my awsome idea for RAID

[Jskid]

I was thinking of a setup and was wondering if there's any ways this can be improved.

2x SSD at RAID level 0 - fast for OS and applications
2x HDD at RAID level 1 - backup for data

NOTE: I'm not talking of RAID 1+0 I'm talking about independent 1 and 0.

 

[Coup27]

I opened this thread thinking there would be an awesome idea for RAID.

 

[Jskid]

I opened this thread thinking there would be an awesome idea for RAID.

You don't like it?

 

[Charles Kozierok]

Pretty sound idea in general.

I personally wouldn't bother with the RAID 0 array. I mean, do you really need that extra incremental performance, enough to justify the cost and the bother of dealing with extra hassle if it fails? But that's me, I tend to be conservative on such matters.

 

[serpretetsky]

looks fine. the raid-0 on the 2x ssd's might be pointless depending on your applications. It may be better to just get a single larger ssd (that will most likely be faster overall anyways)

 

[Coup27]

You don't like it?

It's not that I don't like it, I am just not sure what people will be able to add to it. You clearly understand the benefits and differences between the RAID levels and you are mixing SSD and HDD so you cannot do a RAID5 across the lot so it's pretty much a done deal.

Obviously the RAID1 on your data is not a backup, but an extra layer of redundancy should one of the drives fail. Do not substitute that for a proper backup.

 

[Jskid]

Many smaller SSDs are faster than larger ones e.g. http://www.newegg.com/Product/Produc...82E16820167042
Also I care more about the speed of the SSD in RAID 0 since I'd have a large HD for my data.

 

[Charles Kozierok]

Also I care more about the speed of the SSD in RAID 0 since I'd have a large HD for my data.

Then it sounds like you've got it figured out.

 

[Railgun]

How about:

4x SSD in 0
4x HDD in 10

 

[kbp]

I have a question about over provisioning. I broke a raid-0 array that was over provisioned. Secure erased. But now windows will only show me the "provisioned" drive space. My question is - how do I "break" the over provision partition? A full secure erase does not do it.

 

[Jskid]

How about:

4x SSD in 0
4x HDD in 10

Any reason you choose 4 SSD, not 3 or 5?
I thought about
2x SSD in 0 - apps and OS
3x HDD in 5 - data (this has speed and redundancy benefits)
However I don't think adding another drive to jump from level 1 to 5 is cost efficient, especially when you're just storing data.

 

[Coup27]

I thought he was just taking the piss tbh

 

[serpretetsky]

Many smaller SSDs are faster than larger ones e.g. http://www.newegg.com/Product/Produc...82E16820167042
Also I care more about the speed of the SSD in RAID 0 since I'd have a large HD for my data.

There are a lot of a different numbers you can analyze for hard drive speeds.
RAID-0 will typically increase sequential read and write quite a bit. However, usually RAID-0 does not increase (and sometimes decreases!) 4k random reads/writes at low que depths.
http://www.storagereview.com/crucial_m4_ssd_raid_review
4k random reads/writes is where SSD's obliterate spinning disk drives, and its where a large amount of their speed increase is felt. On the server side, usually 4k read/writes are very important at high que depths, which is where raid-0 may see an increase, but on the consumer side, high que depth 4k reads/writes aren't as important.

So unfortunetly its not black and white, and its why i said it depends on your applications.

I'm not very familiar with current SSD's, so hopefully someone else will jump in, but as an example:
http://www.newegg.com/Product/Produc...82E16820147164
this drive here will
1) cost you less than 2x intel 510's 120gbs
2) probably have faster 4k reads/writes than 2x intel 510's

I haven't kept up with intel, but I think the 520 240gb may be a good choice (although i think the samsung is cheaper)

Also, one more thing about raid and ssd's. Keep in mind that some ssd's depend on the trim command sent from the OS to keep their perforamance at peak levels, i know intel has heavily depended on trim before (do they still?) while others use some passive garbage collection that doesn't depend on the OS to send a trim command.

There is nothing wrong with an ssd that heavily depends on the trim commands, except that RAID currently doesn't support any trim commands.

 

[Jskid]

There is nothing wrong with an ssd that heavily depends on the trim commands, except that RAID currently doesn't support any trim commands.

How much could this slow the drive down? This could be a deal breaker Just to be clear on what your saying, Intel doesn't have passive garbage collections? Virtually all SSD I've seen have TRIM, wouldn't this imply they don't have passive garbage collecting?

