hard drive controllers

[aaronlalonde]

I just finished my new server- Intel q6600, 4gb ram Gb motherboard and xp pro 64 bit ( all I had available)

becasue this is 64 bit I cannot make stripe sets. I have two 500 gb drives I would like to use for recording ( have one client, one hd100 and two hd200 on the way) and am currently only using one drive.

I also need to build some sort of redundant array. I lost 14gigs of mp3 several gigs of photos and all my ripped dvd's when the hurricane took our power out for 2 weeks.

What would the masses suggest for
a. the recording array
b. redundant storage for important static content.

thanks!

[S_M_E]

Originally Posted by aaronlalonde

What would the masses suggest for
a. the recording array
b. redundant storage for important static content.

I would suggest WHS as the OS instead of using a RAID array. My music, photos and DVD backups are all on duplicated shares and I'm not worried about losing data at all anymore.

[stanger89]

I wouldn't bother with an array for the recordings. An array won't give you any benefit because after a while the drives get fragmented and the limiting factor is access time, not sequential transfer rate (which arrays improve).

As far as redundant storage, guess it all depends on how much you need. If you need less than 1.5TB (1 of largest drive available), I'd just get 2 HDDs and do RAID-0 through software/firmware/motherboard, or heck, just simple periodic copying to an extra drive.

If you need much more than 1.5TB, I'd start looking at a good hardware RAID card. I've got about 4TB of space right now, pretty much all full, so I'm sort of planning new array. Right now I'm looking at either a 3ware 9690SA-8, or an Adaptec 5805, and probably 4, 1.5TB drives to start.

[stanger89]

Originally Posted by S_M_E

I would suggest WHS as the OS instead of using a RAID array. My music, photos and DVD backups are all on duplicated shares and I'm not worried about losing data at all anymore.

WHS's duplication sounds really great, until you start doing the math. WHS's redundancy means you every byte you write requires another byte for redundancy. It's OK if you've got a relatively small amount of data. But if you start getting into terabytes of data, especially over 3, the cost of the drives it takes to achieve that redundancy becomes quite prohibitive, more than the cost of a good RAID controller.

Beyond that there's the logistics of mounting and powering the extra drives.

[davephan]

If you don't have a lot of files to backup, you might consider a free utility called Microsoft SyncToy. It can be setup to automatically copy files from one directory to another.

Another method would be to setup a batch file to automatically copy files triggered by the free DirMon2 utility that monitors directories for changes.

Yet another way is to invest in a RAID controller. Some mobos have RAID controllers built-in. Usually RAID does protect files, however RAID can fail. I have seen it happen at work because there are hundreds of servers and thousands of drives, we have to recover servers from backups on those rare cases. It's great to have multiple methods to recover, rather than one method to few! To be very confident of a successful restoration in business you need to have 3 or more methods to recover files and systems.

A hot spare in a RAID setup can improve data protection quite a bit. RAID 6 has a high overhead cost, but can withstand two drive failures at the same time.

I think the easiest and cheapest way to protect critical files for home use is to copy files to another hard drive, even if you use RAID. If possible, the backup hard drive should be stored off-site at another location. It's also important to use disk imaging so you can recover your computer if you loose your boot drive. Backing up the critical files to CDs and DVDs is not a good choice for long term storage. I have seen many recoveries from old CDs or DVDs fail. It's far more reliable to store the backups on hard drives. Tape backup and recovery is also very reliable, but it costs too much for home use.

Once you get accustom to SageTV, you will want to be able to recover quickly, with as little downtime as possible.


Dave

[S_M_E]

Originally Posted by stanger89

But if you start getting into terabytes of data, especially over 3, the cost of the drives it takes to achieve that redundancy becomes quite prohibitive, more than the cost of a good RAID controller.

The problem with *that* logic is that when you add drives to WHS you don't lose space to the array, it's all used. If you add 4 drives to WHS all of the space is available and you don't have to buy a RAID controller.

Not so with RAID arrays, with the exception of stripes which offer no redundancy, just performance. With a 4 drive mirror, you lose half of your space because the other half...is mirrored. With a 4 drive RAID5 array, you lose 1 disk (25%) to parity.

Either way you do it, if you have redundancy, it's going to double your used space. The difference is; with WHS you don't waste any of your hard drives to an array and you don't have to use matching drives. With RAID, the space of 1 or more drives is lost to the array. My WHS box uses 250G, 320G (system drive), 500G and 1T drives and I can use all of the space. When I get low on space I can change one of the 250G's for a 1.5T drive, on the fly, without breaking an array or losing data.

