6/20    I have an MSA20 (a scsi attached raid enclosure) from HP that uses
        SATA disks.  My company is somewhat cheap and I'd like to keep an extra
        disk on hand, but not pay for the nifty drive carrier.  (this way when
        a drive fails, I can just remove it, swap out the disk in the carrier
        and slap it back in without waiting for shipping).  BUT, when I tested
        this it didn't work.  The drives are the exact same model, but there is
        some HP specific printing on the label (and a 4 letter, comma separated
        code, which is different).  I have used dd to insure that the disks are
        have the same bits, but no joy, any of you know what it is that makes
        the HP disk different?  -crebbs
        \_ firmware
        \_ ah the joy of vendor lock-in
        \_ I'm not sure how using HP saves your company money.  There are tons
           of cheapy scsi attached raid boxes out there which will happily
           take any same sized disk to replace a bad drive.
           \_ HP isn't saving the company money.  The product needs to run
              on HP.
              \_ No reason to be tied to HP for storage.  Fine, buy HP for
                 the CPU, but detach CPU/computation from storage wrt vendors
                 \_ You buy HP for the support, and when you buy large, their
                    discounts are deep.  Also, doesn't apply to the MSA, but
                    their EVAs are pretty freakin cool.
                    \_ EVAs are likely way out of the price range for crebbs
                       company.  If they won't buy the right disks they won't
                       buy an EVA.  And yes they're pretty cool.  At least as
                       cool as storage can be, anyway.
                       \_ Why would I want an EVA instead of, say, a Netapp?
                          \_ There's nothing wrong with a Netapp, per se.  Its
                             just that the EVA is 'better'.  I like the EVA
                             architecture better.  Virtual-virtual disks
                             across the whole array with no hot spares doing
                             nothing, the control software is more mature
                             although it does run from a windows box.  In
                             general the EVA is just a more mature and serious
                             product than the Netapp.  I've used the Netapp
                             since before they were anyone.  The EVA is new to
                             me but I prefer it overall.  Of course the EVA
                             will cost a lot more in $/tb but there's a certain
                             amount of "get what you pay for" if you can afford
                             it.  What I don't like about the Netapp is the
                             very patchy way it has developed over time.  New
                             features get jacked in, some hardware level
                             maintenance requires on-site hands but really
                             shouldn't, half the tech problems can be handled
                             by shutting down all the shelves (via big red
                             switch) and powering back up *and not in any
                             other way*.  I wouldn't use Netapp for front line
                             real time 24/7 storage if I could afford better.
        \_ It may not be HP issue, but the drive manufacturer issue.  I've had
           numerous cases where the drives of identical model actually had
           slightly different size(usually by few thousand blocks.)  And if it
           turns out the new drive has smaller # of blocks than the rest of the
           drives, that may be why.