[wplug] Thoughts & Considerations for email server

[Michael Skowvron]

Kevin Squire wrote:
> ALL THE RAID 5 COMMENTS -
>   It is a hardware setup, HP Smart Array e200/128 BBWC Controller

There is an inconsistency. This is a PCI Express card but the 
specifications for the Proliant system you list indicate that it comes 
with a PCI-X RAID card. Either this is not the card, the specs are out 
of date, or you are specifically choosing this card. The system has both 
PCI-X and PCIe slots.




HP Describes the card as:

    "HP's first entry level PCI Express (PCIe) Serial Attached SCSI 
(SAS) RAID controller. The full size card has 8 ports and utilizes 
DDR1-266 memory. The E200 is ideal for RAID 0/1 and has128 MB 
battery-backed write cache (BBWC) module for RAID 5."


Here's what I read between the lines in this description.

  - This is a first generation product. It could be solid and stable or 
it might not.

  - This is an ENTRY LEVEL product. This can mean different things and 
doesn't necessarily imply that it will not deliver the performance you 
are looking for. However, it probably means that there are other cards 
that will deliver higher throughput under heavy load.

  - The card is referred to as being ideal for RAID 0/1. It supports 
RAID 5, but the wording seems to imply that the card is not specifically 
designed to deliver high throughput RAID5 workloads.


Again, I don't mean to imply that this card is unsuitable for your 
application. You first have to have a good handle on what your expected 
workload is going to be. Then you should performance test the card to 
ensure that it delivers the throughput that you require. Based on what 
you've said so far, you have no way to actually predict what your 
expected workload is, in terms of average I/O request size and number of 
I/O requests per second.

Michael