Design for a largish Cyrus server

[Patrick Radtke]

On Dec 14, 2005, at 12:00 PM, Jure Pečar wrote:

> About iSCSI ... any expirience with it? I know throughput is good  
> enough, but what about latencies? Are they comparable with local  
> disks or fibrechannel?

I attended a "iSCSI is great" seminar last week, where a similar  
question was raised.

Their answer (people trying to sell us iSCSI gear) was something like:

Most of the latency is in the disk (order of magnitude greater then  
the iSCSI overhead).
Since iSCSI arrays are often larger then direct attached, then you  
have more disk spindles and then more throughput.

Of course if the iSCSI array and the direct attached have the same  
number of spindles then you don't get the throughput advantage.


We opted for direct attached (and using the replication code of 2.3  
to create a hot spare)  instead of iSCSI since it was significantly  
cheaper.

-Patrick




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