Database Server Build

[Aquinus]

Anandtech has a review on RAID and different drives in RAID, including SATA, SAS, and SSD drives. I really think SAS is the better option. The SSD really only helps on random reads and when you're joining on large tables you're going to be doing very large sequential reads. Also keep in mind TRIM doesn't get passed on SSD raids so you're write speed will suffer over time and on databases that are update/insert/delete heavy you may run into issues. So the heavier the read bandwidth, I would go SSD, the heavier the write, go SAS.

http://www.anandtech.com/show/2739/10

 

[theeldest]

Anandtech has a review on RAID and different drives in RAID, including SATA, SAS, and SSD drives. I really think SAS is the better option. The SSD really only helps on random reads and when you're joining on large tables you're going to be doing very large sequential reads. Also keep in mind TRIM doesn't get passed on SSD raids so you're write speed will suffer over time and on databases that are update/insert/delete heavy you may run into issues. So the heavier the read bandwidth, I would go SSD, the heavier the write, go SAS.

http://www.anandtech.com/show/2739/10

Hey Aquinus,

Did you check out the review I posted by StorageReview?

They post numbers for an Intel 520 in a 'steady state' environment. IE, worst case scenario when Trim and Garbage Collection don't have time to run.

The numbers that a single SSD is able to provide are quite a bit higher than SAS drives. I ran the exact same tests on a 12 disk array of 15k SAS drives and the array was slaughtered by the SSD.

The SSD is going to give better performanc--hands down--even if Trim and Garbage Collection don't have a chance to run in the background.


Also,
On the review you linked, the very next page gives "Real World Database Results". It shows that a single SSD as the data disk provides 66% higher performance than 8 SAS drives.

... Did you even read the article you posted?

 

[Aquinus]

Also,
On the review you linked, the very next page gives "Real World Database Results". It shows that a single SSD as the data disk provides 66% higher performance than 8 SAS drives.

... Did you even read the article you posted?

Real world databases aren't going to be doing a ton of random reads and writes. When you're using large tables and joining on large sets of data you're looking at sequential reads more than anything else. Also my concern isn't with the speed of the SAS drives vs SSD, my concern is the reliability of the SSD which becomes a concern in write-heavy scenarios.

Yes, I did read it and it does say SSD is faster for many things (sequential reads/writes are another story), but in mission critical applications you don't want to worry about drives failing and I suspect that a SAS drive will last longer than an SSD while providing more storage.

Kreij: If you went with SSDs, were you planning on going with SLC or some incredibly over-provisioned MLC?

 

[theeldest]

Also my concern isn't with the speed of the SAS drives vs SSD, my concern is the reliability of the SSD which becomes a concern in write-heavy scenarios.

Check this review I posted earlier.

Regarding degradation: here's another good review: http://www.storagereview.com/ssd_performance_review_270tb_written

They wrote 270 TERABYTES to an SSD and compared performance before and after.

Also, a single Intel 520 will give sequential writes around 300 - 500 MB/s . You'll need 4 - 12 SAS drives to give the same performance depending on RAID type. That's a significant difference in cost.

It just makes more sense to use SSDs and replace as necessary. The cost will be lower, they've proven to be reliable under heavy write conditions, and the performance will be higher, even in sequential loads.


And finally, this 'Planned Obsolescence' gives Kreij a little more job security ;-)

 

[Kreij]

Kreij: If you went with SSDs, were you planning on going with SLC or some incredibly over-provisioned MLC?

Neither. The Mushkins Enhanced Chronos' were only $102 for 120GB, so I'm winging it.
I just glanced at the specs and thought, "let's see how it goes."
If it doesn't work out I'll just pick up another pair of 150GB raptors and use those.

And finally, this 'Planned Obsolescence' gives Kreij a little more job security ;-)

My title is IT Manager. It's a little misleading as I am the whole IT department.
I don't worry about job security, never have, never will. There is always work for experienced network people, even moreso if you can write code.

 

[suraswami]

If the database is set right rather designed right with proper indexes then you can even run it in a VM.

I use SQL Server and been a while since touched a Oracle DB server. my lowest user (10 to 15) base reporting server with nightly updates is running a 1U IBM with a xeon 2.33 ghz quad and 12gb ram and 2 x 1TB WD black enterprise 7200 rpm in RAID 1 (yes OS and everything on one set, bad but that is what I had as budget and option). The DB size is about 200GB and reporting tables are in the million row range, nightly or monthly about 80 to 90 million rows gets scrubbed. I designed the tables and indexes in the most optimum way and never the reports seem slowing down even with couple of graphs and charts to render using SSRS.

So I would imagine the 7200 drives would give decent performance if DB is configured right, but the SSDs would do better if it can handle garbage and TRIM properly.

my 2 cents.

 

[Kreij]

I agree on the importance of a good DB design.
In this case, though, it's a 3rd part app and I have no control over how the tables, views, packages, etc. are/were written.

 

[Mindweaver]

Neither. The Mushkins Enhanced Chronos' were only $102 for 120GB, so I'm winging it.
I just glanced at the specs and thought, "let's see how it goes."
If it doesn't work out I'll just pick up another pair of 150GB raptors and use those.

I've been eyeing those Mushkins.. and for 102 for 120gb the pot just got sweeter... hehehe I rma'ed a few 150gb raptor a few months ago. The new ones I got back are totally redesigned. They are 2.5 notebook drives incased in a 3.5 heatsink. they look cool and so far they have performed well... But if you ask me I would get 2x of those SSD's and put them in RAID 1 or get 3x and go RAID 1e. I'm using 4x of those raptors in RAID 5 w/ a Hardware RAID controller and read and write is still lower than the SSD's in RAID 1.

My title is IT Manager. It's a little misleading as I am the whole IT department.
I don't worry about job security, never have, never will. There is always work for experienced network people, even moreso if you can write code.

You're in the same boat as me... lol about 6 years ago I had about 15 people that I managed... but I left that company.. tired of traveling.. leaving Monday and not coming home until Friday. So, now I manage a few different smaller companies, but get to come home every night! The traveling was fun when I was younger.. hehehe Suck getting old..lol

 

[Kreij]

I was pondering going with 4x 60GB SSDs and putting them in RAID0+1, but I really don't think I need the speed boost.

I know what you mean MW. I work to live, I don't live to work ... and there is a lot to be said about coming back to your own home after work.

 

[Mindweaver]

I was pondering going with 4x 60GB SSDs and putting them in RAID0+1, but I really don't think I need the speed boost.

Yea RAID0+1 would be nice. I would be hard pressed to get the 60gb over the 120gb seeing how the 60gb's are still around 80 bucks and the 120gb's just drop to around 100 bucks. Double the space for quarter of the price. Also, I noticed the 640 RAID controller card you are looking at 1x to 3x ports are rated 6gb and the 4x is rated at 5gb. You shouldn't see a big difference, I just wanted to make sure you seen that buddy.

I know what you mean MW. I work to live, I don't live to work ... and there is a lot to be said about coming back to your own home after work.

You said it Brotha!

 

[yogurt_21]

I agree on the importance of a good DB design.
In this case, though, it's a 3rd part app and I have no control over how the tables, views, packages, etc. are/were written.

hence the larger than needed hardware specs I'd imagine. Somthing we've been having to do at my company since I've been here, throw bigger hardware at the issue since the programming isn't getting any better. lol