Re: Triple parity and beyond
From: Stan Hoeppner <hidden>
Date: 2013-12-02 04:30:57
On 12/1/2013 11:53 AM, Richard Scobie wrote:
Stan Hoeppner wrote:quoted
ZERO SATA drives are dual ported. The vast majority of people using md/RAID are using SATA disks, not SAS.While admittedly uncommon, they are available. http://h30094.www3.hp.com/product/sku/10435415
Assuming that's not a misprint, then this is not a dual ported SATA drive. The SATA protocol doesn't support this. This is a SATA drive in HP's vendor proprietary carrier with a proprietary factory integrated external SAS interposer card hanging off the back. This interposer allows you to add this SATA drive to an HP dual ported SAS enclosure backplane and HBAs. They also offer an interposer to drop SATA drives into FC enclosures. Note these SAS-SATA interposers require SAS HBAs and an SAS enclosure. Given the small price difference between SATA drives w/interposer, and native nearline SAS drives, and the greater reliability/warranty of the latter, I don't think you'll see many folks buying these interposer drives. Especially given the required investment in SAS infrastructure between the drives and host. See: http://serialstoragewire.net/Articles/2007_07/developer24.html http://en.wikipedia.org/wiki/Interposer -- Stan