WHS makes more sense for Sage than you give it credit for, imo....

[CarlR]

Originally Posted by aaronlalonde

What would the masses suggest for
a. the recording array
b. redundant storage for important static content.

thanks!

Any complete backup solution needs to include offside storage. I use Carbonite, but there are several others out there that will let you store an unlimited amount of data for a reasonable fee ($50/yr). I'm a little concerned about security, so I encrypt the files locally (to a 2nd drive) and send the encrypted versions to the internet backup. The locally encrypted files also serve as a local backup mirror. I'm only talking about 100G or so of data, so it's just not worth setting up a RAID for that - it's easier to buy 2 drives and do a mirror.

[stanger89]

Originally Posted by S_M_E

The problem with *that* logic is that when you add drives to WHS you don't lose space to the array, it's all used. If you add 4 drives to WHS all of the space is available and you don't have to buy a RAID controller.

Yes but if you turn on Duplication on all your data in the pool, your data takes 2x as much space because everything is written to two discs in the pool.

Not so with RAID arrays, with the exception of stripes which offer no redundancy, just performance. With a 4 drive mirror, you lose half of your space because the other half...is mirrored. With a 4 drive RAID5 array, you lose 1 disk (25%) to parity.

And in WHS with Duplication turned on your data takes up 100% more space.

Either way you do it, if you have redundancy, it's going to double your used space.

Not true, RAID-5 provides redundancy and only costs you 1/n your space.

The difference is; with WHS you don't waste any of your hard drives to an array and you don't have to use matching drives. With RAID, the space of 1 or more drives is lost to the array.

Yes, the space of 1 drive is lost to redundancy, but the data isn't duplicated. As an example, say you've got 4, 1TB drives in each of two PCs. PC1 has the drives in a WHS pool with Duplication enabled, it displays 4TB available. PC2 has the drives in a RAID-5 array, it displays 3TB available and the remaining 1TB is consumed by parity information.

You write a 50GB Blu-ray rip to both PCs. On the WHS machine the pool writes that 50GB file to two discs using 100GB of your 4TB. On the RAID-5 machine, the 50GB file takes only 50GB of your 3TB (the redundancy comes from teh parity).

So between the two arrays:
In a WHS pool with duplication, you can store 40, 50GB Blu-ray rips.
In a RAID-5 array, you can store 60, 50GB Blu-ray rips.
You can store 50% more data on a 4 drive RAID-5 array, than you can on the same 4 drives in a WHS pool with Duplication enabled.

The situation gets even worse as the number of drives increases. With 6 drives, you get 67% more useable space with RAID-5, 8 drives = 75%, 10 drives = 80%.

My WHS box uses 250G, 320G (system drive), 500G and 1T drives and I can use all of the space.

But if you've got duplication enabled (for redundancy) you can't really. Everything you write to the pool is written to two discs, so it takes double the space. Effectively, with Duplication enabled you can only use, at most, half your space.

Further, I'm pretty sure there are situations where WHS would be unable to duplicate your data, like if you had a 250GB system drive, and 500GB and 1.5TB drives in the pool, I think over 1TB of data would be unable to be duplicated.

When I get low on space I can change one of the 250G's for a 1.5T drive, on the fly, without breaking an array or losing data.

WHS makes more sense for Sage than you give it credit for, imo....

FWIW, I was very excited when WHS was announced. I like the idea of the pool. I initially thought it was like unRAID, where parity was used. But upon research I discovered that WHS simply writes Duplicated data to two discs in the pool thus making it only 50% storage efficient with redundancy, compared to 75% or better with RAID-5. If you need to store TBs of data with redundancy, the cost of drives in a WHS configuration becomes quite prohibitive.

[Beefcake550]

While stanger89 is correct of what he writes, I wanted to add one comment that I didn't see mentioned....

If my RAID controller dies, it can be diffidult to find a suitable replacement such as not to loose any data. I have no personal experience with this, so I don't want to create FUD. This is jsut a thought in my head.

However, if any other hardware in my WHS machine goes nuts (including one of the drives my duplicated data was written to), I can take the drives in the WHS drive pool, plug them into another PC and read the data off of it. Very simple way to retrieve data (and fast).

Of course, both situations assume the hardware other than the hard drives themselves don't "take out" the data you are looking to recoup.

