RAID 5 PCI card (1 Viewer)

[eetaylog]

can someone please recommend a decent 4 port Sata PCI card that supports RAID5.

ive found this one on ebay, but wanted to see if enyone has any other recommendations beofre i part with my cash.

clicky...

thanks

 

[jaymode]

That is a software raid card. I would recommend getting a hardware card if you are serious about raid 5. I personally use a 3ware 9550. It is a 64bit PCI-X card but it works in a regular 32 bit pci slot, which is how I run it.

 

[eetaylog]

whats the difference? i thought that software controlled RAID setups were the onboard kind, and expansion cards were hardware based?

why is hardware based raid better than software based?

thanks again.

 

[milhouse]

I would actually consider software RAID for home use. Not through a software RAID card, but at the OS level (software RAID in Win 2003 Server or Linux) so you need only SATA ports, and not a RAID card.

I use software RAID under Win 2k3 Server. I have a 8x500GB array and a 5x640GB array.

Here's my logic:
-Since I store media on my arrays, it's write one, read many. So the performance hit doesn't bother me.
-It's home use, and $$ is limited. A good hardware RAID card i pricey (esp for the 24 port variety I need on my server). It was cheaper for me to get 2 8-port PCI-X SATA cards (plus the 6 on-board the MB) to support all the bays on my server.
Here's the cards I have: http://www.newegg.com/Product/Product.aspx?Item=N82E16815121009
-When a HW RAID card goes bad, you generally need to find the same card to salvage the data - unexpected, high $$ outlay when things go bad. With software RAID, you move the whole array to a different computer and it Just Works (r).

My two cents.

 

[eetaylog]

looking at their prices theres no way i can afford a hardware card, so if theres not much issue with reliability i would rather just choose a cheap software based one because the server isnt going to be under much stress given that i only have one htpc connected to it.

currently im actually only running 4 x 500Gb drives as RAID0, so i wont need any more than 4 sata ports (im running the OS off a smaller 80Gb HD plugged into the onboard sata ports, so the raid setup is purely for storage), plus the fact that i dont have any more power supply connection from my psu.
ive got a feeling that one of my disks in the current RAID0 may be on its way out, so i want to setup a RAID5 array and move everything across before its too late!

questions:

1. is it possible to just swap a new pci raid controller over for my old one, and just carry on as normal (i want to test whether the old card is at fault before i get into the expensive business of buying more drives to setup raid5)?

2. is it possible to use different sized disks in a RAID5 array?

thanks for your input guys, keep it coming

 

[milhouse]

If your current RAID0 array is software in Windows, using dynanmic disks, then the RAID information is stored on the disks themselves. So swapping the card out would not be a problem.

If it's HW, then it'd be a problem.

If Disk Manager sees 4 disks, that's the indication that you are in good shape to change out cards.

(I won't speak to HW or Linux, as I am quite unfamiliar.)


With regard to your second question - yes, it is possible. But the space available is (n-1)*size of smallest drive. For example, if you used a 320 + 4*500, the RAID array would be of size 4*320, and you'd have some unallocated space.

 

[eetaylog]

thanks for that. im pretty sure its a software based card as the bootup screen displays 4 harddrives briefly when i switch the server on.

so youre saying that its actually pretty pointless adding different (larger) disks to an already existing RAID5, if for example one of the disks dies, as you dont actually get to use the extra space anyway?

one last question regarding PSU's... with my current setup, all my PSU connectors are being used, leaving no room for expansion. how do people manage to power larger numbers of HDD's?? ive seen server setups with anything up to around 12 disks! surely you cant just add more PSU's because the computer has to have common ground doesnt it?

 

[moab]

I have 2 PCs with hardware RAID. The PCs were bought off ebay for < $300 as damaged but working PCs. It comes "built-in" on some motherboards. I have 2 HP M7674n PCs that have the Asus Basswood motherboard.

RAID was disabled by default.
Step 1 was to create a set of OS recovery DVDs. This can be done during boot (F11 I think).
Step 2 to enable RAID you need at least 2 HDD (obviously) then go into RAID bios using CTL-I during boot. This option appears after the usual F2 for BIOS set up in the DOS boot screen. Once in the RAID controller menu I set up a RAID 0 array for my 2 drives. This erased all data on the 2 drives (including the recovery partition - so it is essential to have the recovery DVDs.
Step 3 insert restore DVD 1.
Step 4 reboot the PC with the recovery DVD disk 1 and follow instructions. I got some error duing the recovery after putting in a disk. I just re-inserted the disk and retried a couple of times and it finally took the restore disk. I think it was a timing bug in the restore program.
Step 5 after restore complete then reboot and be ready to be amazed by twice as fast fast boot time.

The RAID is based on the Intel chipset and is the Intel RAID controller implemented by Asus on the HP Basswood motherboard. There are some updates for the Intel RAID software that can be downloaded from Intel. So far it has been rock solid with no RAID errors.
As I was skeptical that my $280 PCs had genuine RAID I downloaded some disk i/o software which confirmed the improvement in disk read times (i.e. twice as fast!). I didn't see any major CPU spike either so I was pleasantly surprised. No doubt it is not as good as a $500 PCI card but for free it is an amazing deal!
So my advice is check your motherboard spec to see if it is already in it. If not then off to ebay and get a cheap PC that has built in RAID on the motherboard or upgrade you motherboard to one with built in RAID.

I would never use Microsoft software RAID as the CPU performance hit is not worth it. This is well documented on the net.

Good luck!

 

[Gixxer]

very usefull information milhouse, thanks. ive learned some stuff here, for when i need one. so far i still have sata connectors free in the mb.

thanks for that. im pretty sure its a software based card as the bootup screen displays 4 harddrives briefly when i switch the server on.

so youre saying that its actually pretty pointless adding different (larger) disks to an already existing RAID5, if for example one of the disks dies, as you dont actually get to use the extra space anyway?

one last question regarding PSU's... with my current setup, all my PSU connectors are being used, leaving no room for expansion. how do people manage to power larger numbers of HDD's?? ive seen server setups with anything up to around 12 disks! surely you cant just add more PSU's because the computer has to have common ground doesnt it?

i belief you can use various psu. pretty sure infact.

just need to find the 2 wires to join and the psu will turn on.

 

[ryan20021982]

just need to find the 2 wires to join and the psu will turn on.

Jump from the green wire to 1 of the black wires on the motherboard plug