CX 3x performance

[gsavy]

hello

We have a brand new san with 2 CX320 with 4 Gbps switches.

Yes it's fast, really fast compare to DAS.

But how can we be sure it is as fast as it should be ?

Today we created a mirror between the 2 CX, and creating a 800 GB mirror lasted 4h , I found it slow.
source and target are on Raid5 on 5 disks 300 GB 15k


I checked on the switches with 'portperfshow' command, and the average speed during synchronization was around 80m

Do you have tools to measure speed.
How long do you need to synchronize a x GB mirror
Thanks for your help

 

[mrdenny]

The amount of time needed to transfer the data will vary depending on the amount of load on each RAID Group. Also what priority did you give the mirror operation?

Denny
MCSA (2003) / MCDBA (SQL 2000)
MCTS (SQL 2005 / Microsoft Windows SharePoint Services 3.0: Configuration / Microsoft Office SharePoint Server 2007: Configuration)
MCITP Database Administrator (SQL 2005) / Database Developer (SQL 2005)

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[gsavy]

I gave maximum priority and there was nothing else working on the CX320 as we are setting it up, so no production yet.

That's why I think it is quite slow ?

 

[mrdenny]

Do you have Analyzer setup on this unit? If so what does the disk performance look like on the LUN and RAID Group that you are writing to? How about the one that you are reading from?

Denny
MCSA (2003) / MCDBA (SQL 2000)
MCTS (SQL 2005 / Microsoft Windows SharePoint Services 3.0: Configuration / Microsoft Office SharePoint Server 2007: Configuration)
MCITP Database Administrator (SQL 2005) / Database Developer (SQL 2005)

My Blog

 

[gsavy]

no unfortunatly we didn't know about Analyser and we didn't buy it.

 

[mrdenny]

I believe that you can access this from the CLI. I don't know the commands however. You should be able to get the commands from the docs up on powerlink.

Denny
MCSA (2003) / MCDBA (SQL 2000)
MCTS (SQL 2005 / Microsoft Windows SharePoint Services 3.0: Configuration / Microsoft Office SharePoint Server 2007: Configuration)
MCITP Database Administrator (SQL 2005) / Database Developer (SQL 2005)

My Blog

 

[morg2k2]

Hi,

Just to understand, the disks are:

-Fiber
- SCSI
- SATA (i dont believe they are sata since you´ve stated 15k rpm)

because scsi are much slower compared to fiber disks.

 

[gsavy]

hello all
thanks for your answer

so I found Analyzer on CLI, but as we are not licenced, we can ony get NAZ file instead of NAR file. NAZ files are NAR file but encrypted !
With EMC you have to pay for evrything... !

Yes disk have FC 15k 4GB, with also have SATA 4GB

once again it's a good marketing speech: "yes you can mix drives FC and SATA, so you can have low cost drives", but in fact if you put SATA drives, you have to put 4 GB Sata drives otherwhise you will affect performances on FC drives, in that case price of SATA drives is nearly the same as FC drives !!!

 

[NickFerrar]

Yeah once you start buying into EMC get used to spending lots of money for the extras I thought the SATA drives were 3GB and didn't affect the back-end bus bandwidth as they pretend to be 4GB? Snapshots between FC and SATA will slow the FC LUN down though.

 

[comtec17]

How much cache do you have setup on the Array and how are the 2 arrays connected?

A single 15k RPM spindle only operates at around 12MB/s.

How are your mirrors setup? I am looking to see if you have fracture logs or write intent turned on.

If async, what type of disks are you using for the Reserve LUN pool?