RAID???!!!?!?!?!

[Guest]

While i was looking for a new mobo for a t-bird around 1000mhz,i noticed mobos supporting RAID.I think it synchronize 2hd together but im not sure.....so can someone be kind enough to explain to me what are the benefit of RAID....Or maybe they installed the famous RAID bug spray on mobo to kill bugs in there....just a wild guess.

 

[Guest]

If you're serious about RAID then buy a proper RAID controller. To be honest it really isn't worth the effort and especially the cost!

I've got three 9.1Gb UW SCSI hard drives and a RAID controller sitting in my cupboard generally not doing very much apart from chatting quietly to eachother in the dark.

Cabling is a nightmare from hell, imcompatibilities around many a corner and the things get so hot the entire RAID system grinds to a halt.

Spend your extra pennies on that 21" monitor you've always wanted because RAID can be a little disappointing if you just try to throw it together.

I'll get the drives out again one day and have them running properly in RAID 0 at some point. You have to really build your system around RAID since the drives have to be all together sitting in your case with cable lengths and restrictions to think about.

If you're going to try RAID anyway do some research first, there's loads of info on the net about it.

 

[Guest]

I have an Abit KT7 raid motherboard running two IBM Deskstar 15Gb drives in a raid O setup. Note this is IDE raid not SCSI raid. I found the raid controller easy to setup and the drive performance is outstanding with HDTach giving a sustained throughput of 65Mb/s although CPU useage is a little high at 24% during the test. A little research and some bios tweaking should get the CPU useage down considerably.

With raid O (striping) the data being written to the drives is divided equally between them thus virtually doubling drive speed. The same occurs during drive reads with half the data coming from each drive.

If you are considering getting a motherboard with an on-board IDE raid controller take the time to do some research beforehand regarding setup and you will be rewarded with a much faster system for only a little extra cost.

Aussie

 

[uncoando]

redundant array of inexpensive drives. As Aussie points out, raid is no longer strictly scsi. Whereas configuration used to be a bit tricky, now it's a p and p type operation. Also, the cost of onboard raid controllers is so attractive you almost cannot pass the option up. There are many flavors of raid, stripping gives you speed advantages, mirroring and duplexing give you data redundancy.
I run an Abit BX-133 raid w/ 2 20gb ibm deskstar ata/100
hds.
<b><font color=blue>Brainy Sturgeon</b></font color=blue>

 

[Guest]

I, like Aussie, have the Abit KT7-raid mobo, with 2-15gb IBM Deskstar ide drives. I also, have found that the throughput of the drives running in parallel is about 65mb's. Not only does raid do striping, but it also does mirroring, with no slowdown of throughput. The setup is simply done through the bios and, with my striped drives on the raid controller acting as my boot drive(c, it leaves my two ide connectors open to attach four ide drives(cdrom, cdrw, zip, etc.). That makes a total of 8 drives on the mobo without any problems. Abit is also great at updating drivers and bios. I have had only two lockups in two months with this setup. So, for about twenty dollars more for the mobo, and the cost of a second drive, raid is the way to go.

 

[TazMo]

The several different types of RAID, but from the standpoint of simplicity most of the new wave RAID is built into the MOBO. The performance gain is with something called RAID(0) or striping. You need two harddrives generally the rule is same type size etc. The hardware controller sets up the RAID array, once its set you must partion and format. The computer sees the two harddrives as one big drive.
How it works would be to think about writing the 26 letters of the alphabet. If you wrote with only one hand you could only write them down so fast.
If your brain were a RAID controller and you were ambidextrous each hand could write every other letter. Each hand would only have to write 13 letters if it's done at the same time it would be faster.
Real example The RAID controller sets a stripe size of 64kb. If the info you're storing to harddisc is 128kb then the controller will send half the data to one disc the other half to the other. It does this roughly at the same time. So it's faster. In fact it's alot faster.

I went with the RAID setup because it was a good bang for the buck. The on-board RAID was about $20 more than the same MOBO without RAID and two 15GB IBMs were about $60 more than a single 30GB. So for about $80USA more I got a RAID setup. If it was more than a couple of hundred dollars I wouldn't have bought.

