential benchmarks do look wonderful, but the real world does not seem to deliver the indicated performance benefits for most
desktop users. The reason is, that sequential benchmarks are coded for maximum overlapped I/O rates.
It depends on reading a stripe of data simultaneously from each raid-0 member, and that is rarely what we do.
The OS does mostly small random reads and writes, so raid-0 is of little use there.
There are some apps that will benefit. They are characterized by reading large files in a sequential overlapped manner.

3. Develop a backup plan.
The value of raid-1 and it's variants like raid-5 is that you can recover from a drive failure quickly. It is for servers that can not tolerate any interruption.
Modern hard drives have a advertised mean time to failure on the order of 500,000+ hours. That is something like 50 years. SSD's are similar.
With raid-1 you are protecting yourself from specifically a hard drive failure. Not from other failures such as viruses, operator error,
malware,raid controller failure fire, theft, etc.
For that, you need external backup. If you have external backup, and can tolerate some recovery time, you do not need raid-1
I find it useful to clone my ssd occasionally to a identical ssd as a backup.
If I should ever have a disaster, I can use it to get back quickly without the pain of a new windows install and the supsequent installation of lots of games and apps. Data can be backed up to external devices.

 
RAID setup in a production business environment is a necessity. Zero downtime is a requirement in most installations. When I think of home use, the only benefit that will ever be realized is when you need a very large single volume (i.e. Windows Media Center only allows for a single recording drive for live TV recording). With libraries, you can easily combine multiple volumes into a "single interface".

While RAID definitely has advantages in the business world, the costs make it prohibitive for home use. In the business world, if you have 100 people making $10 per hour, and you lose a server, you are losing $1,000 per hour in productivity (just base payroll). If recovery takes 4 hours, that is $4,000. Paying an extra $2,000 for hard drives in this scenario to ensure zero down time is a no brainer.

But in the home environment, if you had two 4TB drives - one as the main "data" drive, and the second as a backup drive, you can utilize programs like SyncBack (free) to backup the drives nightly, or even synchronize them. 4TB is a lot of storage.....In extreme installs - let's say you use RAID 0 or JBOD to take four 4TB disks to make a 16TB disk - and a second array for backup. If the first fails, the second is online instantly if you used SyncBack.

The downside to RAID 0 - any drive failure in an array = 100% loss of data. Backup is more important....

As for speed, you will see some performance gains, but the pricing of the drives, plus hardware, plus possible loss of data, I wouldn't recommend RAID in the home unless there are no alternatives....
 

landcruiser

Reputable
Aug 8, 2014
2
0
4,510
Wow guys, thanks for all you speedy and helpful info on the RAID systems. Yes, I was drawing this conclusion that RAID is overhyped for useful application in the home invironment, & that the JBOD system may well be an answer with some variant of syncing & backup solution. I've just got a bit of new stuff recently, so been doing some research. I got a Nexstar 4Bay RAID, JBOD Stack, I'll probably use as JBOD now,, and a 4Tb Time Capsule I'll use as extra backup, or maybe it should be the Nexstar RAID1 orJBODplugged into the Time Capsule? Anyhow, thanks again, I got 2 quick replays &. By the time I picked one & sent it, I had 2 more great responses. This is a great forum.