PDA

View Full Version : Software Mirroring, controller question.

djnes
04-09-2007, 01:38 PM
I'm building a server for home, mainly as a file server. I have 2 WD 250 GB IDE drives (8 MB versions). If I had both of these drives on the same IDE channel, will I notice much of a difference as compared to the same drives each on a separate channel of a Promise ATA100 card? I'd plan to have them running a software mirrored setup, and the drives won't be holding the system volume.
Dan_D
04-09-2007, 02:12 PM
I'm building a server for home, mainly as a file server. I have 2 WD 250 GB IDE drives (8 MB versions). If I had both of these drives on the same IDE channel, will I notice much of a difference as compared to the same drives each on a separate channel of a Promise ATA100 card? I'd plan to have them running a software mirrored setup, and the drives won't be holding the system volume.

With IDE the slave will always be slower. So yes, you will see better performance by using the drives as masters on seperate channels. I do not know if the onboard or the Promise controllers will be faster however. Generally I avoid software RAID through the OS because it's not the best performer. Even hybrid-software RAID via the controllers BIOS is better than that as far as I am concerned.
djnes
04-09-2007, 02:39 PM
Performance isn't so much the issue. As long as it's functional. I'm mainly using it as a place for my wife to back up her digital photos in case her drive were to fail.
unhappy_mage
04-09-2007, 04:02 PM
Generally I avoid software RAID through the OS because it's not the best performer. Even hybrid-software RAID via the controllers BIOS is better than that as far as I am concerned.

Why?
Dan_D
04-09-2007, 07:33 PM
Why?

Performance of software RAID isn't exactly that great. Plus I prefer a BIOS to handle the creation and management of a volume.
unhappy_mage
04-09-2007, 07:50 PM
Performance of software RAID isn't exactly that great. Plus I prefer a BIOS to handle the creation and management of a volume.

If the raid is done at the driver level, there's nothing to make it faster than doing it in the OS. As for performance... well, we could argue a while on this. Suffice it to say I respectfully disagree, especially when the raid level is 0 or 1 or both.
tdg
04-09-2007, 09:49 PM
Definitely keep the drives on separate controllers if feasible, I tested a similar scenario myself and found a definite boost when mirrored array disks are kept separate channels when using IDE.

Also software RAID isn't too bad anymore with modern implementations, I used to be firmly against letting software take care of it, but nowadays I'm almost more towards software. I've been migrating my large RAID5 SCSI arrays with RAIDZ ZFS arrays, saves a lot of hardware cost of the card, and is actually much "smarter" than a hardware card in terms of being able to heal data corruption automatically, and faster rebuilds.
djnes
04-09-2007, 10:11 PM
I think I'll pop my old Ultra133 TX2 card in and use the drives on separate channels. I have an 80 GB SATA drive for the system volume, which is where any apps would run from, like SharePoint Services, etc. For the 2 storage drives, software RAID1 will be fine for me, because a small performance decrease will be fine. Having the data redundant across two drives is the primary goal. At most, 2 people will be using it at once...myself and my wife, so we won't be hitting the server very hard.