To RAID or not to RAID.........

hail-hail

hail-hail

hail-hail

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I have a new media PC with 1.5TB SATA HDD running Vista Home Premium.

I have just purchased 3 1TB SATA HHDs.

So should I RAID them?

I already have Vista on the 1.5TB HDD

RAID0 - distributes the data over all 4 disks, any one disk failure and everything is lost.
Can I setup RAID0 without having to reformat and reinstall Vista?

Should I even setup RAID0 I am only ripping DVDs, Home movies and Pictures to this PC. Pics and Home movies will be backed up to disc.

Do I really need RAID, or should I just use as 4 independent HDDs.

Apologies if some of this is a bit fuzzy, but I am new to this :D

alan
 
RAID 0 does greatly improve speed I've found.. but if you're worried about data loss, maybe it would be sensible to purchase a 4th 1tb drive, then set up RAID 0+1 with them. That way you get both speed + safety.
 
hail-hail said:
RAID0 - distributes the data over all 4 disks, any one disk failure and everything is lost.
Click to expand...
You would also lose the extra 500Gb on the 1.5Tb disk

hail-hail said:
Can I setup RAID0 without having to reformat and reinstall Vista?
Click to expand...
If you want to include the existing boot drive in the array then you will lose all the data on it and a reinstall will be required.

hail-hail said:
Should I even setup RAID0 I am only ripping DVDs, Home movies and Pictures to this PC. Pics and Home movies will be backed up to disc.

Do I really need RAID, or should I just use as 4 independent HDDs.
Click to expand...
For a media PC I wouldn't bother with RAID0, there's no need for the extra performance.
 
RAID1 will give you the 2x the read speed, same as RAID0, but only 1x the space and (assuming 2 disks here) 1x the write speed. Unless your operations are very write intensive (highly unlikely), for general use RAID1 will give you the best of both worlds.

No, you cannot upgrade from a single drive to RAID0.

If you need multiple drives and you want redundancy, you could try RAID5, Intel's SB ICH9R/ICH10R can do RAID5.

Best block sizes (RAID0/RAID5) are reported to be around 8-16KB. This is counter-intuitive to some of us old-school people who tend to go with 64KB based that this is the maximum block size that the DMA controller can handle in one transfer. However, in typical use this can be sub-optimal for accessing lots of small files. Most disks support transferring up to 16 sectors in a single operation (typical sector is 512 bytes, which gives a figure of 8KB), so 8KB is a good ball park for what to set the block size to for minimizing overheads.

Safety issues:
RAID0 increases failure probability exponentially. 2 drives are 4x more likely to cause a failure than 1 drive.

RAID5 becomes statistically ineffective with more than 6 1TB drives. Consider that modern disks have an expected uncorrectable read failure rate of 1 bit in 10^-14 That's one uncorrectable error for around 12TB. So if you have a 7x 1TB RAID5 array, and you suffer a disk failure, you will try to rebuild onto a fresh disk. To do that, you will have to read the other 6 1TB disks completely to reconstruct the redundancy onto the last disk. Since read error rate is 1 every 12TB, and you are reading 6TB, you have a 50/50 chance of encountering an uncorrectable error while reconstructing, and thus being unable to reconstruct the data. 50/50 chance of data loss is a tad too high for most people. The fundamental problem is that error and failure rates have stayed the same while the disk sizes have skyrocketed. Account for this in your plans.

Also consider probability of multiple drive failure. In RAID5 this is impractical, but in RAID1, use different disks (different manufacturers) of same size. The probability of having two disks from the same batch fail very close together is rather high. On the other hand, this is highly unlikely if disks are totally different (environmental issues such as a duff PSU notwithstanding).

Be safe.
 
Thaks guys, some great info there. I have decided that for the time being I will not use raid.
I have 1x1.5 and 3x1TB disk all configured as individual disks. Movies run from the Hard Drive with no issue, even Blu Ray and HDDVD rips.

I will split my movies by genre over different HDDs. That way if one goes, then I have only lost a subset of my films and then it is just the pain of re ripping them.

Photos and home vidoes will be copied over 2 HDDs to give me a more secure feeling around these. I may also burn offline copies to Blu-Ray.

thanks again for all your input :D
 
You could have used software mirroring to mirror partitions rather than drives.
that means you could have 500GB OS partition + 2x 1TB data partitions mirrored.

In theory that works but i've never actually tried it.
 
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