 

[zephyrprime]

Get a revodrive. It's basically raid out of the box and a better implementation than a manual setup. Every raid controller in existence will have troubles keeping up with modern SSDs.

 

[Railgun]

Any reason you choose 4 SSD, not 3 or 5?
I thought about
2x SSD in 0 - apps and OS
3x HDD in 5 - data (this has speed and redundancy benefits)
However I don't think adding another drive to jump from level 1 to 5 is cost efficient, especially when you're just storing data.

I thought he was just taking the piss tbh

Heh. I was and I wasn't...the latter only because that's that I'm actually running.

10 has better write performance and I'll take the marginal hit on read.

 

[Railgun]

Every raid controller in existence will have troubles keeping up with modern SSDs.

I think you may be having trouble keeping up with controller tech. Modern SAS/SATA controllers won't break a sweat with SSDs. The limiting factor in some cases is PCI-E bus bandwidth, especially since a lot come in x8 versions. ATTO benchmarks, while not the end all be all, will peak at 4GBps with the right setup.

I run an Areca 1880-i and, while it's fantastic, is limited not by itself, but the bus (not that in real world usage you'll hit that anyway).

 

[serpretetsky]

How much could this slow the drive down? This could be a deal breaker Just to be clear on what your saying, Intel doesn't have passive garbage collections? Virtually all SSD I've seen have TRIM, wouldn't this imply they don't have passive garbage collecting?

They are not exclusive, you can have both. Most ssd's have fairly decent passive garbage collection, but I'm fairly certain the intel x25-m's, for example, only had trim, no passive garbage collection. The x25-m is a pretty old ssd, so they may have changed.

 

[VirtualLarry]

I have a question about over provisioning. I broke a raid-0 array that was over provisioned. Secure erased. But now windows will only show me the "provisioned" drive space. My question is - how do I "break" the over provision partition? A full secure erase does not do it.

If it's an Intel drive, then you need to do a "SET MAX LBA" command, to re-size the drive to full size (essentially, removing HPA), and then do a full secure erase.

For other mfgs/brands drives, I have no idea.

 

[Zap]

I was thinking of a setup and was wondering if there's any ways this can be improved.

2x SSD at RAID level 0 - fast for OS and applications
2x HDD at RAID level 1 - backup for data

NOTE: I'm not talking of RAID 1+0 I'm talking about independent 1 and 0.

Are you saying that you are storing data on the HDD RAID array, or you are using the HDD RAID array to back up the same data that is on your SSD RAID array? If it is the former (just to hold data) then it is NOT a backup. You'd be surprised how much data can be lost due to malware or even just the file system screwing up. RAID1 will not help in those instances.

 

[Smoblikat]

You don't like it?

Its not exactly awesome. I have 4 10K RPM velociraptors shortstroked in RAID0 and I dont even consider that awesome. Your idea is very standard.

 

[KillerBee]

Its not exactly awesome. I have 4 10K RPM velociraptors shortstroked in RAID0 and I dont even consider that awesome. Your idea is very standard.

I've never understood the shortstroking thinking ..just seems like a waste of disk space
ie: don't you get the same effect if you made 2 partitions?

 

[Zap]

I've never understood the shortstroking thinking ..just seems like a waste of disk space
ie: don't you get the same effect if you made 2 partitions?

No. The point of short stroking is to do 2 things:
1) Keep the data in the fastest portion of the disk.
2) Keep the head from having to move over the whole disk.

Or, just get an SSD. :sneaky:

 

[KillerBee]

Just to be clear on what I think short stroking is:
Take a 600GB drive and short stroking it to a 300GB drive

vs creating (2) 300GB partitions - use the 1st 300GB the same as above
but still have the extra 300GB available for whatever

Is the short stroked drive that much faster than the 1st 300GB partition?

 

[Dark Shroud]

How much could this slow the drive down? This could be a deal breaker Just to be clear on what your saying, Intel doesn't have passive garbage collections? Virtually all SSD I've seen have TRIM, wouldn't this imply they don't have passive garbage collecting?

TRIM does not work with RAID, it's that simple. Over time this will degrade the drive's performance even with garbage collection.

Just get yourself a OCZ RevoDrive 3 series that does support TRIM. This will give you the performance you're looking for.