Linux 3.10 Kernel Integrates BCache HDD/SSD Caching
Phoronix: Linux 3.10 Kernel Integrates BCache HDD/SSD Caching
After being in development for more than one year, BCache was finally merged on Wednesday into the mainline Linux kernel code-base. BCache serves as an SSD caching framework for Linux by offering write-through and write-back caching through a newly-exposed block device...
If the cache is an HDD, bcache would throttle it the first time it seeks, ignore it for streamed io, and generally keep it empty. You can tune or disable both features, at the risk of making things slower. HDDs need a lot of readahead which bcache has no reason to do.
There are plenty of other options when no SSD is involved. Bcache is flexible with respect to backing devices, but it must have an SSD to cache to.
doesnt writing and above all rewriting shorten an SSDs life time?
Technically... yes. But they are generally pretty good. I know most new Intel ones have the guideline of "10Gbs of data, a day, everyday, for 5 years." Is when it will die. And even then I think it just goes into Read-Only mode instead of dying completely, so you can still get your data off. Also most of the time you're looking to replace the drive anyway before that time limit kicks in. I know the SSD in my laptop will be replaced in a year and a half or so when I get a new laptop, so im not really worried about it.