Web Hosting Talk : Web Hosting Main Forums : Hosting Security and Technology : What kind of SCSI Drives / Controllers do you recommend?

[AcuNett]

We're currently using a fujistu SCSI drive with Adaptec 2940U2W SCSI Controller, which doesn't seem to be working very well. Any specific controller's anyone recommends?

[Acronym BOY]

I've never been a fan of Adaptec controllers really. When performance really matters most (more than cost) I've used Mylex and Seagate Cheetahs.

[Mdot]

I like Mylex and Tekram, although using Adaptec as well, which is doing fine..


Miha.

[atjeu]

dont expect performance of scsi to beat ide unless you are going for at least 10k drives, but better yet 15k rpm scsi drives - the host controllers have a bandwidth or bus speed - data can be transferred on that bus up to the max rate -so if you have a u160 controller you can move 160MB/sec on that bus - if your drive can only do 25MB/sec it really doesnt matter that you have a 160 card - you could have an old 40MB/sec card and get the same speed - these days 7200rpm drives are just as fast as 7200rpm scsi -so you dont see "knock your socks off" performance until you get to the 15krpm scsi drives when you seek times come down to 3.5ms and so on... many people request scsi stuff because they think its automatically faster - it can be faster but its not automactically faster then ide. apples to apples its the same.

[SsZERO]

Actually, SCSI is an inherently better technology than IDE when it comes to server applications. Even if the actual drive many not be "Faster" than a comparable IDE drive, the SCSI counterpart will use much less CPU cycles, enabling it to handle a server load much better. IDE is still best suited to the desktop, single-user environment.

I would recommend what I use:

LSI MegaRAID 320-x
3 x Seagate Cheetah 10K.6 or 15K.3 in a RAID-5 config with 64KB stripe

[Mike the newbie]

Originally posted by SsZERO
Actually, SCSI is an inherently better technology than IDE when it comes to server applications. Even if the actual drive many not be "Faster" than a comparable IDE drive, the SCSI counterpart will use much less CPU cycles, enabling it to handle a server load much better. IDE is still best suited to the desktop, single-user environment.

That is not a correct statement. IDE drives using a good IDE RAID controller like the 3Ware controllers present a load on the CPU similar to a SCSI controller.

It is not the type of drive, but the type of controller that determines the CPU load.

[SsZERO]

True that a good controller will have less CPU usage than MB integrated controllers, it is still not as good as SCSI. IDE is still IDE, no matter how you slice it. I get about 2-4% CPU usage when my drives are being hammered. Never used a high-end IDE controller, but I have not found anything compelling enough for me to want to go with IDE for my server. BTW did you ever test a single IDE drive for I/O per second?

[Acronym BOY]

Originally posted by SsZERO
did you ever test a single IDE drive for I/O per second?

That's in accurate. You should test it in IO's per second per dollar. If you can buy 3 IDE drives for the price of one SCSI drive and get better performance, do it.

Yes, SCSI is a superior interface in several ways, the fact that it can tlak to more than one drive at once is usually what helps once you get into heavy I/O. If you don't need blazing performance, just quick performance, a true high level IDE RAID card (I swear by 3ware myself) would defintly be an option you shoudl look into. But if you need blazing performance and can afford it, SCSI is superior.

Pay attention what benchmarks you listen to. Sandra is not any place close to an accurate benchmark for harddrives.

[Mike the newbie]

Originally posted by SsZERO
True that a good controller will have less CPU usage than MB integrated controllers, it is still not as good as SCSI. IDE is still IDE, no matter how you slice it. I get about 2-4% CPU usage when my drives are being hammered. Never used a high-end IDE controller, but I have not found anything compelling enough for me to want to go with IDE for my server. BTW did you ever test a single IDE drive for I/O per second?

The IDE RAID controller I mentioned (3Ware) appears to the operating system as a SCSI controller, complete with tagged and queued i/o capability. For example, under FreeBSD the SCSI miniport driver is used. So the load on the CPU is the same as a SCSI controller.

For me the compelling reason to look at IDE is the price efficiency. SCSI is much more expensive per gigabyte. For example, I am in the processing of building a media storage server. I'm using three 160GB drives (7200rpm, 8MB cache) in a RAID configuration on a 3Ware controller. I will be getting 320GB of high-performance RAID 5 storage for $609 worth of drives. How much would that much storage cost if I had used SCSI drives?

