RAID 0 or RAID 5?

mystery42

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I was wondering what would give me better performance a RAID 0 or RAID 5. I know that RAID 5 wouldn't give me more performance but would it yield the same performance as a RAID 0 with two 1TB drives? From what i understand RAID 5 is just as good but offers redundancy or am i mistaken? I was hoping i could do a RAID 5 with 3 1TB drives since a while back i lost one of my 250GB drives and ended up loseing alot of important information, come to find out the drive was fine it was the motherboard but had i done a RAID 5 i could of just rebuilt the drive.
 
Solution
raid 0 has NO redundancy - if either drive goes, you lose your array. RAID 5 gives you redundancy by spreading parity data across the different drives (although there are some issues with very large disks in raid 5 arrays, in that the more data you have, the greater the odds of a soft error hurting the possibility of recovery).

RAID 0 gives you better performance than raid 5.

Neither solution replaces the need for a good backup. THAT should be your data security. Why does raid 5 exist? Some people/businesses need high uptime, and can't afford to be down while they restore from backup.

gtvr

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raid 0 has NO redundancy - if either drive goes, you lose your array. RAID 5 gives you redundancy by spreading parity data across the different drives (although there are some issues with very large disks in raid 5 arrays, in that the more data you have, the greater the odds of a soft error hurting the possibility of recovery).

RAID 0 gives you better performance than raid 5.

Neither solution replaces the need for a good backup. THAT should be your data security. Why does raid 5 exist? Some people/businesses need high uptime, and can't afford to be down while they restore from backup.
 
Solution


On the desktop you won't be able to notice the difference other than boot times of if your using specialized applications (movie editing, large databases, etc.

If you have 1 PC, redundancy is easily provided by an external drive.

If you have several, provide redundancy for multiple systems with an NAS>


 

mystery42

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I decided to just do 2 RAID 0. I'm getting a 5900RPM 2TB drive as a backup and i'm also considering putting an external USB 2.0 2TB external hardrive on the network for backing up the entire house. My new router will come with a USB 2.0 hookup in the back. That way i get an external backup but i don't have to spend the money for the NAS. The other 2 computers are only a 250GB desktop and an 80GB laptop

New Computer hard drive configuration.
2x250GB - Random Stuff - RAID 0
2x1TB - Operating System/Programs - RAID 0
1x2TB - Backup
 

gtvr

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The last thing I would add, if you want to be really paranoid...

If you have truly irreplaceable stuff (kids pictures, financial documents, etc) - once in a while, burn them to a CD or DVD, and take them out of your house. Or back them up on the net somewhere.
 

rodmanlab

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Some quick comments on your config:

2x250GB - Random Stuff - RAID 0 (Not much space, recommend you switch to OS)
2x1TB - Operating System/Programs - RAID 0 (This should be your files drive, so you can match the size of the backup with this array)
1x2TB - Backup

You might want to consider a separate drive/partition for virtual memory and scratch disk.
 

chedderslam1976

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Raid 0 is nice until a drive dies. Not a big deal when you can just install an os and programs. Just lost time.

But your media drive? What about those photos or music that you haven't had a chance to back up yet?

It's really nice when I want to do a clean install of windows. I just install, point to my libraries on the raid 5 array, and install my software. My DATA is always secure.
 

mystery42

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Would it be a good idea to put the pagefile on the backup drive. As it will most likly only be used once a week i figure putting the pagefile on it would atleast give it more of a purpose plus i heard that by giveing the pagefile its own drive it improves performance.
 

mystery42

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I like the idea but what is a scratch disk i've never heard that saying befor. Also last time i tryed to partition a RAID configuration the RAID on the motherboard failed. I don't know if thats normal but thats what happend. Its the main cause as to why i'm looking for backup storage i tend to jump the gun and format the drives befor i test to make sure there really dead. In retrospect i now relize how dumb it was to format the drive since if the drive was dead formatting it would not be possible.
 
^About the swapfile: For most users/programs you do not need a swapfile anymore with at/above 4GB or RAM. Also, do realize that if you leave the swapfile a lone, it's essentially wasting about 6GB or so on the SSD, given the fact that swapfile isn't that needed I'd reduce the size or disable it. I've been running with out a swapfile,even on my CAD machines and it works fine.
 

rodmanlab

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Windows was designed so that it would always use the "swap file" a.k.a. "virtual memory", not sure why, but I asked once and Microsoft indicated that even though it can operate well, the swap file acts as a redundancy method for storing information. I have a workstation with 20GB DD3 RAM, disabled the virtual memory and Windows 7 Pro gave me a warning within a few minutes ... so rather be on the safe side ... partition for a couple of Gigs, make it on a separate drive (not where the OS resides) and allow the OS to manage it ... so you won't worry about it anymore.

Now, "Scratch Disks" is a term used by Adobe to reference disk space used for temporary files. Since we are talking about DCC (Digital Content Creation), this usually requires several Gigs, even more if we are talking about video editing. Scratch disks really hurt fragmentation if you are using your main drive, so again, partition another one and give all these programs a single location to do their thing ...

A side note regarding benefits of partitioning for virtual memory and scratch disks, these sectors will be constantly written/erased, so fragmentation will be considerable in a main drive, if you keep it on a separate one then is much easier to keep a healthy, high performance OS drive without requiring so many defrags ... Also will diminish time for antivirus scans (full scans that is).

Hope this helps, ;)
 
G

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Agreed with aboved.
I personally use high rpm, low latency 2 drive raid 0 for ONLY windows page file and all other temp (setting windows temp folders, browser temp folders, download temp folders, etc) Os drive is strictly os and program files only. since only read is performed raid 1 wins. more drives in raid 1 = faster read.
You can add drives to the raid 0 for added performance, thats why i only use small drives. 2x 36gb u320 scsi 15k cheetahs. you can always go the consumer route and do wd velociraptors or even 3+ older raptors should get you the same perfomance.

As far as degredation goes, really depends on the controllers/software.
If you have good hardware, then all thats left to fix is the software. lol.
Most decent controllers will have functionality to maintains your arrays but some require user intervention (software based chips whether you have an amd or intel board with intel, lsi {nvidia}, jmicron {gigabyte likes to use these})

I've noticed some users on this and other forums complain of slow raid 5. thats not the hardware but the user who did not set it up properly. Even onboard fake raid (software) has the capability of 100mb + through-output.
Helps to match stripe size with drive format sector size. <-big hint. less cpu calc required to break down data to match stripe size . (durdur)
Please install the software from intel (intel matrix storage manager) nvidia (nvidia chipset drivers), or what ever board you have. Softraid requires software to maintains performance. dont skimp on it because your nlite'd xpsp3 auto installed drivers and it "works"
Windows wdm drivers are also a joke and waste cpu.