On 9/13/2013 3:25 PM, Derek Piper wrote:
> Having found a posting on this list from July this year, I am trying to
> find if (and how) TRIM support is supported and enabled under RAID 1 with 2
> SSD drives.
The are more important questions to first ask yourself.
1. Will TRIM benefit your make/model of SSDs?
Are they the same brand, model, and firmware? If different brands
or models, or even the same model w/different firmware, the two may
behave completely differently WRT TRIM. One may speed up while the
other slows down.
2. Will it benefit your workloads?
3. How compressible are your files, on average?
4. Which SSDs? SandForce 22xx based? Which firmware rev? See:
http://www.anandtech.com/show/6107/corsair-force-series-gs-240gb-review
5. Do you plan to use realtime discard or batch discard? Most recent
data shows that realtime discard murders performance.
Summary: There is much, much, more to optimizing SSD performance than
getting TRIM working down the stack. In fact some SSDs work better
without TRIM, and some perform worse when TRIM is used.
For many users, TRIM is a solution to a problem they may never have.
They simply want it because they've read somewhere that they should have it.
--
Stan
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