On Wed, Jan 22, 2014 at 06:46:11PM -0800, David Lang wrote: > It's extremely unlikely that drive manufacturers will produce drives > that won't work with any existing OS, so they are going to support > smaller writes in firmware. If they don't, they won't be able to > sell their drives to anyone running existing software. Given the > Enterprise software upgrade cycle compared to the expanding storage > needs, whatever they ship will have to work on OS and firmware > releases that happened several years ago. I've been talking to a number of HDD vendors, and while most of the discussions has been about SMR, the topic of 64k sectors did come up recently. In the opinion of at least one drive vendor, the pressure or 64k sectors will start increasing (roughly paraphrasing that vendor's engineer, "it's a matter of physics"), and it might not be surprising that in 2 or 3 years, we might start seing drives with 64k sectors. Like with 4k sector drives, it's likely that at least initial said drives will have an emulation mode where sub-64k writes will require a read-modify-write cycle. What I told that vendor was that if this were the case, he should seriously consider submitting a topic proposal to the LSF/MM, since if he wants those drives to be well supported, we need to start thinking about what changes might be necessary at the VM and FS layers now. So hopefully we'll see a topic proposal from that HDD vendor in the next couple of days. The bottom line is that I'm pretty well convinced that like SMR drives, 64k sector drives will be coming, and it's not something we can duck. It might not come as quickly as the HDD vendor community might like --- I remember attending an IDEMA conference in 2008 where they confidently predicted that 4k sector drives would be the default in 2 years, and it took a wee bit longer than that. But nevertheless, looking at the most likely roadmap and trajectory of hard drive technology, these are two things that will very likely be coming down the pike, and it would be best if we start thinking about how to engage with these changes constructively sooner rather than putting it off and then getting caught behind the eight-ball later. Cheers, - Ted -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>