SSD vs SAS in server

[ncalipari]

Hello guys,

I'm building a database server, the current (unchangeable) specs are:

Intel® Xeon E3-1275

1 x NVIDIA Tesla C1060 4GB

16 GB DDR3 RAM ECC

4 port hardware raid

Linux MD RAID 10 (with 2 disks) or Raid 1 (need to benchmark which is better).


I have to choose the memory subsystem:

2 x OCZ VERTEX 3 SATA III 120 GB

http://www.ocztechnology.com/ocz-vertex-3-sata-iii-2-5-ssd.html

2 x Corsair Force 120 GB

http://www.newegg.com/Product/Product.aspx?Item=N82E16820233125
Cheetah 15K.7 SAS 6-Gb/s 300-GB

http://www.seagate.com/ww/v/index.j...toid=6664470bd8cc1210VgnVCM1000001a48090aRCRD


There are also 2 SATA disks for massive storage. My questions are:

1) SAS or SSD?

2) Which SSD is more reliable?

3) Is it worthwile to have 2 SSD, and change the SATA disks with 2 SAS?

thanx

 

[ThatsABigOne]

I can answer # 2 for you and Corsair Force will be much more reliable, despite it using the same controller as Vertex 3. Corsair is a reputable company that stands behind their products, meaning you will get the newest firmware that does not botch your SSD.

 

[Coup27]

I can answer # 2 for you and Corsair Force will be much more reliable, despite it using the same controller as Vertex 3. Corsair is a reputable company that stands behind their products, meaning you will get the newest firmware that does not botch your SSD.

As much as I am not OCZ's biggest fan myself, comments like this really do not help the situation.

Both OCZ and Corsair release drives using the same controller with the same firmware. The rest of the drive is NAND and other stuff which are all sourced from the same places. If your system rejects a Vertex 3 (whole other discussion), then it'll reject a Corsair Force 3.

OP - You do realise that you are comparing two different generations of Sandforce based drive? Depending on how hard the DB server will be writing to the disks depends on what you should buy. Standard MLC flash is not used in heavy workload servers because it won't last that long. Intel have released the SSD 710 which uses high endurance MLC flash which is designed for this purpose, but it's expensive. If the DB server will be doing loads and loads of writes, then you'll be better off with the HDD.

 

[tomt4535]

Do you have a SAS controller in it? Sata drives can be connected to a SAS controller, but not the other way around. I agree with Coup27, I would not put a desktop class SSD into a server, especially a DB server. Use an enterprise class SSD or the SAS drives.

 

[ncalipari]

OP - You do realise that you are comparing two different generations of Sandforce based drive? Depending on how hard the DB server will be writing to the disks depends on what you should buy.

I realized that they are from different generation, but I couldn'f find a review that compared both.

What would you choose in a high random read-to-write scenario?

Standard MLC flash is not used in heavy workload servers because it won't last that long. Intel have released the SSD 710 which uses high endurance MLC flash which is designed for this purpose, but it's expensive. If the DB server will be doing loads and loads of writes, then you'll be better off with the HDD.

The SSDs are paid by the month. As soon as they degrades, they are switched, without any cost.

Do you have a SAS controller in it?

Yep, a high class one.

Sata drives can be connected to a SAS controller, but not the other way around. I agree with Coup27, I would not put a desktop class SSD into a server, especially a DB server. Use an enterprise class SSD or the SAS drives.

Consider that the data will be replicated across two SSD, and again on the SAS/SATA disks, and again in a hourly backup. I think that the likelyhood of data loss is very small.... what do you think?

 

[LokutusofBorg]

Optimal builds for database servers depend a lot on the RDBMS you'll be running, the actual load that will be put on the server, the number and size of databases, etc. But if you really only have a four port RAID card, meaning you can only put four drives in your server, then you're fairly limited.

The most performant RAID is RAID10, but you need four drives minimum to do it. I would not recommend RAID5 at all. And RAID1 has almost no performance enhancement.

