Questions About Raid-5

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PAo_ReVoLT

[H]ard|Gawd
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Apr 4, 2008
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Hi Everybody

I'm planing to make a data server for my AV collection now i used 2.5 TB but it is expanding about 300GB/mo (currently i'm using 3x 1TB drive on my gaming pc) i'm going to make another server and get a raid card so the question is

1) when i make raid-5 lets say i used 4x1TB so i will get 3TB partition right? now if i want to add another drive to make it larger do i have to reformat everything or i can just popping in another drive and the raidcard will remapping all data?
2) do i need a powerful processor (i have 3.0ghz prescott) in order to make a good raid-5 or it is just about the card

thank you
 
hardware RAID doesnt care about the CPU, its doing the calculations itself. Software RAID does care, but if you arent doing anything else on the computer thats more than enough CPU.

Depending on the card you can get online capacity expansion, which is what you were asking about. Modern OS can expand a drive, or add a new letter/mount for the new space.

Example being my 2320, which has been expanded from 4x300 to 5x300, and the array wasnt down at any time except for the new drive install itself. Thats the ability youd like. You do however, have to wipe during the initial setup for the array. I dont think you can go from a single to a R5 array with most cards.
 
If you run windows, a raid card will be most stable. If you run linux its a toss up. You can get better performance with software RAID under linux than a lot of hardware solutions (especially in a non-enterprise level). You do have to worry about data corruption during power failures with software RAID.

If you have 3 or 4 1tb disks in a RAID 5 you can easily add another in a few months. At some point you may want to move from RAID 5 to RAID 6 or you may want to start another array when you start getting 1.5 or 2tb drives.


Honestly, you might do best with unraid from http://lime-technology.com/

You can download the software and burn it to a USB stick. It boots from USB leaving all of your SATA controllers free for drives. Tt will let you use odd sized drives and provides data redundancy and lets you spin down drives when not in use.
 
i have take a look lime-tech site it look very good IMO but i dunno what i want is match with the software

here i what i want to do

- i want to have large single drive (3 TB for now) show in the window/network
- it has to be expandable without formating the old drive (coz if i has to format it i dont have spare space for 3tb data)
- at least 1 step protection (i mean if 1 drive broken i can rebuild it without data lost)

please give me some advice

thank you
 
PAo_ReVoLT said:
- it has to be expandable without formating the old drive (coz if i has to format it i dont have spare space for 3tb data)
Click to expand...

The 1st and 3rd requests have already been answered: Definitely RAID5. The 2nd request has already been answered: You're looking for a feature called Online Capacity Expansion on the RAID card. It will allow you to expand (add another drive to) your current RAID array without losing the data.

However when you do the initial RAID setup, you will have to reformat the drives and as result will lose any data on those drives. So you cannot take your current 3x1TB drives, add a 4th drive and setup a RAID5 array without losing all data currently on those 3x1TB drives. You will have to find someplace to store those files while the RAID5 is being initially setup. After the RAID5 has been setup, you can add as many drives as you wish without losing the data.

There are two different kinds of RAID cards out there:
- Hardware RAID
- Hardware Assisted Software RAID

A true hardware RAID card has an onboard CPU that takes care of all of the parity calculations neccessary for the RAID array. As a result, you'll see little or no CPU usage whatsoever in your main system and fantastic speeds. But the big con is that hardware RAID cards tend to be significantly more expensive. (We're talking $300 for just a 4 Port card)

A hardware assisted software RAID card just handles the setup of the RAID itself and has the PC's CPU handles the parity calculations. As a result, you'll see high CPU usage, especially on a single core CPU, and lower speeds. But the big pro is that hardware assisted RAID cards tend to be significantly cheaper. (We're talking $150 for a 4 port card)

Now what's your budget for your new server? Are you planning on reusing any parts for the server? If so, what parts are those?
 
thank you for answering it is very clear ^^

now i have about $1500 budget i have gigabyte x48 motherboard the prescott 3.0 ghz have 2x2 gb ddr 2ram and ati x1900 so 1500 will go to

case
raid card
2more 1tb hdd
1 cheap lcd monitor
router & networking stuff

so do you think i be able to get the Hardware RAID (i think i need 8 port one)

thank you again

(u guys are so helpful ^^)
 
With that budget, you can definitely get a new 8 Port Hardware RAID card:
Areca ARC-1220 PCI-E x8 8 Port SATA II Controller Card (Hardware RAID) - $435

Why do you need a cheap LCD monitor?

Router wise, I recommend this router:
D-Link DIR-665 Xtreme N Gigabit Wireless Router - $93

Been using it myself and haven't had a single problem with it so far (have had it for almost a year now)

What 1TB drives are you using right now?

Case-wise, anything specific that you're looking for? And is a new PSU included in that $1500 budget? If not, what PSU do you plan on using for the server?
 
i need a monitor coz currently i dont have a spare monitor so if i build a new server i want to use something from it

back to the topic

i'm looking at 16 or 24 port sata2

http://www.newegg.com/Product/Produ...k=&SpeTabStoreType=0&Order=PRICED&srchInDesc=

i know it is expensive but it look good tho since i can add more drive later

now i'm using seagate 1tb ES.2 in my country i can import it for around 210 usd so i think i need 2 new one and create raid-5 so i will get 1TB then move the files from my old drive and add it online and so on

so 2drive + card run around 1200usd

then i need the case that hold 24 drive (internal) probably 1 case now and 2nd case later

then a psu that would support 12 drive first

so do you think 1500 should be enough or i should raise my budget to 2000 ><

thank you
 
You should be able to find cheaper cards on eBay, and despite my hatred for that site, it does have some surprisingly low-priced RAID cards (I got my Adaptec 31605 for $450 when all was said and done, it's a 16-port hardware RAID card that MSRPs for $995).
 
Man I was about to go into a long diatribe about your server but then I remembered that you're getting about 300GB a month of new data. So I guess your expenses is justified. If you sustain your current expansion rate of 300GB a month, that's roughly 3.6TB per year. With the recommended below RAID card and a 15TB RAID5 Array, you should have plenty of space for roughly 4 years:
Areca ARC-1260 PCI-E x8 16 Port SATA II Controller Card (Hardware RAID) - $790

Do you happen to have this Rackmount case available to you in any way?:
NORCO RPC-4020 4U Rackmount Server Case - $290

It can hold up to 20 drives. So should be plenty of room for your 16 drive 15TB RAID 5 Array as well as a single system drive.

But check eBay (if it's available to you), like Syntax Error recommended, to see if you can find any cheaper RAID cards.

You're gonna have to up your budget.
 
most ebayer they don't ship outside the states if they will they will have either ridiculous price or very complicate billing system (like i have to wire money to them first stuff like that)

but i think i will do like you to me so

i will get that kind of raid card and will fine 4U rack (may be 2nd hand if i can find 1)

thank you for you guys

your very helpful

BTW i'm from bangkok, thailand
 
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