So, unless you really need the high-end performance of SCSI drives, it is worth looking at the high-end IDE RAID controllers.

Note that I am not saying that IDE can be used instead of SCSI in all applications. I am saying that with the high-performance IDE RAID controllers that are available, SCSI is really needed only on very high-end servers.

And with the 10,000rpm IDE drives on the horizon, the gap is closing even further...

[SsZERO]

Originally posted by Acronym BOY
That's in accurate. You should test it in IO's per second per dollar. If you can buy 3 IDE drives for the price of one SCSI drive and get better performance, do it.

It is not "inaccurate" because you choose to include price in the equation. Pricing is not a key issue for me, and the original poster was not asking about an IDE solution nor am I. Not all people subscribe to a bargain-basement mentality when shopping for computer parts.

Yes, SCSI is a superior interface in several ways, the fact that it can tlak to more than one drive at once is usually what helps once you get into heavy I/O. If you don't need blazing performance, just quick performance, a true high level IDE RAID card (I swear by 3ware myself) would defintly be an option you shoudl look into. But if you need blazing performance and can afford it, SCSI is superior.

I have already chosen SCSI after giving brief consideration to an IDE solution. Check your MTBF numbers on those IDE drives...and seek times while you're at it.

Pay attention what benchmarks you listen to. Sandra is not any place close to an accurate benchmark for harddrives.

Benchmarks don't really tell the whole story regardless of which one you choose. Personally, I use ATTO just to gauge throughput performance...but even that is not 100% accurate. Sandra is trash for RAID benchmarks.

-= SsZERO =-

[Acronym BOY]

Originally posted by Mike the newbie
The IDE RAID controller I mentioned (3Ware) appears to the operating system as a SCSI controller, complete with tagged and queued i/o capability. For example, under FreeBSD the SCSI miniport driver is used. So the load on the CPU is the same as a SCSI controller.

And in windows a $20 promise card is listed as a SCSI adapter. So?

I can change a few files and get your drive controllers listed as a video card if I wanted to.

Originally posted by Mike the newbie
For me the compelling reason to look at IDE is the price efficiency. SCSI is much more expensive per gigabyte.

SCSI drives usually last longer too (my experience with 50 or so harddrives, half Maxtors, half WD, and 62 Seagate and Fujitsu drives). If you have to buy two IDE drives to last as long as one SCSI drive, its no longer cheaper.

Originally posted by Mike the newbie
I am in the processing of building a media storage server. I'm using three 160GB drives (7200rpm, 8MB cache) in a RAID configuration on a 3Ware controller. I will be getting 320GB of high-performance RAID 5 storage for $609 worth of drives. How much would that much storage cost if I had used SCSI drives?

I'm doing the same right now on a 3ware with 3 200GB drives to start. The fact that I can add and dynamiclly resize my array as I go means I can add storage in 200GB chunks over time.

And for me, a SCSI zealot, IDE was what I chose. It depends on what you plan on doing.

Originally posted by Mike the newbie
So, unless you really need the high-end performance of SCSI drives, it is worth looking at the high-end IDE RAID controllers.

I agree, if you don't need blazing performance, just fast performance, a 3ware with a few speedy IDE drives is probably your best bet.

If you need a 10TB array with seek times under 5ms, than yes, SCSI is what you will need.

[Acronym BOY]

Originally posted by SsZERO
It is not "inaccurate" because you choose to include price in the equation. Pricing is not a key issue for me, and the original poster was not asking about an IDE solution nor am I. Not all people subscribe to a bargain-basement mentality when shopping for computer parts.

Price is always a factor. I am not a "bargain-basement shopper" but I am a "value shopper". Sure that 30GB harddrive is only $10, but what good does it do me?

I have things I need accomplished and I have a certain budget to do it with. If I don't get it done, I get fired. Thats it in its simplest form.

Originally posted by SsZERO
I have already chosen SCSI after giving brief consideration to an IDE solution. Check your MTBF numbers on those IDE drives...and seek times while you're at it.

Well the seek time for my main 36GB boot drive as well as my spare 36GB swap drive is 3.6ms accorind to the manufacturer. How about your boot drive?

