• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

Defrag Raid 0?

M

MunchMouth

Weaksauce
Joined
Dec 2, 2008
Messages
65
I have 2 500gig Samsung HDD's in raid 0. I did the PC pitstop test and it said I need to defrag my C/ drive. I read somewhere that it is risky to run defrag on raid arrays, am I right or wrong? Also which defrag prog. works best? I have Vista Home prem. 64bit.


thanks, Munch
 
MunchMouth said:
I have 2 500gig Samsung HDD's in raid 0. I did the PC pitstop test and it said I need to defrag my C/ drive. I read somewhere that it is risky to run defrag on raid arrays, am I right or wrong? Also which defrag prog. works best? I have Vista Home prem. 64bit.


thanks, Munch
Click to expand...

Vista Defrags in the background without your knowing.
Yes its ok even though its a raid array.
 
I have heard that it is unwise / inefficient to defrag any sort of raid array, however i think in practice, this is not correct. I'd wager that this was a problem on earlier raid controllers and tech, but nowadays, you would be hard pressed to find someone advocating that you never defrag your raid array, no matter the sort (R0-->R5, etc).
 
Considering with possible fragmentation, and assuming worst-case scenario of 1MB block size on a raid array, it's very possible to have to read 1MB at a time on a drive just to get one 4KB cluster.

That's very inefficient.

I know I get bad fragmentation on my arrays, and I have raid5 with 32KB blocks sizes with 4KB clusters, and it absolutely kills performance.

I certainly defrag.
 
its safe to defrag raid arrays and does improve performance. its only SSD's that you want to avoid defragging... or raid arrays using SSDs.
 
Defragging a RAID is just the same as defragging a single physical disk, because all said and done, Windows sees the array as a single logical disk; the distinction between the elements of the array is at the point of the RAID controller.

I don't run RAID, but some of my friends do for their XP rigs, and most use Diskeeper 2009 Pro, or the older 2008 Pro to defrag. Supposed to work fine. I use DK09 on my non-RAID systems, and I can attest that it's great on those.
 
Magnetoman is correct. Files on a disk are oriented into 512 byte sectors, and it's these sectors that make up a particular file and they are not always contiguous, which a defrag will correct. If all your files saved to disk were smaller than the stripe size, they would all reside on one disk regardless of how many drives make up the RAID system thus suffering from the same fragmentation of a single disk system.
 
maven said:
Magnetoman is correct. Files on a disk are oriented into 512 byte sectors, and it's these sectors that make up a particular file and they are not always contiguous, which a defrag will correct. If all your files saved to disk were smaller than the stripe size, they would all reside on one disk regardless of how many drives make up the RAID system thus suffering from the same fragmentation of a single disk system.
Click to expand...

This is ignoring the cluster size, though. A file system sees a storage device as clusters, not sectors. Saying that files smaller than the block size means they reside on the same disk is more than likely not exactly accurate.

If you are using 32KB cluster sizes in the OS's file system, and you have a 1-byte file, and are using 32KB block sizes on the array, that 1-byte file is not just taking up that 512-byte sector, it is taking up that 32KB cluster, thus is it (assuming the clusters and block start/end at the same spot) taking up that entire block. So in this example only that single 1-byte file resides on that first disk.

Making the block and cluster sizes the same can help keep performance from plummeting on a raid array that is/gets heavily fragmented. If you save small files though, it can end up in "slack" though.

But my main point is is that a raid array (compared to a single disk) will have more severe performance drops if you do NOT defrag. The block sizes of the array are generally bigger than the cluster sizes, meaning more of the disk must be read to get to your data.

If you need to read a 1-byte file, and you have 1MB block sizes on your array, the raid controller will read the entire 1MB off of your disk to get that 1 single byte. For massive amounts of random reads/writes, on something with high fragmentation, it absolutely kills performance.
 
YES you need to defrag your RAID0 array. It's safe and it needs to be done.
 
Thanks for the replies! I guess I will try vista's defrag. I liked XPs better I could see the progress!!
 
Diskeeper makes a pretty darn good product. Worth the purchase and better than Vista's built in defragger. Yes there are other defraggers out there, even free one's but that is another story....
 
Both my OS and Data drives are in RAID 1, I know you said RAID 0, and I let Vista do the defragging. No issues thus far.
 
Brahmzy said:
Diskeeper makes a pretty darn good product. Worth the purchase and better than Vista's built in defragger. Yes there are other defraggers out there, even free one's but that is another story....
Click to expand...


They do make a good product. I was quite dissappointed to see that they fired employees who didn't want to join the Scientology religion. Unfortunately the other choice, PerfectDisk, chose to release a product that they said speeds up your SSD's and really doesn't do jack shit, which is the equivelent of fraud. So pick your poison. They work, but whoever you support, you still end up giving money to a jack ass.
 
hasoos said:
They do make a good product. I was quite dissappointed to see that they fired employees who didn't want to join the Scientology religion.
Click to expand...

Wow. I had to google that up. That is lame.

How does O&O rate these days?
 
hasoos said:
They do make a good product. I was quite dissappointed to see that they fired employees who didn't want to join the Scientology religion. Unfortunately the other choice, PerfectDisk, chose to release a product that they said speeds up your SSD's and really doesn't do jack shit, which is the equivelent of fraud. So pick your poison. They work, but whoever you support, you still end up giving money to a jack ass.
Click to expand...

Yeh, no joke! My Diskeeper rep was let go. This was an awesome guy who got me mad amounts of discounts. I've got over 1,500 copies of Pro and Server mixes at work + maintenance and he always gave me HUGE discounts on it when I purchased and renewed maintenance. This pisses me off.
 
You must log in or register to reply here.
Back
Top