<<< OFFICE$DISK:[NOTES$LIBRARY]HARDWARE_AND_MAINTENANCE.NOTE;1 >>> -< Hardware and Maintenance >- ================================================================================ Note 1.0 Welcome ... No replies OPNOFF::SYSTEM 5 lines 21-AUG-1992 11:58 -------------------------------------------------------------------------------- Welcome to VAX NOTES This conference is for discussions relating to Hardware and Maintenance ================================================================================ Note 2.0 10BaseT conversion No replies OPNNET::POWELLH27 17 lines 24-AUG-1992 15:48 -------------------------------------------------------------------------------- We will have to convert to 10BaseT in the next 12 months using a fibre backbone. We propose to use DEChubs with terminal server and ethernet devices on them. I'm not sure what brand of Fibre Optic Transceiver was proposed. Are there any traps in converting to 10BaseT? Are there any performance issues I should be aware of and is there software I should buy (we currently use none). We have a relatively small network (<100 devices) but they will be distributed over 7 floors in a single building. Cheers, Harry Powell P.S. Does anyone want to buy ~60 DEPCA Turbo's cheap? ================================================================================ Note 3.0 Can DSSI disks be on VAX 3xxx 5 replies OPNNET::BRAGGB13 13 lines 26-AUG-1992 09:11 -------------------------------------------------------------------------------- Query: Is is possible to have DSSI disks connected to the MicroVAX 3xxx range, in particular the new 3100's. I've seen a few sideways references that suggest that this is possible (eg the abstract for session 218 in the symposium guide), but no hard data. We own a 4000-200, and would like to dual path the DSSI disks to a yet to be purchased node; and 3100's are a lot cheaper than 4000's !!! Any advice would be greatly appreciated. Bill Bragg ================================================================================ Note 3.1 Can DSSI disks be on VAX 3xxx 1 of 5 OPNNET::MCNICOLP12 5 lines 26-AUG-1992 13:39 -< Unsubstantiated Rumor >- -------------------------------------------------------------------------------- I heard from a bloke who heard it from a bloke who heard it from a bloke ... A 3100 capable of supporting DSSI devices is on the way. For all I know it might even be here (wherever "here" is). ================================================================================ Note 3.2 Can DSSI disks be on VAX 3xxx 2 of 5 OPNNET::POWELLH27 8 lines 26-AUG-1992 14:49 -< It may be possibler >- -------------------------------------------------------------------------------- The new 4100 has a DSSI port so no problem there. If the "new" 3100 also has one your problems are solved. If not, you need to get to QBUS somehow so you can use a KFQSA adaptor to get DSSI. ================================================================================ Note 3.3 Can DSSI disks be on VAX 3xxx 3 of 5 OPNNET::WALLACEK21 4 lines 26-AUG-1992 15:13 -< No DSSI on 3100/80 >- -------------------------------------------------------------------------------- The MicroVAX 3100 Models 10, 10e, 20, 20e, 30, 40 and 80 are SCSI only for disk - definitely no DSSI on these models. I understand that the Model 90 will also be SCSI only. ================================================================================ Note 3.4 Can DSSI disks be on VAX 3xxx 4 of 5 OPNNET::HAWLEYD13 "Dave Hawley, IT Manager, Tektroni" 4 lines 27-AUG-1992 09:52 -< Stick to the 4xxx >- -------------------------------------------------------------------------------- The "smallest" DSSI 3xxx machine currently is the 3300, now over four years old, and about 2.5 VUPs. It's a Qbus machine as well. You would definitely be better running the 4xxx range - horsepower plus connectibility for the same price. ================================================================================ Note 3.5 Can DSSI disks be on VAX 3xxx 5 of 5 OPNNET::DAVISS25 11 lines 27-AUG-1992 11:40 -------------------------------------------------------------------------------- There are currently 3 ways to get to DSSI... 1) Integral DSSI interface - such as the 3400 series or 4000 servers. 2) XMI based machine via the KFMSA interface 3) Qbus via the KFQSA interface. One of the above must be utilized. Embedded SCSI systems do not currently have a direct DSSI path. Scott ================================================================================ Note 4.0 Stock Exchange Ethernet? 6 replies OPNNET::ROSSR12 "Rollo Ross, Uni SA" 13 lines 26-AUG-1992 09:36 -------------------------------------------------------------------------------- From yesterday's Australian: > A glitch in the Stock Exchange Automated Trading System - SEATS - >brought the sharemarket ot a halt yesterday morning... > > Mr Tom Quinn, the stock exchange's national manager, production, >said the problem arose when the ethernets failed. "There is no way you >can connect all the computers to two of these ethernets" he said. "You >can't have a hot one standing by. If it fails, we simply go to the >storeroom and wheel a new one out." Just "wheel out another ethernet", huh? Maybe Malcolm Wade can tell us what really happened, without the information-entropy introduced by a journalist. ================================================================================ Note 4.1 Stock Exchange Ethernet? 1 of 6 OPNNET::CAMERONJ12 1 line 26-AUG-1992 10:18 -------------------------------------------------------------------------------- Yes please! ================================================================================ Note 4.2 Stock Exchange Ethernet? 