RAID 1 advice

MrXpert

I need some PC help. On my Windows 7 box I've got two Seagate 500GB drives operating in RAID 1. I'm slowly running out of space so want to upgrade to at least 1TB. Is it possible for me to remove one of the old 500GB drives and put in a 1TB and have the data including the OS be copied over to the new drive? assuming this is possible can I then remove the second 500GB drive and replace it with another 1TB drive and have the raid array rebuilt so that I am now using 2x1TB drives and did not have to reinstall windows?

It is software RAID I have which is powered by the mobo. This is obviously slow compared to hardware based raid. I'm wondering if the better option maybe to just put in 2 1TB drives and not bother with RAID and just use the other drive as a backup. What do you think?

Unfortunately I can't afford a dedicated decent RAID PCI-e card. Too much for my wallet.
thanks

dbrink

Is it possible for you to just put 2x1TB drives in your system and mirror them. Then just move data over to it and not have to reinstall the OS? That would give you a 500GB drive for the OS and then a 1 TB drive for data.

ptilsen

This will depend on the motherboard. With most RAID 1 solutions, you can indeed swap a drive for a larger one, allow a rebuild, then swap the remaining small drive for another large one. You may or may not have to use the newly-provided free space as a separate virtual volume ('virtual" is presented to the OS as a "physical", generally speaking), depending on the RAID system. I would just try it. If your RAID 1 is working at all, the worst that could happen is that it won't let you make the new array with the 1TB. If the RAID isn't working, the whole thing is moot. I would take a backup no matter what before doing any drive changes.

As far as performance, you'll be disappointed with the differences between software, firmware, and hardware RAID 1. Typically, firmware RAID (that provided by a motherboard or card which doesn't have its own processor for RAID calculations) performs identically to software RAID. In the case of modern Windows 7/8 systems and many other operating systems, it will actually perform worse. In the case of RAID 1 specifically, hardware controllers provide a trivial performance boost at best. Because RAID 1 is only mirroring, the CPU operations required to support it are negligible. As a result, latency, throughput, and RAID-induced CPU utilization are also negligible.

By comparison, RAID 5 performs substantially worse in software/firmware implementations no matter the processor or the quality of the software. Significant latency and throughput reduction occurs when there isn't a dedicated parity processor. Anyway, none of this is altogether that relevant since you are using RAID 1. My point is that you don't need a RAID card for this at all, and there would be negligible benefits to getting one. Better to save your money for an SSD and only use that big RAID 1 array for bulk storage.

jdancer

To make your life easier in the future, you may want to consider putting the operating system in it's own storage device. With my server, only the data is mirrored, the operating system runs off a SSD.

lsud00d

Coherd on the OS SSD data HDD config

MrXpert

This is such good advice from all of you. its definately given me more to think about and what is best would probably be an SSD for the OS and RAID 1 for data. Now to go look at some drives! hehe!