 

[TazMo]

Aussie your HD tach scores looked like mine.

When I first put together my system with ABIT KT7R and 2-15GB IBMs I used the default RAID setup stripe size of 64kb. I installed my system and then ran some benchmarks HD-tach etc.. I then ran across some web sites that told me the ideal stripe size is 16kb so I reset the RAID and reformatted etc. Re-ran the benchmarks and and noticed that my all my performance marks were up about 10% but my seek times had increased by.5ms from 9.3 up to 9.8 and my CPU usage was at 29% up from 13%. Anyhow I went back to the default stripe size of 64kb. Life is good.

Thought you might like to know.

 

[Guest]

Well, raid 0 can be used with a single drive. you will see a HD speed increase of about 50% with a raid hardware solution. Raid is not hard to setup at all. WinNT4.0 and Win2000 offer a softerware raid 0 solution (striping). If you use a software solution you will see about 20% HD speed increase. You only need one drive for this as well. The software solution uses more CPU power. The hardware solution uses the risc processor on the raid card and on some cards you can add ram. I think Adaptec is by far the best.

 

[Guest]

Hi all. This thread is interesting as I have been exploring an inexpensive raid solution. I'm new to Raid in general. I like the idea of the performance increase you mentioned with Raid 0, but what happens in the event of a drive crash? Can you do both (raid 0/1) at the same time and how do you implement this with the onboard IDE Raid controllers offered by Abit and the like? Thanks!

 

[TazMo]

The onboard IDE RAIDS support both modes, but to do both you'll need four drives. The two primary drives will be striped and the two secondary drives will be mirrors of the striped drives. This set-up gives you both safety and performance, the only thing is that the two extra drives are stictly for backup. So they can't be used for normal storage. SCSI RAID setups can also do something called striped plus parity, where it uses three drives and if one disk fails it can be restored with info from the other two, but the onboard IDE RAIDS don't support that mode.

 

[Guest]

Sorry Dataman, I think you are incorrect. If you are saying that you will notice a speed increase of about 50% using a SINGLE drive then I certainly believe you are wrong. RAID will only work with multiple drives. If you want a defenition, RAID is an Redundant Array of Independent (or Inexpensive) Disksthat employ TWO OR MORE drives in combination for fault tolerance and performance.
I can't even see how it would be possible to boost the performance of a single drive by 50% since it is already going as fast as it can (assuming its not being bottlenecked by an older ATA controller). Its like saying that my cable has a capped upload of 15KB/sec, but if I upload two things silmultaneously they will both be going at 15KB/sec. In addition, the performance boost you would get with data striping (Level 0 RAID)would realize about a 200% sustained throughput over a single drive (assuming both drives are identical), or possibly a little less depending on the quality of the controller you are using.

THanks

 

[Guest]

Thanks - I was wondering. And again, being totally new to Raid, here's another for you: Can you take an OS that doesn't itself support raid, and make it work with a hardware raid solution? For example, I want to use Win2kpro which doesn't support mirroring, and use raid 0+1 so I don't have to worry about hard drive crashes, but don't want to spend the money on the Server ver of Win2k. As I migrate systems to Win2kpro from Win98, I find the most annoying thing about NT-type systems is the inability to make an unattended mirror copy onto a redundant drive in the middle of the night. My backup solution for my 9x systems was always to purchase a second hard drive, "mirror" (i use the term loosely) my main drive to it using xcopy32, then each successive night after that use a utility called inSync to keep the mirror current. This was always convenient because if the main drive crashed I simply made the mirror the new master, then fired up fdisk and made it active, and voila, I was back without the hassle of restoring from tape or any of the other hassles associated with real honest to god backup software. If the mirror dies, I just get a new one and redo the mirror, nuff said. Anyway, I digress. Is it possible to use hardware raid on an OS that has no software raid support? Thanks again, and please to excuse extreme newbieness!

 

[TazMo]

Since it's hardware, your main concern would be if there is driver support for the OS. The operating system doesn't matter. The ABIT KT-7R does come with drivers for Win2000. Hardware RAID is transparent to the OS. All setup and modifications are done in the startup BIOS.