K Class and N Class Internal Disks

[doris grady]

Hello,
Can 18GB, 36GB internal K class and N class disks be used in an external array? Like an existing Jamaica we have. We are doing some server replacements and need to know how much flexibilty we possess.
Thanks.

[Pete Randall]

The K class definitely not, the N class probably not. The problem with all these HP disks is that the mount is slightly different in all of them and something that will fit into your N class slot is probably not going to fit into your Jamaica slot.


Pete

[Jeff Schussele]

Hi Doris,

Yes, but you'll need to come with Jamaica carrier enclosures for them. The internals have only snall connector type add-ons. The Jamaica drives have that black "box" the drive sits in.

HTH,
Jeff

[A. Clay Stephenson · Accepted solution]

Not directly. The Jamaica enclosure requires a disk module that among other-things makes hot-plug possible and provides proper cooling. The disks will not directly fit into an A3312A (Jamaica) enclosure. It may be possible to replace some of the smaller existing Jamaica disks within these modules with larger drives. If you do so, pay very careful attention to the SCSI protocol used by the original and replacement drives. You should also note that the A3312A could support both SE-SCSI and HVD-SCSI disk modules (not on the same bus, of course) and even in the case where the disk module itself is HVD SCSI, the disk may not be HVD because the disk module also has a board that could convert HVD SCSI to something else.

[Torsten.]

FYI: the internal K-Class drives are HVD drives, directly mounted to the chassis, non hot plug.

the N-Class drives are hot-plug LVD drives, mounted on a small frame.
You'll need for every external chassis the appropriate mounting kit / carrier.

You can't directly use the internal disks in an external chassis.

[TwoProc]

The disks that were of a compatible type for the Jamaicas were the drives from the D-class servers as well as the disks from the Autoraid servers.

[Ted Buis]

The K class internal drives were were Fast Wide Differential a.k.a. high voltage differential. The Jamaica enclosures A3311A and A3312A were typically FWD (HVD), but could also have been single ended. You cannot mix the two types so be careful. Also, you would need the physical carriers which are different. The N-class used LVD drives that are not at all compatible with the A3311A or A3312A. You must be very careful, since you cannot mix FWD (HVD) with anyother SCSI drive types.

[SteveB CR]

The Jamaica HASS Arrays often use converted LVD disk drives with 80 pin connection, converted to FWD. The K Class servers also use LVD drives on occasion with a different FWD converter for connectivity. The N class Servers use a straight LVD 80 pin hotswap disk, which can be converted.

I recommend first pulling the hard drives and checking the connectivity each drive physically posseses. Once you've figured this out you can buy the Jamaica enclosures accordingly.

The oldest revision A3647A 4GB FWD disk for The Jamaica in a hotswap enclosure used a 68Pin FWD disk drive, like the internal disks in K Class servers.

The newer Revison A3647A HotSwap enclosure drives used 80 Pin SCA disk drives, and therefore will convert LVD disk drives to FWD to be plugged into your Jamaica and run on the same SCSI chain as the K class disks.

All in all your best be will probably be to buy something along the lines of an SC-10 Disk Enclosure and back all of the servers up to their own disks, then make duplicates of the disks simply because the older drives have got to be running up there in age and I wouldn't bet their lives will be much longer than they already have.