RE4 vs VelociRaptor for SQL Server and Hyper-V

scandinator

scandinator

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Hi there. I have a problem with the disk selection. Which discs would you choose? Thinking the Western Digital RE4 2TB 64MB cache and 1TB Western Digital Velociraptor 64 megabytes cache. Discs will be 8 in a raid that will be used for both SQL Server and Hyper-V with 4 VPS.
Which would you choose?
 
How busy is the database? Is it a busy website database or a accounting software database? number of users? Do you need the 16TB raw, or would 8TB do? Do you need to plan for future capacity?

All of the disks are pretty fast, but the velociraptors would get you more IOPS, and more IOPS means faster database queries, allows more simultaneous vm guests.
 
These benchmarks are the 2TB RE4 against the 600GB Raptor

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My database does not very much use. Do not need special performance of transactions or so.
I want to have it as a test and development databases.
Well there is this some database that have 10 gigabytes maybe one db will have 100 gigabytes.
But I do worry hyper-v. I respect the maximum reliability ties VPS.
This is a vps which is located on metatrader trading on the stock exchange and there slots which open automatically store.

I need to intelligently redistribute the VPS RAID1, RAID1 for backup, RAID 1 for database. RAID1 on the system.
 
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Also on 147, 300 and 600GB versions. They are pretty widely on supported according to many HCL's I've read on many RAID cards (adaptec, LSI..)

I'd say if you don't have need of the capacity of the RE4, I'd get the VR. They are a noticible step up from 7200rpm drives and cheaper than SSD.

If you know your database sizes are going to be only that big, you might consider a pair of SSD's mirrored in RAID1. It will be magnitudes faster than mechanical drives, even in R1.

You can setup tiered storage for different purposes pretty easily if you have good control of your environment and are organized.
 
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Do you have a way to determine IOPS? Faster RPM = more IOPS, but it's multiplied by # of disks. Becomes fairly easy to determine if you need more RPM''s or not.

Good IOPS calculation figures based on per spindle and spindle speed (there are other variables, but this is the general figure used by most every storage vendor)

15k drives = 200 IOPS each
10k drives = 150 IOPS each
7.2k drives = 100 IOPS each

So just run some math. 8 disks (assuming no hotspares) would be 800 IOPS for 7200rpm or 1200 IOPS for 10k RPM.

Queue Length is also important, since that's a factor of spindles too.
 
Greetings

Ideally for max IOPS then SSD is the way to go but at a buck a GB this is very expensive, also if there is a lot of writes you may wear out consumer SSD's quickly and also enterprise SSD's are even more expensive.

Have you considered enterprise SAS instead of SATA? If you get a SAS raid controller you can run both SAS and SATA drives on it.

Something like an M1015 card would do the job and you can get a new one for $217.00 or a second hand one for $94.00

SAS drives run at 7200, 10K and even 15K rpm so this will be a middle ground between SSD's and consumer SATA drives.

There's a wide variety to pick from in the 15K speed depending on the size you require and your budget e.g.

36Gb for $39.00,72 Gb for $62.00,146GB for $80.00,
300GB for $135.00,450GB for $144.00,600GB for $240.00

These are prices for brand new ones so second hand ones would be a lot cheaper. The 450GB ones probably are the best value out of this selection.

If you are not sure about what performance you may need then with the 8 port SAS card you could have a mix of drives, most likely you would want Raid1 mirrors for redundancy so if you were going to populate the raid card with 8 drives you could install the following 4 groups of mirrors ranging from (most performance/least storage size) down to (least performance/maximum storage size) and all of these would support TLER.

(a) a pair of 15K rpm SAS drives

(b) a pair of 10K rpm raptors

(c) a pair of 7200 rpm RE4's

(d) a pair of 5400?/5900? rpm WD NAS Red's

and then just migrate your apps up or down depending on their speed/size requirements

Food for thought

Cheers
 
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HDClown said:
Do you have a way to determine IOPS? Faster RPM = more IOPS, but it's multiplied by # of disks. Becomes fairly easy to determine if you need more RPM''s or not.

Good IOPS calculation figures based on per spindle and spindle speed (there are other variables, but this is the general figure used by most every storage vendor)

15k drives = 200 IOPS each
10k drives = 150 IOPS each
7.2k drives = 100 IOPS each

So just run some math. 8 disks (assuming no hotspares) would be 800 IOPS for 7200rpm or 1200 IOPS for 10k RPM.

Queue Length is also important, since that's a factor of spindles too.
Click to expand...

That's raw iops, don't forget about write penalties depending on raid level used. Raid 1/10 has a penalty of 2, raid 5 has a penalty of 4, raid 6 has a penalty of 6.
 
Eickst said:
That's raw iops, don't forget about write penalties depending on raid level used. Raid 1/10 has a penalty of 2, raid 5 has a penalty of 4, raid 6 has a penalty of 6.
Click to expand...

Do oyu have any resources wiht more detailed info on this? Would love to read more into the specifics.

Thanks
 
For the record, I used to rely on 15k SAS drives in RAID 5, and the SSD just dusts them for this stuff.
 
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