Raid 1 verses 0+1

[hipster]

OK, I just read a little primer and it seems Raid 1 is the safe bet since I would "store" pictures and video stuff on Hdd, and Raid 0+1 would be even better (pick up extra speed) but you have got to have 4 Hdd's which I don't have. That sums it up right?
Would/should I still setup XPpro on seperate ide hdd or just use 2 hdd with Raid O+1?
Lastly, it seems that if money was not a concern, it would make sense to also use 2-SATA-Raid O just to do encoding correct?
Thanks for your opinions! Bill

[CCW]

RAID 0+1 basically, you create a striped array then mirror it so the stripe now has redundancy as normally, RAID 0 is the only level of RAID that provides no redundancy. You need a minimum of 4 Hard-Disk Drives for RAID 0+1 and need to add extra drives in pairs if you plan to add more drives. The twqo SATA RAID 0 would be fast but no redundancy is provided so if one drive fails, you lose all of the data.

Craig

[FireMogle]

Also if you plan on adding in 4 drives into an array, you may want to start thinking about higher RAID levels. 0+1 gives you half of the storage you put into it while RAIDs 3 and 5 give you back a higher percentage by mirroring the data differently. It will cost more to put in but you will get more back from it as well, just another option if you need it to be.

[CCW]

Except RAID3 is rarely used nowadays. RAID5 is a much better solution. RAID 5 needs at least 3 disks and always an odd number of disk. You have two drives holding data and the third holds parity. Parity is information about the data but not the actual data itself so it has enough information aboutg the data to re-create it if its is lost.

RAID5 provides a good level of redundancy and speed.

Craig

[wquiles]

The other alternative to RAID5 or RAID 0+1 is to use a cheaper/slower hard drive to do a nightly backup of the RAID 0 array - this is what I do in my own system. So with only 3 drives you could have very high performance (two fast drives in RAID 0) and a very good backup solution (slower drive). With the proper backup software you will only backup those files that change, so the night backup is always quick :-)

William

[CCW]

wquiles, thats not a bad idea however the idea of RAID is that it saves time, it makes redundancy much easier and less time-consuming. Id hate to do a full backup everynight, an decremential or incremential I wouldnt mind but a full backup everynight is time consuming.

Craig

[ajrettke]

99.9% of people here will find RAID 5 useless. The only reason for using RAID 5 is if you have massive amounts of data that you CANNOT lose. I.e. over 400gb or so. The reason, RAID 5 is incredibly SLOW. If you haven't used it, please don't suggest it. Only in the high end SCSI realm does RAID 5 start to look apealing. If you want speed, do this:
run 2 seperate RAID 0 arrays and have winXP backup all data every night. RAID 0+1 is still not very fast. In writes it's the same as a single disk, and reads only marginaly faster.

All my findings are based off of a 4 channel IDE controllers with 4 80gb 8mb ATA133 drives.

Also, ask yourself what's more important, speed, or safety? If it's safety then just run a plain ol RAID 1, if you want speed run RAID 0's and backup the array to aother disk...i.e 2 120gb in raid 0 and back them up at night to a 250gb drive.

[wquiles]

Craig - 100% agree with you. I full backup every night would be very inefficient, specially in my home setup. I can't afford to have RAID 1 in all PC's, but backing up to an extra hard drive works for me.

I have a couple of PC's in my home network and all of them do a nightly backup to a "server" PC using a program called Second Copy 2000. The PC's automatically do an incremental nightly backup, which is always very quick given that so few files change daily :-)

William

[CCW]

Ah excellent! The incremental will certainly save time than doing a full daily backup.

ajrettke, you say not to suggest it unless I've used it...I have used RAID 5.

Craig