[OmniOS-discuss] Debating Swapping 2TB with 4TB drives in RaidZ2 or Create new Vol and clone

[Jim Klimov]

23 марта 2014 г. 16:53:38 CET, Bob Friesenhahn <bfriesen at simple.dallas.tx.us> пишет:
>On Sun, 23 Mar 2014, Jim Klimov wrote:
>>>
>>> Regardless, I can not imagine why someone would want to replace 2TB
>>> drives with 4TB drives.
>>
>> Limited number of disk bays? ;)
>
>That would be the only reason.  The cost of replacing existing 2TB 
>drives with 4TB drives seems pretty high.  Performace would only go 
>down, and if the physical block size increases, then storage 
>efficiency would decrease.  Disk bays are not necessarily all that 
>expensive as long as there is a place nearby to put it.
>
>An existing disk chassis could be replaced with one which supports 
>more slots and the existing drives re-used as long as they are 
>physically compatible with the new chassis.
>
>Bob

Engineering is a matter of compromise. Something good for one usecase is not suitable for another.

Consider the users of the popular HP Microserver series limited by 4-5 data disks. Consider the low-power rigs where more spindles might soon double the power draw (think of TCO over time vs. raw price of purchase). For a home nas peak performance might matter less than available volume, and even a "less efficient" storage in terms of slack space might be more efficient for mechanical performance by enforcing smaller fragmentation.

So... YMMV ;)

//Jim
--
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