Stanger89 is right that the RAID setup will spend less bits giving you the redundancy, the trade-off there is the amount of time it will take to get at the data should somethign go wrong (the situation it's trying to protect against).

The WHS setup will take more bits (especially as the amount of data increases) to get the protection, but it is also quite easy to recover said data should something go wrong.

So, look at how much data you have and then decide which situation is best for you.

Personally, I have about 50-100GB of data that is not replaceable (photos, home videos, etc). I went with a RAID5 setup for these because I had the RAID5 controller (Areca 1210) before WHS came out. I tried WHS, but it couldn't perform my other server needs to my liking (try to place a particular file on a particular physical drive in the pool - you can't). That last issue causes performance problems I can't tolerate. If they fix that, I will likely move back to WHS from my current Vista Ultimate install.

Oh yeah, and don't put off gettign some online backup line I have so far for the irreplaceable data. I've been meaning to sign up for carbonite for the longest time.

[Skirge01]

Might I suggest taking a look at FlexRAID? I haven't implemented it yet, but I'm very close since my media server is nearing a "functional" stage.

Like you, I originally planned for redundancy in my server, but I quickly found that hardware RAID is not the answer due to there being no real standards. If you move from one motherboard to another or from one RAID card to another, there's no guarantee that the replacement hardware will be able to recognize the array and reconstruct the data, even within the same manufacturer! I've gone down this path before on my home computer, using onboard RAID, and the time spent trying to migrate the data and/or recover it was absolutely ridiculous. (BTW, this also highlights the fact that RAID is not a backup solution, it's an availability solution, which means it's meant to keep data accessible to users during a temporary/minor hardware failure.)

[S_M_E]

Originally Posted by stanger89

Yes but if you turn on Duplication on all your data in the pool, your data takes 2x as much space because everything is written to two discs in the pool.

That would be true with RAID too...

And in WHS with Duplication turned on your data takes up 100% more space.

See above, same with RAID due to the cost of the array in disk space...

Not true, RAID-5 provides redundancy and only costs you 1/n your space.

1n +1 complete drive to parity, you're trying to argue semantics. Either way RAID or WHS it's going to cost space for redundancy.

PC1 has the drives in a WHS pool with Duplication enabled, it displays 4TB available. PC2 has the drives in a RAID-5 array, it displays 3TB available and the remaining 1TB is consumed by parity information.

You write a 50GB Blu-ray rip to both PCs. On the WHS machine the pool writes that 50GB file to two discs using 100GB of your 4TB. On the RAID-5 machine, the 50GB file takes only 50GB of your 3TB (the redundancy comes from teh parity).

Which leaves 3T on the WHS (which is what the RAID started with due to parity) and 2.5T on the array. You're right, in that scenario (3T vs 2T), if there was more data written but the money you save on a controller (especially a larger one) you can put to drives.

But if you've got duplication enabled (for redundancy) you can't really. Everything you write to the pool is written to two discs, so it takes double the space. Effectively, with Duplication enabled you can only use, at most, half your space.

Again, semantics, I do use all of the space in you first example; I use 50G for the rip and 50G for duplication. What I'm not losing is space to an array only to the files I want duplicated. Additionally, while you CAN enable duplication on all of your shares, you certainly don't have to.

Further, I'm pretty sure there are situations where WHS would be unable to duplicate your data, like if you had a 250GB system drive, and 500GB and 1.5TB drives in the pool, I think over 1TB of data would be unable to be duplicated.

If you added another 1T drive (for a total of 4 drives) to your list; all of the data *could* be duplicated and you'd have 3T in you pool but, in that situation, you cant make a RAID 5 or mirrored array with those drives at all. With WHS you can *and* when the new 4T (or whatever) drives are available you can add 1 without have to add 3+ to make a RAID5 array.

FWIW, I was very excited when WHS was announced. I like the idea of the pool. I initially thought it was like unRAID, where parity was used. But upon research I discovered that WHS simply writes Duplicated data to two discs in the pool thus making it only 50% storage efficient with redundancy, compared to 75% or better with RAID-5. If you need to store TBs of data with redundancy, the cost of drives in a WHS configuration becomes quite prohibitive.

I still disagree. The cost of large controllers, being forced to use matching disks, losing one or more drives to parity (for larger arrays) and as Beefcake550 rightly mentions, if your RAID controller dies you could lose your data anyway and if a drive dies it takes a LONG time to rebuild the array.

