FRODO::MOSS@cs.umass.EDU ("Eliot Moss, GRC A351B, x5-4206") (03/18/87)
VaxStar's (officially MicroVax/VaxStation 2000's) come with room for a disk in their box, and two disks are standardly offered: the RD32 (40 megabytes) and the RD53 (about 70 megabytes). While it is not mentioned in the DEC configurations, etc., is it in fact POSSIBLE to put in an RD54 (150 megabytes)? What difficulties might be encountered? We may actually be able to perform a test, since we have a "seed" unit VaxStar from DEC, but if anyone out there in netland has specific knowledge, we would appreciate hearing about it. Comments from DEC engineers are welcome! Except for the disk space limitations, VaxStar's meet my project's needs. I would prefer each system to have its own disk, since providing a server for diskless workstations will probably somewhat reduce performance, definitely reduce the number of workstations I can afford, give a single point of failure (the disk server), and reduce our ability to provide a mix of VMS and Ultrix systems -- not mention force reliance on less well debugged software (LAVC or NFS (which is not even available yet)). But some of the things we want to do simply will not fit on an RD53. I don't like the 6 megabyte main memory limit either, but might be able to live with it; while we're at it, are there any rumblings that indicate that that limit can be gotten around? Perhaps a later upgrade to bigger memory chips? Or a bigger piggyback board? I can understand DEC's position that these are low end systems and that they don't want them too upgradeable, since it would undermine there other MicroVax offerings. But there is a factor of two price jump to the next system, which will encourage a lot of pressure towards the sort of things I am suggesting in this note. A more continuous spectrum (e.g., not dropping the MicroVax RC) would have been more reasonable from a consumer's point of view. The point is, if all I need is increased disk space and a low end system is otherwise satisfactory, I shouldn't have to spend three times what the disk costs just to get up to a system that lets me plug in the disk -- especially when the disk in question is in the same technological family. That is, I can understand about not being able to put an RA81 on a VaxStar, but why not an RD54? Enough opinion! Please send your answers (if you have them) to: MOSS@cs.umass.edu and thanks!
amr@rti-sel.UUCP.UUCP (03/20/87)
In response to the query about placing RD54s in VAXstation 2000's, there "could be" at least two technical problems with the system: 1. Power consumption for the RD54 might be worse than for the RD53, and could exceed limits on the 2000's power supply. 5.25 in. hard disks seem to vary greatly in power consumption, especially when you look at startup (spinning up) surge currents. 2. Heat could also be a problem. The VAXstation has one (1), quiet (i.e. less airflow) fan, compared to the several higher airflow fans in a BA123 box (I can certainly attest to this, I can't even begin to hear the VAXstation 2000 across the room from my desk due to the noise from the GPX that I use). I too would be interested in knowing whether either of these problems actually "do" exist, so post the results if you decide to perform a test. Consider standalone operation carefully though, even if you do add an RD54 to a VAXstation 2000. With EITHER an RD53 or an RD54 in the box, there is no space for other disk storage IN THE SYSTEM UNIT (not even the floppy drive). These systems will have no removeable media for backups or file transfer. Either the TK50 expansion box or contact with a network (along with use of DECnet and RSM, LAVC, or NFS) will almost certainly be needed for reliable backup purposes. -- Cheers, Alan Roberts Research Triangle Institute (decvax!mcnc!rti-sel!amr)