Raid 0, 1, 0+1 differences ?

[mihai11]

Hello,




Can somebody explain to me what are the differences between Raid 0, 1, 0+1, 2, 3, 4, 5, 10 ... or maybe point me to a website where I can read about this subject.



Regards,
Razvan

 

[kumquat]

http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks

 

[mihai11]

http://en.wikipedia.org/wiki/Redund...dependent_disks

Thanks for the link.

I need to use RAID on a client and on a server machine. I intend to use the following:

RAID 0 - server - all I care is data safety
RAID 1 - client - performance

Is this OK ?
Maybe should I say that I had in mind to use 2 Western Digital "WD3200SD 320GB RE" on the server and client. I don't mind to buy an extra drive if more advanced RAID configurations can be achieved this way.



Regards,
Razvan

 

[defakto]

Thanks for the link.

I need to use RAID on a client and on a server machine. I intend to use the following:

RAID 0 - server - all I care is data safety
RAID 1 - client - performance

Is this OK ?
Maybe should I say that I had in mind to use 2 Western Digital "WD3200SD 320GB RE" on the server and client. I don't mind to buy an extra drive if more advanced RAID configurations can be achieved this way.



Regards,
Razvan

I don't think you read and understood that wikipedia link correctly.

RAID 0= NO data safety, NONE, if one drive in a raid 0 array dies you lose everything.

The type of raid you want to chose is very, VERY dependant on what the server is doing. In order to give good advice on what raid level to chose we need to know what you are doing with the server/client. The wrong type of raid for an application can hurt performance more than it can help.

 

[kumquat]

Thanks for the link.

I need to use RAID on a client and on a server machine. I intend to use the following:

RAID 0 - server - all I care is data safety
RAID 1 - client - performance

Is this OK ?
Maybe should I say that I had in mind to use 2 Western Digital "WD3200SD 320GB RE" on the server and client. I don't mind to buy an extra drive if more advanced RAID configurations can be achieved this way.



Regards,
Razvan

Looking at RAID configurations and trying to find a place to put them is not a good idea.

Look at your server, look at your client, and figure out what problems need to be addressed where. If a RAID configuration is the solution, then go for it.

I think that you will find RAID 1 or RAID 10 are great solutions for servers due to redundancy. RAID 0, on the other hand, may look great with performance increases for desktop machines, but the actual performance benefit is almost nonexistant and your data safety goes totally out the window. A better solution for a workstation is one nice fast disk like a Western Digital Raptor coupled with regular backups.

 

[drdeutsch]

here's another linky... maybe this will help:

http://www.raid.com/04_01_10.html

 

[dtess17]

Still having a hard time understanding RAID 5 ....what does it offer?

 

[BillLeeLee]

RAID 5 stripes data and parity information across at least 3 drives. Provides good random read performance, but average random write performance. However, rebuilding won't be as easy as in something like RAID1.

Also requires 3 drives minimum, and can tolerate failure of 1 disk (for tolerance of 2 disks, there is RAID6).

Really intended for things like database servers or file servers, but not recommended for write intensive environments, as compared to RAID1 or RAID1+0.

 

[dtess17]

so it really has no benefit for the gamer or download junkie ?

 

[BillLeeLee]

RAID 5 is really not meant for those purposes, no, because if you do any sort of intensive random writing, RAID5 isn't as fast as other RAID levels.

For desktop RAID something like RAID10 would be suitable. RAID 0 alone is really only good for sequential reading, so it's useful for stuff such as reading large files, but for the most part, normal system use is pretty random in both reading and writing. Plus RAID 0 provides no redundancy.

 

[dtess17]

what are your feelings on 0+1 ? i have heard it isn't the worst.

more than likely i will just run one drive for my OS and one for storage...but i like to keep my options open incase there is a good performace boost somewhere.

 

[unhappy_mage]

so it really has no benefit for the gamer or download junkie ?

Not for gamers, but for downloaders it's a good choice. You only "lose" the capacity of one disk, it's still OOM faster than your internet connection, and it's redundant so you don't have to download all that stuff again if a disk dies.

0+1 is okay, but 10 (which is the same thing the other way around) is better. Stick with one for OS and one for storage.

 

[defakto]

If you're not going to be doing any type of large file editing, such as audio or raw video, and you aren't pumping data out over gigbit networks at max speed, for the home user there really isn't any that great of a performance advantage for raid to justify it. If you're looking for overall performance it would probably be cheaper and more reliable to go for a single, fast, new drive than an array. Unless you're going for ePenis factor.

 

[dtess17]

hmmm, i guess there isn't much point for RAID in my case then.

i will just get 2 16mb cache drives then....yay!