With WHS you get more than just simple storage with the OPTION of duplication, you get backups, remote access to your shares and to your client PC's on your home network, you get built in media streaming, you can add drives that are not the same size so you can skip the expensive large controller(s), and you get easy expandability that's only limited to the ports (SATA, PATA, USB/FW all work and can be added to the pool) available on your HW.

My current WHS/Sage box has 7 drives and without adding any extra controller(s) I could add 12 more drives (1 e-sata, 1 SATA, 8 USB and 2 FW) if I needed and the drives could be any size. How much would it cost for a RAID controller that can handle 19 drives and how many of those drives would you lose to parity? WHS is far more flexible.

Again, imo, WHS is better suited for Sage in the home than you give it credit for...

[Taddeusz]

Originally Posted by S_M_E

I still disagree. The cost of large controllers, being forced to use matching disks, losing one or more drives to parity (for larger arrays) and as Beefcake550 rightly mentions, if your RAID controller dies you could lose your data anyway and if a drive dies it takes a LONG time to rebuild the array.

I really don't understand why you'd want unmatched disks in any kind of redundant array. Say you have 1 1TB drive and a 250GB drive you can only have up to 250GB of data be redundant. It makes no sense to me to have an unmatched array.

I believe most of the time as long as you stick with controllers from the same company you should be able to take an array from controller to controller without losing data. You're getting into a lock-in no matter what kind of redundancy you use whether it be WHS, Highpoint, Promise, Adaptec, etc. It makes little sense to quibble over this as it's really a non-issue unless you decide to change controller manufacturers sometime in the future.

And on a RAID 5 or even RAID 1 array as long as you have the proper maintenance software installed you are not going to be completely out of commission while the array is being re-built. It's performance might be decreased but it will still work. Even with a RAID 5 array the controller uses the parity data to rebuild the missing drive and can do this on-the-fly if the disk isn't finished rebuilding. Again, a non-issue.

Although, RAID does not equal backup. A lot of people have the misconception that RAID is a form of backup. It is not. RAID's purpose is to protect against drive failure and NOT data loss. You can still lose data running a RAID array, even a working array. Corruption can creep in. So even if you have a properly maintained RAID array you still need to be doing regular backups.

[stanger89]

Originally Posted by Beefcake550

While stanger89 is correct of what he writes, I wanted to add one comment that I didn't see mentioned....

If my RAID controller dies, it can be diffidult to find a suitable replacement such as not to loose any data. I have no personal experience with this, so I don't want to create FUD. This is jsut a thought in my head.

Probably depends on manufacturer, with 3ware at least, arrays can be ready by almost any controller. You can read an array built on a 7000 series card on their 8000, or 9000 series cards for example.

Originally Posted by S_M_E

That would be true with RAID too...

No it is not. Data is not written twice to a RAID array, your space is "lost" up front when you create the array. If you see 3TB available on a RAID array, you can write 3TB to it, with redundancy.

See above, same with RAID due to the cost of the array in disk space...

No. You data is only written once.

1n +1 complete drive to parity, you're trying to argue semantics. Either way RAID or WHS it's going to cost space for redundancy.

What? You lose 1/n your space. 4 drive RAID-5 array you lose 1/4 of your space to redundancy, 5 drives, 1/5th, 6 drives, 1/6th, etc.

WHS you lose 1/2 your space regardless of how many drives.

The difference is with RAID-5 you only see the usable space and you can use all of it. With WHS's pool you see all the space of all the drives, but you can't really use all of it, because everything you write is written to the filesystem twice.

Yes, they both cost space, I never said they didn't. What I said is WHS's folder duplication costs more space.

WHS's duplication is basically file-level RAID-1, mirroring. Both use 50% of the array/pool's capacity for redundancy.

More advanced RAID levels (eg 5) only use 1/n of the arrays capacity for redundancy.

Which leaves 3T on the WHS (which is what the RAID started with due to parity) and 2.5T on the array.

That would be 3.9TB vs 2.9TB.

You're right, in that scenario (3T vs 2T), if there was more data written

That's the point, RAID-5 is more efficient in it's creation of redunancy. With a 4x1TB RAID-5 array vs a 4x1TB WHS Pool, you can write 3TB to the RAID-5 array and 2 TB to the pool.

...but the money you save on a controller (especially a larger one) you can put to drives.

But you can quickly reach a point where the cost of the extra drives outweighs the cost of the controller. Say I need 6TB to start with:

RAID-5
4x1.5TB drives ($140) = $560
9550SXU-4LP = $300
Total = $860

WHS Pool
6x1.5TB drives ($140) = $840

So there ya go, for 3 drives worth of storage space, the cost is basically a tossup. But then you've got to add in the logistics of powering and installing the array. The WHS pool will pull an extra 10-20W.

