SSD mirroring to HDD in Windows software RAID?

[rising_suns]

Hello,
I have read that Windows 7 Professional (and above) has software RAID features, including a hard drive mirror function. I was wondering if anyone here has any experience using this. I am particularly interested in mirroring from a SSD to a HDD.

I know that traditional hard ware RAID setups require two or more identical disks. But I don't know if Windows software RAID has the same limitations, or is more versatile in this regard (?)

(ALSO HOPING TO KEEP TRIM SUPPORT FOR THE SSD)

Looking forward to your response.

 

[theevilsharpie]

If you mirror a SSD with an HDD, you subsequent array will have the performance characteristics of your HDD.

Since I am 99.99999% sure this is not what you want, then for your purposes, what you're trying to achieve is not possible with RAID.

Also, no RAID controller that I know of (hardware or software) requires two identical drives for a mirrored array.

 

[yinan]

This would not be a good idea. It is generally not a good idea to have the drives be that far apart in speed, things can get out of sync easily.

 

[corkyg]

Bad idea. My analogy would be like lashing a thorobred to a donkey. Together they could only run as fast as the donkey. Mirroring is best done with like drives.

I further suggest that this thread be moved to the Memory & Storage Forum.

 

[Nothinman]

Even Windows software RAID should be flexible enough to let you do that, but like the others said it'll likely suck pretty bad. And since you don't say what your actual end goal is, it's hard to recommend any other solutions.

 

[SimMike2]

I'll pile on. Not a good idea. Probably no performance gain while increasing the risk of losing your data. Kind of like recommending your date as: not very attractive but they make up for it by having a bad personality.

 

[Rifter]

do not do that.

 

[rising_suns]

Thank you for the comments thus far. I am not sure you have been clear enough; it almost sounds as if you are saying it is not a good idea.

Understood.

Regarding, TRIM support on Windows 7 software RAID, does it exist? If I were to mirror two SSD's in Windows, would I loose TRIM?


Thanks again for your upfront and honest candor.

.

 

[corkyg]

Regarding, TRIM support on Windows 7 software RAID, does it exist? If I were to mirror two SSD's in Windows, would I loose TRIM?

This thread and response by Holmes4 can guide you.
http://www.mydellmini.com/forum/windows-7/17239-enabling-trim-support-windows-7-a.html

 

[rising_suns]

This thread and response by Holmes4 can guide you.
http://www.mydellmini.com/forum/windows-7/17239-enabling-trim-support-windows-7-a.html

Thank you for the information, but the thread does not appear to answer my question. It only addresses enabling AHCI, which I already have set up. What I am more interested in, is finding out if using Windows software RAID will disable TRIM as it does with hardware RAID setups.

If not, then this could be a huge advantage to opting for the built-in Windows RAID over a different option.
.

 

[yinan]

If the only requirement of this is to protect the data, why not write a script that syncs the important data regularly?

 

[rising_suns]

If the only requirement of this is to protect the data, why not write a script that syncs the important data regularly?

Sync software would not work for me; I have tried numerous packages already. It requires too much processor, and bogs down the system.

The data that I need to mirror is large; about 1 TB in size, which changes every day. This is why I am considering either a Windows option (don't know if it would be any faster?), or moving to hardware (although I would like to avoid losing TRIM).

.

 

[mtnd3vil]

Use windows backup to schedule a nightly full backup of all the data on the SSD to the HDD. From my understanding of your goals, this will be a perfect solution for you. Every single file on the C: drive will be captured by this backup including additional features like system state and bare metal recovery. You should also end up with multiple dates to restore from. You will be able to do individual file level restores too. Check it out!

 

[RebateMonger]

The data that I need to mirror is large; about 1 TB in size, which changes every day.

You are using a 1 TB SSD?

