About to set up a software RAID5 unit

[Damodred]

It will most likely be 8x160gig Maxtor IDE disks on a computer that is not clocked. CPU is an AMD Barton 2500+ with 512mb 2700PC Ram. What readingspeeds am I most likely to get (more or less)? OS will not be on this partition, am I likely to be able to stream say mp3 and movies (Xvid, SVCD, younameit) from it without stuttering?

How much cpu-power does a software raid5 take? Will I be able to do, say play a computergame if the game is installed on a different hd? Does RAID5 take cpu power even if no one is activily using it (reading, streaming mor just browsing)


Reason I ask all these annoying questions is that Im gonna use it for homeuse only and I dont feel for paying 400$ for a raid-controllercard :) Oh and would I get a higher overall speed if I added another 256mb of ram?

Thanks in advance for all answers
regards
Damo

Oh and this also leads to another question :)
Say I do make a rai5 and it works better than anything on this planet. What will happen if I upgrade to XP pro? Its my favourite OS actually. Will it ruin my nice raid5?

Again, thanks in advance :)

[BipolarBill]

The issue iss not CPU power - it's PCI bandwidth. PCI maxes out at 133MBs and your RAID array will be using 70-100 all by itself. Other PCI devices (cards) will cause bottlenecking.

You need a RAID 5 card. Promise and Highpoint both make affordable SATA RAID cards. The only 8-port RAID 5 PATA crads I know of are made by 3Ware, are very expensive and require a 66MHz PCI slot. Promise makes one SATA card that can support 6 drives:

http://www.promise.com/product/product_detail_eng.asp?productId=86&familyId=2

In other words, you will either need a server/workstation motherboard with PCI-X slots for one of the 3Ware 7506 cards or you will need multiple cards for your PC.

[Damodred]

I see, but will this huge bandwith be used even when Im not actually activly using the the disks?

[BipolarBill]

How often are you not using the disks? Besides, you need the disks for just about everything.

[Damodred]

Hehe, now I cant resist setting this up anyway :) So yesterday I tried but...it wouldnt work. Im trying to set it up like 6x160gig, where four disks are on a PCI controllercard and where 2 are on the mainboard controllercard (PM/PS).

Now I know that I shouldnt mix different brands of hdds but I have anyway...I got 4 Samsung Spinpoints with 8mb cache and 2 Maxtors DiamonPlus9 with 8mb cache. There are two Samsungdisks and the two Maxtor disks on the controllercard which leaves me with 2 Samsung on the motherboard together with an 80gig bootdisk and a dvd-burner.

Here comes the weird part, I cant use the maxtor disks in the raid-array. It just wont let me. First I tried to have all disks as logical disks which didnt work cause somehow I couldnt make the maxtor disks logical. Second I formated everything so I had 6x160gig as unallocated space (think it said that, using non-english O/S), I rightclicked on one of the disks and chosed to make a raid-5 array. Now I could only add the four samsung disks to the raid.

Last I tried to make the Maxtordisks as logical partitions and have the other four as unallocated, now it turned out that one of the maxtordisks were unable to turn into a logical unit so if I should do somehting I had to make it into a single unit. The other maxtordisk went fine, altho even if I made it into a logical drive I couldnt make it into a raid5 together with the four Samsung- disks.

Any suggestion on what to do here? I feel kinda lost actually. All disks are using Master/slave commands instead of Cable Select, but I dont think that should affect anything. Regarding to what I read on microsofts homepage it said I should be able to do mix SCSI with IDE and EIDE if I wanted to, plus it would take the shape of the smallest size of the harddrives. The Samsung disks are 1200mb smaller than the Maxtor disks, altho I tried to make logical units with the exact size of the Samsungdisks from the maxtordisks, still it wouldnt work.

Any help is most appreciated :)
Regards
Damo


*edit*

after fiddling around a bit more it seems like I cant turn any of the Maxtor disks into logical units, only into somehting that is called "Primär Partition" which should be translated into something like "Single unit" or "Primary Partition", or Expanded Partition. How on earth do I make them Logical when the Logical option is dimmed down?

[BipolarBill]

The only way to create logical drives without primary and extended partitions is to use something like Partition Magic. It's not free.

Go ahead and create Primaries. Be sure that the drive you want to boot from is the master on IDE 1. Be sure to select the proper drive in the boot sequence in BIOS setup.

[Damodred]

thanks, all is working now :)

[Damodred]

A question has arrised....

After the raid5-array has been created do I need to do the synchronise that it wants to do? It fails after 36% cause it report a fault somewhere, but scandisk doesnt find anything. Now I tried to add a file to the array and it worked. So do I really need the first synchronising that it wants to do?

[BipolarBill]

Well, you haven't told us which controller you're using. Have you read the manual?

[Damodred]

oh hehe

Im using a q-tec controllercard together with the onboard manual. Thing is Im using software raid :) I know you told me not to use it but I couldnt resist atleast trying it out.

I have created the array now in win2003 server and it seem to work nice, still it always wants to do the synchornise thingy....

[BipolarBill]

Synchronization is for the 3rd (parity) drive. You aren't backed up until it's done.

[Damodred]

hmm I see
better do that then...thing is that it seem to hang up at 36% and stall there. Hmmm...thanks :)

[Damodred]

grrr I get so annoyed. Turns out that two of the new disks I bought fails of redundancy :( I have run checkdisk on it and it didnt find any problems :(Is there any way to make windows override this? Maybe not good but I believe windows is oversensitive :(

[BipolarBill]

Do you mean a cyclic redundancy error? Thats serious business. That means that data written to the drive is not the same when recovered from the drive.

You may need to update the adapter BIOS and drivers and then reinstall Windows.

http://www.qtec.info/service/support/drivers.htm?artnr=13237

[BipolarBill]

Don't assume that it's the disks. You bought a cheap RAID adapter. It's not really even RAID 5 - it's RAID 0+1. That would require 4 matching drives, which you probably don't have.

[Damodred]

well thing is the problem seem to move around upon restarting. It is never the same two harddrives that report faults....I dont understand :( Would it be better if I put 4 samsung diskson the controller and the two maxtors on the motherboard controller?

[BipolarBill]

I would.

[Damodred]

Ok I did that, still one of the Samsung disks reported problems. I removed the samsungdisk from the array-setup so now Im trying it with 5x160 instead of 6x160. Resynching going well and I have now also tried to write to the believed-to-be-broken disk which seem to work, altho Windows report the disk as "Healthy, at risk". I believe that if it works for me now I will send in the disk for replacement, the store I bought it from even sent me a RMA-handling together with the packages when the disks arrived :)

As for now mate, I thank you for all help.
regards
Damo

[Midknyte]

did you run the samsung hdd diagnostics? chkdsk ain't gonna cut it. why waste time trying to set up the array with bad drives?

are you doing software raid through windows or through the RAID card? raid5 in win2k cannot include the system/boot partitions, and I don't think that has changed in win2k3.

[Damodred]

yea I have (now) and it will be an RMA on it. Im aware of the system/boot thingy, Im using a Seagate Barracuda V for the OS.

[Damodred]

Can report now that Im running a raid5 array in software mode and its working perfect. Im getting about 80mb/sec readspeed according to Nero and Sisoft Sandra and about 15-18mb write speeds. A bit slow but not surprising. Is working great right now :)