I'm planning for ripping a significant number of BDs, so I'm looking at at least 8 drives (7 worth of space). Lets compare that:

RAID-5:
8x1.5TB drives ($140) = $1120
9690SA-8I = $530
Total = $1650

WHS Pool:
14x1.5TB drives ($140) = $1960
+60W * electricity rate
+1KW PSU to spin up 14 drives
+2-3 SATA controllers
+server case for 14 drives

[QUOTE]Again, semantics, I do use all of the space in you first example; I use 50G for the rip and 50G for duplication.[QUOTE]

True, I was disagreeing with your assertion that WHS is more efficient than RAID-5. Yes you see a larger capacity with a WHS pool, but you can't write as many 10GB files to the WHS pool since every byte you write is duplicated 1:1, where as with RAID-5 parity is calculated on those bytes.

What I'm not losing is space to an array only to the files I want duplicated. Additionally, while you CAN enable duplication on all of your shares, you certainly don't have to.

True, but in the OP, and many of us who write data to arrays/pools want it all redundant.

The point is a WHS Pool is equivalent (usable capacity wise) to RAID-1, or RAID-10, which are less efficient than RAID-5.

If you added another 1T drive (for a total of 4 drives) to your list; all of the data *could* be duplicated and you'd have 3T in you pool but, in that situation, you cant make a RAID 5 or mirrored array with those drives at all. With WHS you can *and* when the new 4T (or whatever) drives are available you can add 1 without have to add 3+ to make a RAID5 array.

True, which is one of the things that got me excited about WHS when I first heard about it. It's one of three options that have lots of good options. unRAID has the same benefits, as does FlexRAID. However each one of them has a significant flaw IMO:

WHS - Terribly inefficient to achieve redundancy.
unRAID - requires it's own, standalone PC, and can't be used for anything else
FlexRAID - developer dropped off the face of the earth for a while

Between the three I've about given up on using RAID in my next server, but every time I dig into one of them, I find a flaw that makes them unsuitable for my use.

If WHS used parity for redundancy instead of duplication, I'd be all over it.

I still disagree. The cost of large controllers, being forced to use matching disks, losing one or more drives to parity (for larger arrays) and as Beefcake550 rightly mentions, if your RAID controller dies you could lose your data anyway and if a drive dies it takes a LONG time to rebuild the array.

I still don't think you understand how RAID works. Yes you use 1 (or 2 for RAID-6) drives to parity with RAID-5, however of the remaining space, you can use 100% of it, data is not written twice to the visibile space on a RAID array.

This is different than a WHS pool. With a WHS pool you see all the capacity of all the drives as visible space, but everything written to a folder with duplication turned on takes up double the space.

So if you want all your data in redundant storage, RAID-5 provides a lot more usable space for a given number of drives vs a WHS pool.

And no, you don't lose your data if the controller dies.

With WHS you get more than just simple storage with the OPTION of duplication, you get backups, remote access to your shares and to your client PC's on your home network, you get built in media streaming, you can add drives that are not the same size so you can skip the expensive large controller(s), and you get easy expandability that's only limited to the ports (SATA, PATA, USB/FW all work and can be added to the pool) available on your HW.

Please understand, I'm not comparing Windows Home Server to a RAID array on another OS, I'm simply compairing WHS's implimentation of redundancy to RAID-5/RAID-6. WHS has a lot of great features, and is a great OS for a home server. I'm not denying that.

My current WHS/Sage box has 7 drives and without adding any extra controller(s) I could add 12 more drives (1 e-sata, 1 SATA, 8 USB and 2 FW) if I needed and the drives could be any size.

I wouldn't trust my data to a USB or FW drive, but that's me.

How much would it cost for a RAID controller that can handle 19 drives...

Well you'd only need 10 drives to match that capacity with a RAID controller, and such a controller would be about $500-600 or easilly $300-400 cheaper than the 9 extra drives.

If you really want a 19-drive RAID array, the controller will cost you $1100 or so, but the array would be able to hold 90% more data.

...and how many of those drives would you lose to parity?

One (two for RAID-6).

WHS is far more flexible.

Well of course, WHS is an OS, i hope an OS is more flexible than a redundancy implimentation. Again, I'm not comparing the OS to RAID, I'm comparing WHS's implimentation of redundancy to RAID's implimentation of redundancy.