Are the two SATA drives you mention going to be taking up two ports on the RAID card? If so, I would recommend you drop the SATA drives and go with 4 SAS drives in RAID10 if you really do need the space you were going to get from the SATA drives. If you don't really need that "massive space", then you can go with 4 SSD drives in RAID10.

Along the lines of "don't use consumer-grade stuff in a server" I would recommend you at least go with Intel 320 SSDs if you go the SSD route.

You might want to read through this article to see if it gives you any insight.

 

[Emulex]

i've found that RE4 drives in raid-10 (or raid-1 but both drives read for double speed) 2TB for LOG with SSD for the main DB (raid-1) and another SSD for TMPDB (if you don't have alot of ram and force tmpdb to ram) works GREAT.

remember that the intel 710 is an intel 320 (Same controller) with cherry picked nand - they drop the iops by 20-50x slower and use like 1/2 of the nand for overprovision to give you 20-50x more lifespan. The same controller (x25-m/320) is used just different firmware. so if you were to use only 50% of the intel 320 and could hack the 710 firmware onto the 320 you'd get pretty good lifespan but the IOPS go WAY down on read.

Anyways - RE4 2TB drives for log in raid-1/10 work great - SSD for main database in raid-1 and your choice on tmpdb - i'd prefer to just use a ton of ram since its cheap these days.

LSI cachecade is a great alternative as well. But honestly 72gb or 144gb of ram works very well too

RAM 1st, decent raid controller (check out the adaptec and lsi hybrid caching solution, it works on ESXi/hyper-v [lsi cachecade 2.0]) and RE4(enterprise ssd, or enterprise velociraptors) works awesome.

SAS 900gb drives are expensive and only 10K RPM @ 2.5" (3.5" are 15K) but we're talking nearly a grand for 15K drives.

With compression on SQL SERVER 2012/2008R2 you can really stretch your ram since the buffers are compressed as well.

Given the issue with drive availability and the artificial price hikes - and low ram prices i'd focus on a metric ton of ram - RE4's in raid-10 for tmpdb/log and SSD for core db storage with massive overprovisioning you can rock that.

Honestly though if you can afford to use the newest 2012 - it has automatic failover/always on you can build cheap boxens. AMD's are really good for their cheapness and ton of ram slots. Until xeon's with quad channel ram come out that is definite advantage with enterprise edition of sql server - you can really compress your tables and use the cheaper ram that the AMD's take care of but beware SQL SERVER 2012 is going to charge PER core(!!) so that AMD 8-core that is as slow as a 4-core intel will cost you tons in licensing.

 

[exdeath]

SSD. If you want slow instead just cut to the chase and go reel to reel.

 

[pitz]

WTF is half that junk? OCZ in a server? Nvidia? Seriously... Go to the Dell (HP, etc.) catalogue, find something that uses conservative hardware, and order it. You're wasting a lot of time trying to configure this yourself, and, quite frankly, exposing yourself to a lot of headaches which will have to be resolved, on your dime. What's the price of this server compared to the data that will be on it?

If this is for a devel/game machine, fine, but I hope you're not going to try to run a business on this stuff...

 

[Massive Overkill]

LSI cachecade is a great alternative as well. But honestly 72gb or 144gb of ram works very well too

This. SSD as cache............SSD goes bad, simply replace it, no having to restore from backups. Use less-expensive, higher-capacity disks to store data and have sufficient SSD cache \ RAM to satisfy IOPS requirements.

Because SSD is cache and not storage, you don't need to use expensive SLC, unless you're choosing it for performance reasons.

Database compression is nice.......wish MS offered it on non-enterprise versions of SQL.

 

[Cerb]

If this is for a devel/game machine, fine, but I hope you're not going to try to run a business on this stuff...

How would a server with IGP be fine for a gaming machine?
Conversely, how is a server CPU, in a server mobo, with ECC RAM, a SAS controller, and server vector processing AIB, not good for running business applications?

