How exactly does a SAS SFF-8087 breakout cable work? + RAID/connection questions

Solution 1:

A few items to help clarify SAS technology...

  • SATA drives can connect to SAS ports.
  • SAS drives cannot connect to SATA ports.
  • Server-class hardware typically uses an embedded RAID controller or a separate RAID controller PCIe device.
  • Most RAID controllers and SAS HBAs will use SAS connections (multilane or 4-lane SAS ports).
  • Internally, these systems will use one of the internal SAS transports (SFF-8087 or SFF-8484) for cabling.
  • 4-lane SAS cables carry FOUR SAS links over the same cable.
  • Enterprise servers will typically have a SAS backplane for hot-swap hard drives. These backplanes can accommodate SAS and SATA disks. The backplanes also provide power to the drives. It doesn't make sense to run SATA cables to hot-swappable hard drives. Instead, the internal SAS cables will link the controller and the backplane.
  • You can mix and match SATA and SAS on the same backplane, but because the protocols are different, bad things. can happen.

Internal SAS 4-lane cabling to a backplane enter image description here


Internal SAS breakout cabling to a backplane enter image description here