Again, imo, WHS is better suited for Sage in the home than you give it credit for...

If I were buying an OS to run Sage on, it would probably be WHS. But for my 4+ TB of data (for which I want redundancy) I'd install a RAID-5 array in my WHS machine.

[Skirge01]

Originally Posted by Taddeusz

I believe most of the time as long as you stick with controllers from the same company you should be able to take an array from controller to controller without losing data. You're getting into a lock-in no matter what kind of redundancy you use whether it be WHS, Highpoint, Promise, Adaptec, etc. It makes little sense to quibble over this as it's really a non-issue unless you decide to change controller manufacturers sometime in the future.

Quibble? Hardly. I was bringing up a valid point for the OP because this is something the OP needs to consider. Don't shoot the messenger. You stated yourself that you "believe", which means you don't know for certain. I have no way of knowing if a future swap of unknown hardware will work without a hiccup, which is precisely why I said there was no guarantee.

Anyway, case in point: I went from an onboard Promise controller PDC20276 on one motherboard to a PDC20378 on another motherboard from the same manufacturer. The PDC20276 was no longer available on any newer hardware. The same (now discontinued) mobo was selling for 4 times the price I originally paid. It certainly was not just a matter of swapping in the new mobo with the PDC20378 and the array magically worked again. I don't want the OP to believe it's that simple. Due to this, if I went with hardware RAID, I was planning to buy two identical cards so that I'd have the backup if one failed. That's some ridiculous money to be spending. This is for my house, not a million dollar corporation.

Now, as far as implementing RAID, most home users who use it are (unfortunately) intending to use it either as a form of backup (which I already said it is not) or to gain perceived performance (via RAID 0 aka striping). Due to that, it's very important that people realize that 2 drives failing simultaneously, even during a rebuild, WILL result in a complete loss of all data on the array. This is why I was considering RAID6 over RAID5... until I was turned on to FlexRAID.

However, this little back-and-forth isn't really helping the OP to make a decision. If anything, it's scaring him away from RAID entirely, which is not the intention. So, to the OP, I'd again suggest you take a look at FlexRAID. It's free, BTW. If you're comfortable with Linux, take a look at unRAID, too.

[aaronlalonde]

Thanks for all the suggestions and opinions. I have just breeezed thru the latest postings sionce I got back from the parts house.

Since I just built (rebuilt) the system from scratch, I ended up buying a copy of WHS. I will also install two 80gig drives ina mirror and 2 500 gig drives as a stripe on a highpoint rocketraid 1740

I am also installing my 4 1tb WD Green drives into a drive pool for my dvd rips photos mp3's and such. The tv recordings will go on the 500 gb stripe.


I also appreciate the detail in which all have replied. Im not quite new to computers as my sage server is sitting next to my dell poweredge 2900 with perc controller. This box runs a server 2008 AD domain for my company and a few outside clients as well as hosts all my data from my online backup division.

Now for the jokes on how the guy that sells online backups didnt have backups of his own personal crap!

[S_M_E]

Originally Posted by Taddeusz

I really don't understand why you'd want unmatched disks in any kind of redundant array. Say you have 1 1TB drive and a 250GB drive you can only have up to 250GB of data be redundant. It makes no sense to me to have an unmatched array.

I believe most of the time as long as you stick with controllers from the same company you should be able to take an array from controller to controller without losing data.

WHS isn't a redundant array, it's a drive extender that uses pooled drives. With RAID a 250G drive and a 1T Drive would give you nothing. As with my previous example, if you have 2 500G and a single 1T, you could duplicate the data but you couldn't with RAID.

The key there is "most" of the time and "should" be able to, sometimes you cant.

Originally Posted by stanger89

No it is not. Data is not written twice to a RAID array, your space is "lost" up front when you create the array. If you see 3TB available on a RAID array, you can write 3TB to it, with redundancy.

No. You data is only written once.

Again semantics...

What? You lose 1/n your space. 4 drive RAID-5 array you lose 1/4 of your space to redundancy, 5 drives, 1/5th, 6 drives, 1/6th, etc.

Larger arrays are going to need more than one drive handle parity.

WHS you lose 1/2 your space regardless of how many drives.

The difference is with RAID-5 you only see the usable space and you can use all of it. With WHS's pool you see all the space of all the drives, but you can't really use all of it, because everything you write is written to the filesystem twice.

Only on duplicated shares. Duplication is on by default but it can be turned off on a per-share basis, RAID isn't as flexible.

