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hudan
1 Copper

Maximum IOs per sec for the FA port and LUN utilization

Hi All,

Maximum IOs per sec for the FA port and LUN utilization? Because customer plan would raise the utilization .... Server, whereas the current utilization of the FA port used ... Server was quite high.

1.Do you know the Maximum IOs per sec for the FA port and LUN utilization?

2.There are several pairs of ports that IOs per secnya differ greatly among 8E and 9E on the Site X , 7E and 10E on Site Y, they question what is the cause of this?

Thanks,

Hudan

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9 Replies
Quincy561
4 Tellurium

Re: Maximum IOs per sec for the FA port and LUN utilization

The maximum IO rate for a FA CPU depends on the IO type (the FA can service 4 types, overwrite, new write, read hit and read miss) and the IO size.  A single Symm volume can deliver about 1/4 of the total performance of the FA CPU. 

If the workload is different between site Y and site X, it probably is different.

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hudan
1 Copper

Re: Maximum IOs per sec for the FA port and LUN utilization

what do you mean IO type and IO Size?

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Quincy561
4 Tellurium

Re: Maximum IOs per sec for the FA port and LUN utilization

IO types the FA can service are overwrite (write to slot already write pending), new write (write to slot not WP), read hit (read of data that is in cache) and read miss (read of dat that is not in cache)

All four of those IO types have different performance maximums on the FA CPU.

IO size of 4k can do more IOs/sec on the FA CPU than a 1MB IO size.

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Lazarmartin
1 Copper

Re: Maximum IOs per sec for the FA port and LUN utilization

Max throughput of a storage FA/sec ?

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Quincy561
4 Tellurium

Re: Maximum IOs per sec for the FA port and LUN utilization

Max throughput of a storage FA/sec ?  ?? 

I think I answered that.  It depends.  There is not one answer, unless you want the absolute maximum, which is for a 100% read hit workload with 512 byte IOs.

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hudan
1 Copper

Re: Maximum IOs per sec for the FA port and LUN utilization

1.whether it is same FA CPU and FA Port?

2.where can i know that the FA port is using IO type (overwrite,new write, read hit or read miss) ?

3.where can i konw the IO size?

4. Can you explain more about this -> "A single Symm volume can deliver about 1/4 of the total performance of the FA CPU", i don't understand

5. whether it is same IO size and block devices size?

please for your explain

Thanks,

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Quincy561
4 Tellurium

Re: Maximum IOs per sec for the FA port and LUN utilization

1) There are two ports on one FA CPU.  The CPU has a limit of how many IOPs it can do.  1 port or both ports do the same number of total IOPs.

2) You can look at the Symm statistics, however the overwrite and new writes are not easy to determine.  You could assume that 30% of the writes are overwrites.

3) You can see IO size from host tools such as perfmon, or sar or iostat, or from Symm statistics from ECC or SPA

4) A single volume can deliver only about 1/4 of what the FA CPU can do, so you need at least 4 volumes to get the full performance of a FA CPU.

5) I don't understand this question.

hudan
1 Copper

Re: Maximum IOs per sec for the FA port and LUN utilization

for number 4, do you mean in storage group, minimal must have 4 volume?

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Quincy561
4 Tellurium

Re: Maximum IOs per sec for the FA port and LUN utilization

Could be a storage group, or just a meta volume or a host stripe set.  You don't have to use at least 4 Symm volumes for any workload, just if you were trying to get the maximum possible IOs/sec from a FA CPU.

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