Re: New idea about RAID and SSD

Massimo Maggi wrote:

Hi,
SSDs have low latency but a high price per GB,
Traditional hard disks have high latency, but high sequential read/write
speed and low price per GB.
Is possibile to use a SSD for metadata, which requires many seeks and is
relatively small, in a special "RAID mode" with a traditional hard disk
for the extents of the real data?
A cheap but performant SSD (maybe 32 GB) + a big and fast HD (maybe 1.5
TB, or two in RAID0 - 3TB ), wouldn't create an array much cheaper than
a ssd-only array of the same size, and much faster (in
not-only-sequential workload)  than one or two traditional HDs in RAID0?
Would it work?
Thank you for your precious time!
Massimo Maggi
massimo@mmmm.it

well, it is not a "new" idea.

yes people are thinking about it, but it is not the most critical
work on the list of things to do for btrfs or any other linux fs.

jim