Yes, they both cost space, I never said they didn't. What I said is WHS's folder duplication costs more space.

Not more than a mirror...

That would be 3.9TB vs 2.9TB.

Good catch, I was thinking 500G not 50G and as I said, you're right that with more data that advantage disappears.

But you can quickly reach a point where the cost of the extra drives outweighs the cost of the controller. Say I need 6TB to start with:

RAID-5
4x1.5TB drives ($140) = $560
9550SXU-4LP = $300
Total = $860

WHS Pool
6x1.5TB drives ($140) = $840

So there ya go, for 3 drives worth of storage space, the cost is basically a tossup. But then you've got to add in the logistics of powering and installing the array. The WHS pool will pull an extra 10-20W.

The advantage to WHS there is expandability. If you out grow that 6T and need more you can add more drives to WHS without having to buy 3 or 4 more drives and another controller. I'm not worried about 20W or even 200W.

I'm planning for ripping a significant number of BDs, so I'm looking at at least 8 drives (7 worth of space). Lets compare that:

RAID-5:
8x1.5TB drives ($140) = $1120
9690SA-8I = $530
Total = $1650

WHS Pool:
14x1.5TB drives ($140) = $1960
+60W * electricity rate
+1KW PSU to spin up 14 drives
+2-3 SATA controllers
+server case for 14 drives

I can run 9 SATAII drives right off my mobo, no added controllers needed and that doesn't include my 10 USB ports and 2 FW ports that can all be used for the WHS pool and even if I want to add more SATAII ports I can get an 8 port card for ~240.00. Again, when you fill up your 8 drive array, you need to buy another controller and 3+ more drives, I can just trade my smaller drives for newer larger drives and they don't have to match or I can add more. Right now I can only get 1.5T drives but what happens in X-months when we can get a 4T drive? I can just add 1 or 2 when I need more space.

True, I was disagreeing with your assertion that WHS is more efficient than RAID-5. Yes you see a larger capacity with a WHS pool, but you can't write as many 10GB files to the WHS pool since every byte you write is duplicated 1:1, where as with RAID-5 parity is calculated on those bytes.

True, but in the OP, and many of us who write data to arrays/pools want it all redundant.

The point is a WHS Pool is equivalent (usable capacity wise) to RAID-1, or RAID-10, which are less efficient than RAID-5.

Depending on the amount of data, it can and when you factor in the ease of expandability, I still think WHS is better.

True, which is one of the things that got me excited about WHS when I first heard about it. It's one of three options that have lots of good options. unRAID has the same benefits, as does FlexRAID. However each one of them has a significant flaw IMO:

WHS - Terribly inefficient to achieve redundancy.
unRAID - requires it's own, standalone PC, and can't be used for anything else
FlexRAID - developer dropped off the face of the earth for a while

Between the three I've about given up on using RAID in my next server, but every time I dig into one of them, I find a flaw that makes them unsuitable for my use.

If WHS used parity for redundancy instead of duplication, I'd be all over it.

I'm never worried about running out of space or expandability. By time I run out of space, there will be bigger drives that I can add or swap for a smaller one. Parity would be nice but it's not a deal breaker for my WHS, which is used for more than just Sage. I enable redundancy for my critical files but not every file so my total storage use is better than 50%

I still don't think you understand how RAID works.

And no, you don't lose your data if the controller dies.

I've been an IT professional for 14 years and I got my first computer in 1982, I understand RAID and I've seen RAID arrays that failed and were not recoverable short of restoring from tape. I'd say nice try, but it wasn't.

I wouldn't trust my data to a USB or FW drive, but that's me.

I don't use external drives in my pool either but it is an option that RAID can't offer. With the latest PP1, you can also use external drives to backup/archive unused/seldom used/static data.

Well you'd only need 10 drives to match that capacity with a RAID controller, and such a controller would be about $500-600 or easilly $300-400 cheaper than the 9 extra drives.

If you really want a 19-drive RAID array, the controller will cost you $1100 or so, but the array would be able to hold 90% more data.

1100+ for the controller and 19 drives. Which saves me 1100, IF I were willing to use FW/USB for the pool. I'll never need 19 drives because WHS can use any size drive so they can be updated 1 at a time regardless of size.

Well of course, WHS is an OS, i hope an OS is more flexible than a redundancy implimentation. Again, I'm not comparing the OS to RAID, I'm comparing WHS's implimentation of redundancy to RAID's implimentation of redundancy.