You're wasting a lot of time trying to configure this yourself, and, quite frankly, exposing yourself to a lot of headaches which will have to be resolved, on your dime.

That is the case anyway. Buying a Dell does not avoid that. IT services salespeople just want managers to think so, because it is lucrative for their employers, up until the point where your boss finally gets the clue bat.

Dell/HP/IBM/etc. can not prevent nor quickly solve your problems. They can send a part, if the problem is obviously failed hardware they warrantied; or a [contracted out] technician, who doesn't have a clue what you are doing before he gets on site, and that you want to watch like a mama bear, to make damn sure he doesn't screw up anything while diagnosing some obvious problem.

In the case of a part, you still have to wait, so you would be no better off than if you had planned for certain types of failure in the first place, which would require that you buy spares; or if you just ordered it with fast shipping.

If the OP has a high performance DB application that is going to kill any hardware thrown at it, that's not nearly the same as some random web app or email server. Configuration details matter, and I know just enough to know that I don't know nearly enough to help the OP on the SSDs.

 

[Denithor]

I would lean toward the SSD option and point toward Crucial M4 or Samsung 830 drives as viable alternatives to the Vertex/Force drives.

 

[ncalipari]

Optimal builds for database servers depend a lot on the RDBMS you'll be running, the actual load that will be put on the server, the number and size of databases, etc. But if you really only have a four port RAID card, meaning you can only put four drives in your server, then you're fairly limited.

The most performant RAID is RAID10, but you need four drives minimum to do it. I would not recommend RAID5 at all. And RAID1 has almost no performance enhancement.

Are the two SATA drives you mention going to be taking up two ports on the RAID card? If so, I would recommend you drop the SATA drives and go with 4 SAS drives in RAID10 if you really do need the space you were going to get from the SATA drives. If you don't really need that "massive space", then you can go with 4 SSD drives in RAID10.

Along the lines of "don't use consumer-grade stuff in a server" I would recommend you at least go with Intel 320 SSDs if you go the SSD route.

You might want to read through this article to see if it gives you any insight.

great insight

 

[jstern01]

Optimal builds for database servers depend a lot on the RDBMS you'll be running, the actual load that will be put on the server, the number and size of databases, etc. But if you really only have a four port RAID card, meaning you can only put four drives in your server, then you're fairly limited.

The most performant RAID is RAID10, but you need four drives minimum to do it. I would not recommend RAID5 at all. And RAID1 has almost no performance enhancement.

Are the two SATA drives you mention going to be taking up two ports on the RAID card? If so, I would recommend you drop the SATA drives and go with 4 SAS drives in RAID10 if you really do need the space you were going to get from the SATA drives. If you don't really need that "massive space", then you can go with 4 SSD drives in RAID10.

Along the lines of "don't use consumer-grade stuff in a server" I would recommend you at least go with Intel 320 SSDs if you go the SSD route.

You might want to read through this article to see if it gives you any insight.

From the looks of it, RDBMS will be a linux flavor. I would recommend that you use the SSD's for rollback/redo/undo/temp work, and the HD's configure as raid 10 for the database, indexes and such.

 

[atl]

RAM RAM RAM!
1. Get rid of E3-1275. It is named "Xeon", but is actually Sandy 2600 (without the K). It is pure desktop CPU.
2. Get dual socket G34 Mobo. One with all (16) DIMM slots on it. Like H8DGi. ~$450.
3. Get 16 cheap 4GB DIMMs for ~$300.
4. Fill it with 2 cheap Opterons. 6128 for ~$220 (440) will work.
5. Put 4 x 500 WD Re4 - 4 x $70 from http://www.provantage.com/supermicro...x~7SUP92EM.htm.

Total for ~$1500.

This with the cheaper HDDs will own every possible 16GB RAM setup, no matter what disks, SSD, CPU, Nitros or tuning have on it.

If you can spare $1000 more, go for H8QDGi board with 32 DIMMS (128G) RAM and 4 x Opteron 6128.
Don't buy 8GB DIMMs, they are insane priced now.