Help me plan my home server storage system

[Geofram]

I am looking for some advice for the best way to configure my hard drives in my home server. Here's the basics of the setup and what I've been doing.

Server running Windows Server Essentials 2012 R2. It runs on a Samsung 820 120 GB SSD, which just basically has the OS. I also have 6 x 3 TB WD Red drives. I also have 2 other 1.5 GB drives that are in the system, and 1 120 GB OCZ Vertex 2 that can be used wherever. I have an LSI 9240-8i RAID card.

What I'm trying to accomplish: All of the WD Reds in one large pool where all of my data resides. I'd like to maximize available space without making it dog slow. I also need to be able to expand it in the future as it fills up. I currently have just over 6TB of it used. It also needs to be able to handle at least one drive failing without losing data. I have an online backup solution where I'm doing the true backup, but I'd like to not have to restore terabytes of information just because one drive dies.

Things I've tried:

Originally I had the drives in a Windows Storage Space with Parity. It failed the "Dog slow" test, and also the "maximized space". When I looked at it, there was a lot of wasted space; more than RAID 5.

Next, I decided to try a combination of RAID and Storage spaced. I heard about Tiered Storage Spaces, so I threw in the 120 GB SSD and built a RAID 5 array (on the LSI) card out of the drives, then put the RAID array and the SSD in a "Simple" storage space with tiering enabled. This generally works, but it's still horribly slow at writing - the tier didn't help as much as I hoped. Reads are fast though. My worry with it is that the SSD tier is not mirrored, and I'm afraid that if the SSD died, it would take out the rest with it, because of how Storage Spaces works.

I'd like to get other ideas here of ways to try it. I must be able to handle losing a drive, any of the drives, without losing data. I *want* it to be faster than 50MB/s writes, but if there's no way to make it fast, so be it. I also must be able to expand it without taking it down, if I run out of free space (this is why I've been using Storage Spaces mainly).

One thing I would prefer not to hear about it Linux alternatives; I use the other functions of Windows Server Essentials (like the domain controller) so I need it to be compatible with Windows. I'd also be willing to spend some money for additional hardware, but not hundreds of dollars.

Anyone have any ideas?

 

[Cerb]

My worry with it is that the SSD tier is not mirrored, and I'm afraid that if the SSD died, it would take out the rest with it, because of how Storage Spaces works.

Doubtful. If it would do that, you should be getting very good write speeds. Still getting poor write speeds indicates either using the SSD as a read cache only (a write-through write cache would end up the same thing).

Now, is that 50MBps sequential, or random (including copying files of typical sizes you use, but not like big ISOs or anything)?

If it's random, and you need more performance, RAID 10 is the easiest option. All standard parity RAIDs have a write penalty, and the possibility for write speeds to go lower than a single drive. I think a different controller card would be needed to utilize SSD caching with the hardware RAID.

If that's 50MBps sequential, then there is likely a configuration problem somewhere, because you should be able to get 100MBps or thereabouts even w/o write caching on the controller, except in synthetic benches.

 

[Hellhammer]

The entry level LSI RAID cards are known for terrible RAID 5 write performance due to the processing power required by the parity calculations. 50MB/s is all you'll get in RAID 5, unfortunately.

EDIT: The LSI SAS 2008 IOC in your RAID card doesn't even support RAID 5, it relies on the host CPU for calculations.

In my opinion the best option here would be to RAID 10 the WD Reds. with 6x3TB, that'll yield a usable capacity of 9TB but you can increase that to 12TB later on. It's true that you "lose" more space for parity but on the other hand the whole array doesn't have to be rebuilt if one of the drives fails, which could take hours with TBs of data.

 

[BonzaiDuck]

The entry level LSI RAID cards are known for terrible RAID 5 write performance due to the processing power required by the parity calculations. 50MB/s is all you'll get in RAID 5, unfortunately.

EDIT: The LSI SAS 2008 IOC in your RAID card doesn't even support RAID 5, it relies on the host CPU for calculations.

In my opinion the best option here would be to RAID 10 the WD Reds. with 6x3TB, that'll yield a usable capacity of 9TB but you can increase that to 12TB later on. It's true that you "lose" more space for parity but on the other hand the whole array doesn't have to be rebuilt if one of the drives fails, which could take hours with TBs of data.

Server Essentials must be taking the place of the WHS OS's. I'm still using WHS-2011, upgraded from the first WHS.

Sometime earlier, I'd acquired a promotional copy of the full-blown Windows Server -- maybe before 2003. I had RAID5 in that box, but the hardware had gone on the fritz -- no data loss.

In the interim, I had just a Windows XP Pro running the same RAID but used as a server box. I finally went with WHS. The new version of WHS (and probably the last) requires a plug-in for drive pooling. I don't use RAID with that system, but the WHS supplies the redundancy I need.

And I can only speak from the WHS experience, but if you lose the OS -- sequestered on its own HDD, you shouldn't lose the data stored on your RAID array or drive pool. At least with WHS, I simply reinstalled the WHS at one time and everything else was miraculously restored.

 

[Geofram]

Doubtful. If it would do that, you should be getting very good write speeds. Still getting poor write speeds indicates either using the SSD as a read cache only (a write-through write cache would end up the same thing).

Now, is that 50MBps sequential, or random (including copying files of typical sizes you use, but not like big ISOs or anything)?

If it's random, and you need more performance, RAID 10 is the easiest option. All standard parity RAIDs have a write penalty, and the possibility for write speeds to go lower than a single drive. I think a different controller card would be needed to utilize SSD caching with the hardware RAID.

If that's 50MBps sequential, then there is likely a configuration problem somewhere, because you should be able to get 100MBps or thereabouts even w/o write caching on the controller, except in synthetic benches.

I'm not positive which it is. I'm basing this off of just flat out copying files over and watching the speed in windows, instead of synthetic benchmarks. So there are a lot of big files (movies) and a lot of small ones (pictures, etc). It wasn't consistent at how fast or slow it went, but if I had to average, I'd say it was around 50MBps.

In my opinion the best option here would be to RAID 10 the WD Reds. with 6x3TB, that'll yield a usable capacity of 9TB but you can increase that to 12TB later on. It's true that you "lose" more space for parity but on the other hand the whole array doesn't have to be rebuilt if one of the drives fails, which could take hours with TBs of data.

How would I expand it? I thought making any changes to a RAID would result in having to basically wipe out all the data and rebuild it.

 

[Cerb]

How would I expand it? I thought making any changes to a RAID would result in having to basically wipe out all the data and rebuild it.

That card supports online expansion. It's generally not a best practice, but LSI claims it's possible on your card, from what I read.