If I were buying an OS to run Sage on, it would probably be WHS.

Which is exactly why I said, in my first post in this thread: "I would suggest WHS as the OS instead of using a RAID array" (on XP-64) as the OP had posted.

Originally Posted by aaronlalonde

Since I just built (rebuilt) the system from scratch, I ended up buying a copy of WHS. I will also install two 80gig drives ina mirror and 2 500 gig drives as a stripe on a highpoint rocketraid 1740

I am also installing my 4 1tb WD Green drives into a drive pool for my dvd rips photos mp3's and such. The tv recordings will go on the 500 gb stripe

I think you'll find a stripe for your Sage recording folder to be a bit overkill but you can change that later if you want. What's the mirror for, the OS? Typically MS suggest you use a larger disk for the system drive but you can get away with the smaller drive since the latest patch that was released in November because that changes how the free space reporting and landing zone works. I use a 320G drive for the system drive and when I rebuild the server next time I'll use a (resized) 500G drive. Be sure to update your server before you start adding data to the shares, also, if you're going to convert the drives in your pool to 64K clusters, do it before you add much data to the shares too. I'm in the process of finishing that task now and it's a pain with a lot of data/shares...

"Now for the jokes on how the guy that sells online backups didnt have backups of his own personal crap!

You'd be surprised how many IT professionals don't do proper backups on their home networks.

[S_M_E]

Also, be aware that WHS doesn't techincally support RAID arrays although I've experimented with RAID on WHS drive pools but it caused issues with drive health reporting. If your arrays are outside of the pool, you'll have less issues. The mirrored System drive might cause issues later. I suggest reading/searching the WHS forums.

YMMV...

[aaronlalonde]

after re reading and realizing how WHS works, i ended up taking one 80gb drive off of the raid card. I only have 6 sata ports on this board, 4 1tb drives, i 80gb drive and 1 lg bluray

on the highpoint is two 500gb drives to be striped ( because i want smooth playback while recording) and the other 80 gb drive which i may remove for another project.

I will probably also end up swapping out the highpoint for something cheaper for the drive pool

[stanger89]

Originally Posted by Skirge01

Quibble? Hardly. I was bringing up a valid point for the OP because this is something the OP needs to consider. Don't shoot the messenger. You stated yourself that you "believe", which means you don't know for certain. I have no way of knowing if a future swap of unknown hardware will work without a hiccup, which is precisely why I said there was no guarantee.

As I said, 3ware does (officially, you can check the KB) support old arrays on their new controllers.

Anyway, case in point: I went from an onboard Promise controller PDC20276 on one motherboard to a PDC20378 on another motherboard from the same manufacturer. The PDC20276 was no longer available on any newer hardware. The same (now discontinued) mobo was selling for 4 times the price I originally paid. It certainly was not just a matter of swapping in the new mobo with the PDC20378 and the array magically worked again.

That's why you don't use crappy onboard RAID. Onboard RAID is a "checkmark", something to either match the competition's feature list or set your product apart. It's certainly not for robust data protection.

I don't want the OP to believe it's that simple. Due to this, if I went with hardware RAID, I was planning to buy two identical cards so that I'd have the backup if one failed. That's some ridiculous money to be spending. This is for my house, not a million dollar corporation.

There's no reason for that, just buy a good RAID card from a top company (eg 3ware).

Now, as far as implementing RAID, most home users who use it are (unfortunately) intending to use it either as a form of backup (which I already said it is not) or to gain perceived performance (via RAID 0 aka striping). Due to that, it's very important that people realize that 2 drives failing simultaneously, even during a rebuild, WILL result in a complete loss of all data on the array. This is why I was considering RAID6 over RAID5... until I was turned on to FlexRAID.

Has the FlexRAID dev returned from the abyss? There doesn't appear to have been any development since May.

[davephan]

Originally Posted by S_M_E

I can run 9 SATAII drives right off my mobo, no added controllers needed and that doesn't include my 10 USB ports and 2 FW ports that can all be used for the WHS pool and even if I want to add more SATAII ports I can get an 8 port card for ~240.00. Again, when you fill up your 8 drive array, you need to buy another controller and 3+ more drives, I can just trade my smaller drives for newer larger drives and they don't have to match or I can add more. Right now I can only get 1.5T drives but what happens in X-months when we can get a 4T drive? I can just add 1 or 2 when I need more space.

S M E,

What mobo can run 9 SATA 2 drives right of the mobo without adding a controller? Does the mobo have on board RAID?


Dave