 

[rising_suns]

Thank you for the suggestion, but I have already tried that as well. These computers run processes throughout the night using Windows Automation software, which requires a stable PC with no interruptions in the demand made on processor. Any Windows based backup software is out of the question, since it requires too many resources, and thus causes numerous errors in Windows automation.

Yes, I would be using a 1 TB SSD...or rather, perhaps a 512 GB to save on costs.

 

[Greg1975]

I came to this thread trying to see if Windows supports this exact setup. I think the poster's question is legit and most of the other answers are garbage (or "short-sighted" if you prefer), here's why:

SSD read speed with HDD reliability at the cost of HDD write speed. This is massively beneficial for most people. Now, I researched this on the Linux side first, and in Linux this is fully supported. Underlying metadisk volumes can be specified to be read-shy (eg HDD) so reads are pulled from the SSD. This is exactly what I want, but I am running Windows. That's how I found this thread. Why did I research Linux in the first place? I work in both and I knew that Windows tends to be years behind Linux in anything i/o or anything highly flexible at the system level (sorry, but it's true). This only proves the case. On the Linux threads, I got answers. Here we get a bunch of nay-sayers claiming it's a bad idea. What???!!! How is this possibly a bad idea? You ASSUME it's a bad idea because you are inherently imposing your view on how raid SHOULD work just because that's how it traditionally worked. Terrible. Especially considering that tiered storage is growing in leaps and bounds in the enterprise.

Hopefully, there's still the possibility of a flexible windows driver for this to be found somewhere out there... I for one am not settling for the answers in this thread. If someone does find a solution, please post it. This will help others also searching for how to do this.

fwiw - You could do this on a Linux box and offer it to windows over LAN via AoE or iSCSI. That would be a performance hit, though.

Greg

 

[Greg1975]

The data that I need to mirror is large; about 1 TB in size, which changes every day.

This could be done via a Raid 0 stripe using smaller SSDs to provide the 1TB SSD volume for that half of the SSD-HDD raid mirror. This is what I was planning to do if I resort to Linux. (4 x 120GB SSD + 1 x ~500 GB HDD) If you cap the HDD side to 440 GB or so then you can probably get better wear leveling from the SSDs since you won't use full capacity.

 

[corkyg]

The question was about mirroring, i.e., RAID1. And the environment was Windows 7 Pro. RAID0 and Linux may work as you say, but it has nothing to do with the original thread and your so-called "garbage." RTFP!

 

[Matt2k]

I know this thread is old, but it comes up as one of the first results in google "Mirror SSD to HDD".

There is no shame in admitting you don't know the answer to a question, and in fact offering up advice in that situation as fact is detrimental. This thread is a perfect example of that. The posts here are simply flat out wrong. I mirrored my SSD to my magnetic drive and the results are in:

. Read performance of the SSD
. Write performance of the traditional hard drive

This is exactly what I wanted. I now have a pretty great combination of performance and reliability. I hope this helps others in future searches.

. Win 7 software mirror
. Primary SSD
. Secondary magnetic

 

[jonmelvin]

I just saw the post below. Very nice. Thanks for doing the experiment Matt2K. It is useful to mirror for the following, which I am considering:
Use SSD for enterprise database application
To get arround chance of loss of failure, besides backing up, replace
SSD frequently (say every 6 months) by mirroring to a new SSD and
then removing the old SSD and breaking the mirror
Much less expensive than arrays of 15K SAS drives, or enterprise SSDs.
Just a thought.

JDM

I know this thread is old, but it comes up as one of the first results in google "Mirror SSD to HDD".

There is no shame in admitting you don't know the answer to a question, and in fact offering up advice in that situation as fact is detrimental. This thread is a perfect example of that. The posts here are simply flat out wrong. I mirrored my SSD to my magnetic drive and the results are in:

. Read performance of the SSD
. Write performance of the traditional hard drive

This is exactly what I wanted. I now have a pretty great combination of performance and reliability. I hope this helps others in future searches.

. Win 7 software mirror
. Primary SSD
. Secondary magnetic