Re: SSD as Cache?

[Neal Murphy <neal.p.murphy@alum.wpi.edu>]

On Friday, November 08, 2013 09:12:08 AM basti wrote:
> Hello,
> 
> on my Webservers, I have 1x 128GB SSD and a Raid 1 (1TB).
> 
> Now I plan to improve the performance of my Webapplication.
> The Cache is about 10.0 GB in 2000000 files.
> 
> Can this cache moved to SSD?
> Months ago I read articles about SSD and Flash Memory like:
> - "Disable logging on SSD"
> - "Disable cache on SSD"
> - "Don't swap on SSD" ...
> 
> And today?
> How long will the SSD work without data loss?

Using the -noatime mount option will extend the lifetime of the SSD. The final 
lifetime depends on how heavily the servers are used. If they're used 24x7 and 
the cache is always changing, you might get a year or two out of the SSD.

RAM is fairly cheap these days. Instead, if you can, increase RAM by 16GiB, 
leave the cache on rotating media, and let Linux cache the files in RAM. After 
that, performance improvements will come from fixing inefficient code.