Originally posted by SsZERO
Benchmarks don't really tell the whole story regardless of which one you choose. Personally, I use ATTO just to gauge throughput performance...but even that is not 100% accurate. Sandra is trash for RAID benchmarks.

I don't even use ATTO, I use I/O Meter.

[SsZERO]

Originally posted by Mike the newbie
The IDE RAID controller I mentioned (3Ware) appears to the operating system as a SCSI controller, complete with tagged and queued i/o capability. For example, under FreeBSD the SCSI miniport driver is used. So the load on the CPU is the same as a SCSI controller.

That is the case with most RAID controllers...same deal with the HighPoint and Promise software-based controllers that are integrated onto MBs. EVen if the controller support some SCSI commands, it does not make the drives support these commands...it can only interact with the drives using the IDE command set.

For me the compelling reason to look at IDE is the price efficiency. SCSI is much more expensive per gigabyte. For example, I am in the processing of building a media storage server. I'm using three 160GB drives (7200rpm, 8MB cache) in a RAID configuration on a 3Ware controller. I will be getting 320GB of high-performance RAID 5 storage for $609 worth of drives. How much would that much storage cost if I had used SCSI drives?

If I were just looking for a place to store massive amounts of crap, I would probably go with IDE drives. I am referring to an environment where the drives will be slammed with I/Os 24/7 without a break. In such a scenario, using IDE is asking for downtime. For file storage server which will not be serving up web pages or doing any kind of database work, IDE is fine.

So, unless you really need the high-end performance of SCSI drives, it is worth looking at the high-end IDE RAID controllers.

Note that I am not saying that IDE can be used instead of SCSI in all applications. I am saying that with the high-performance IDE RAID controllers that are available, SCSI is really needed only on very high-end servers.

And with the 10,000rpm IDE drives on the horizon, the gap is closing even further...

I don't think SCSI should be relegated to "only very high end". It is more affordable than before, even if it is still more expensive than IDE. The question you need to ask is: "Will downtime cost me more than the money I saved by using an IDE setup instead of SCSI?"

There are a few 10K RPM SATA drives slated for release soon, but we already have 15K scsi drives...and their prices are getting lower and lower. On top of that, the U320 interface is more than double the 150MB/s offered by SATA and nearly triple that of ATA-133.

-= SsZERO =-

[Acronym BOY]

Originally posted by SsZERO
There are a few 10K RPM SATA drives slated for release soon, but we already have 15K scsi drives...and their prices are getting lower and lower. On top of that, the U320 interface is more than double the 150MB/s offered by SATA and nearly triple that of ATA-133.

SATA is a gimick. And if you want to talk about interface limitations...

Interface limitations are always ahead of what a drive can actually push though. We don't have drives that can saturate a 133MB/s channel, yet all of a sudden we need SATA?

And as for SCSI, there is still u640 (soon) and the current FC offering of 2 GB/s loops (plus you can always go for power of fiber as well).

[SsZERO]

Originally posted by Acronym BOY
Price is always a factor. I am not a "bargain-basement shopper" but I am a "value shopper". Sure that 30GB harddrive is only $10, but what good does it do me?

Nothing wrong with value shopping...but I am speaking for myself. I chose Seagate Cheetah 10K.6 @ 36 GB because:

- 6th Generation technology
- Sub 4ms seeks
- 1.2 million hour MTBF (SLIGHTLY more reliable than IDE)
- Perfect for supporting multiple database-driven sites with ease.

I have things I need accomplished and I have a certain budget to do it with. If I don't get it done, I get fired. Thats it in its simplest form.

True, if you are working for someone else. I make all the choices, and I follow the saying, "Do it right the first time so you never have to do it again." Downtime would cost me much more than I would ever save with an IDE solution...so I would consider a lower-end SCSI solution before IDE if my budget was limited.

Well the seek time for my main 36GB boot drive as well as my spare 36GB swap drive is 3.6ms accorind to the manufacturer. How about your boot drive?

About the same. Check seagate's site for 10K.6 Cheetah drives.

I don't even use ATTO, I use I/O Meter.

Yeah, IO Meter is pretty good...at least it tries to simulate a server environment moreso than any others. But ATTO gives reasonably accurate results and only takes a few minutes to complete.

-= SsZERO =-