performance

[peterve]

quick question : what should be faster ?

1. front end server with FC card, connected to back-end SAN, using a 2Gbit connection

or

2. frond end server with internal disks, using U320 SCSI adapter, and 15000 rpm disks

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[comtec17]

# 1 for the mear fact it the SAN disk will have 2GB of channel speed vs 320MB for the SCSI drive. Fibre Channel Drives will always out perform SCSI.

Now, this all depends too on how you setup the spindles

 

[peterve]

But isn't the effective throughput on 2Gbit FC = 180Mb/sec ?
(which would be lower than 300Mb/sec on U320) ?

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How can I believe in God when just last week I got my tongue caught in the roller of an electric typewriter?
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[fraxx]

Define "fast" in your context. How do you measure the speed, in what unit?

 

[peterve]

I want to compare the speed of a server with local disks (U320 SCSI) vs a basic SAN with a 2Gbit connection

I just want to know what will be faster in real life, not in theory...



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How can I believe in God when just last week I got my tongue caught in the roller of an electric typewriter?
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[Chacalinc]

I just want to know what will be faster in real life, not in theory...

In the real life there are different technologies, not just SCSI/FC bus... what is yor SAN Storage? I can tell you that if you use a storage array named EMC Clariion, Symmetrix, Hitachi (HDS) Ligthning or Thunder, IBM FastT, etc. with 2 Gbps FC you will get lot better performance than using internal U320 SCSI disks, why? technology: more cache, better storage processors, internal switching, dual loops, etc.

So, do you want to compare FC v/s SCSI? yes, 320 is greater than 200, but SAN v/s internal SCSI? see the technology.

Cheers.

Chacal, Inc.

 

[fraxx]

I'll just make it short for now; measuring speed in this context using MB/s is wrong in more than 90% of the real-world scenarios.

 

[peterve]

ok - thanks

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How can I believe in God when just last week I got my tongue caught in the roller of an electric typewriter?
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[Breslau]

technically speaking, if you're running FC storage, you're running scsi. FC is just a transport protocol.

if your i/o needs are random and you want speed and scalability, i would not consider a direct attached solution.