From: blockedofcourse@foo.invalid   
      
   On 12/12/2025 12:15 PM, Waldek Hebisch wrote:   
   > Don Y  wrote:   
   >>   
   >> I.e., the mounting holes for SAS and SATA drives are identically placed.   
   >> So, I can mount a SATA or SAS drive on a SATA sled or a SAS/SATA sled.   
   >> (there's nothing preventing the SAS from being mounted on the SATA-only   
   >> sled).   
   >>   
   >> So, I *could* "force" that sled into a SATA-only backplane.   
   >>   
   >> I.e., the better solution would have been for the drives to have different   
   >> mounting hole patterns so you could NOT mount a SAS drive on a SATA-only   
   >> sled and have the connectors trying to mate.   
   >   
   > PC tradition is that you can plug-in appropriate interface card   
   > and connect new devices.  AFAICS currently nothing prevents   
   > puting SAS drives into drive bays originally carrying SATA drives   
   > and connect the drives to SAS interface.   
      
   The sleds are required in order to SLIDE the mounted drives into a card   
   cage.  Unlike a PC -- where you manually attach power and data cables to   
   the connectors -- the backplane presents a set of FIXED connectors to   
   which the drives mate.   
      
   Backplanes come in a variety of configurations based on the physical   
   constraints of the machine's package.  Most of mine are 8 3.5" slots;   
   four on the top (drives sliding in "on edge") and four on the bottom:   
   ||||   
   ||||   
      
   Some have 4 drives stacked horizontally.   
   _   
   _   
   _   
   _   
      
   Others have 1+1+2+2+2.  Or, 2+2+2+2.  (machines that use 2.5" drives   
   exclusively -- instead of adapting them to a 3.5" sled -- may have 20   
   or more side by side, "on edge".   
      
   The only "loose (disk) cabling" is for optical drives.   
      
   > Different pattern of   
   > mounting holes would make this harder.  Of course, some manufacturers   
   > play such games and introduce gatitious incompatibilities.   
   > But ATM it seems that drive makers are reasonable with placement   
   > of mounting holes.  Different connectors are enough to prevent   
   > accidental wrong connection, and connectors are relatively   
   > low value items compared to drives, so there is less trouble   
   > with stocking different types of connectors.   
      
   But a broken connector renders the drive or backplane slot unusable.   
      
   Here's an example.  I suspect someone tried to force this drive   
   into a SATA connector (note the area to the left of the keyway):   
      
      
      
   The break isn't just superficial; one can bend that part of the   
   connector downward as the crack extends "into" the connector body.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)