2 of 6 OPNNET::WADEM15 "Malcolm Wade" 23 lines 26-AUG-1992 15:51 -< You wanted answers ... >- -------------------------------------------------------------------------------- Jeez are we copping flak over this one. From what I know and have been told, one the baseband ethernet segments in our Sydney data centre went haywire. This is the segment to which the SEAT trading system is connected. The problem became apparent on monday morning as the load on the network increased. We don't don't run duplicate ethernet segments in the data centre. So, although the quote is not exactly correct, they ended up by dragging out a spare piece of baseband cable and connecting things that way to get the whole lot up and running. It was not a VAX hardware problem (I have heard this quoted somewhere too). Malcolm Disclaimer: I work for the Australian Stock Exchange. However, I do not work on the SEAT system, nor do I have any responsibilities in the network area or with the hardware involved. The information supplied above is what I have been told from other colleagues. If you require more information you should contect the Stock Exchange directly. ================================================================================ Note 4.3 Stock Exchange Ethernet? 3 of 6 OPNNET::CAMERONJ12 1 line 26-AUG-1992 18:15 -------------------------------------------------------------------------------- Interested. What type of cable is baseband ethernet? ================================================================================ Note 4.4 Stock Exchange Ethernet? 4 of 6 OPNNET::WADEM15 "Malcolm Wade" 6 lines 27-AUG-1992 08:48 -------------------------------------------------------------------------------- >Interested. What type of cable is baseband ethernet? You know ... the thickwire type (maybe I got my terminology wrong ... we're talking about the stuff you connect H4005's to). M. ================================================================================ Note 4.5 Stock Exchange Ethernet? 5 of 6 OPNNET::CAMERONJ12 17 lines 27-AUG-1992 09:38 -------------------------------------------------------------------------------- Re: Note 4.4 by OPNNET::WADEM15 > You know ... the thickwire type [...] Oh yes. The tough stuff that can't turn corners quickly. The bits fall off. Yes, I've had trouble with that too; in a previous job. In one case a dent in the shield caused some interesting non-operating behaviour; totally changed the RF nature of the cable. We even got to use one of those cable short locators; but it turned out not to be an absolute short... The only troubles I ever seem to have with thinwire is that the connectors fall off; shield first, leaving just the core. This works quite well; for a few months. James ================================================================================ Note 4.6 Stock Exchange Ethernet? 6 of 6 OPNNET::LOCKHARTA9 11 lines 28-AUG-1992 09:09 -< Ethernet Cable Testing >- -------------------------------------------------------------------------------- Suggest you consider obtaining something like a TDR (Time Domain Reflectometer) Techtronics make one, bit pricey- about $10k but a great investment can provide a complete picture of the cable characteristics both on screen and hard copy print which can be used for future reference incase a problem occurs you can compare signature changes on the cable and identify a problem down to the 10th of a metre. If you cant justify buying one then there is still the option of renting from Tech Rentals dont know there phone number. If anyone wants more details, please feel free to contact me- Andrew Lockhart - Coles Myer Ltd 03 829 6929 93 ================================================================================ Note 5.0 3rd Party Maintenance No replies OPNNET::KNOCKR26 2 lines 26-AUG-1992 13:25 -------------------------------------------------------------------------------- I am interested in the performance/acceptibility of 3rd party maintainers for VAX hardware. ================================================================================ Note 6.0 DECRouter 250 1 reply OPNNET::POWELLH27 4 lines 26-AUG-1992 14:53 -------------------------------------------------------------------------------- I am in the market for a DECRouter 250 (DECWanRouter 250?). Does anyone have a pre-loved one they don't want? ================================================================================ Note 6.1 DECRouter 250 1 of 1 OPNNET::NORTHB25 3 lines 27-AUG-1992 17:53 -< DEcrouter-150's >- -------------------------------------------------------------------------------- We have some Decrouters-150's that could be available. Call me next week on 02/953-3842 if there is any interest. Bruce North, NPR ================================================================================ Note 7.0 Q-bus bottleneck ? 6 replies OPNNET::GARNERR30 "Robin Garner" 6 lines 27-AUG-1992 10:12 -------------------------------------------------------------------------------- I'm in the process of configuring a dual-host 4500 cluster, which unfortunately requires more than 12 disks, and hence requires a KFQSA to support the remainder. The Q-bus is obviously going to be the perfoemance bottleneck in this cluster, but does anyone have any first-hand experience with this type of configuration ? How concerned should I be about this bottleneck ? ================================================================================ Note 7.1 Q-bus bottleneck ? 1 of 6 OPNNET::POWELLH27 6 lines 27-AUG-1992 10:21 -< Should not be a problem >- -------------------------------------------------------------------------------- We are using KFQSA adapters with RF31 and RF72 drives and have not had any problems. The since you can have only 6 drives on a bus (with 2 cpus) all disks would need to be going at a sustained 30 I/O's per second to flood the bus which is probably unlikely. ================================================================================ Note 7.2 Q-bus bottleneck ? 2 of 6 OPNNET::HAWLEYD13 "Dave Hawley, IT Manager, Tektroni" 4 lines 27-AUG-1992 10:35 -< KFQSA performance >- -------------------------------------------------------------------------------- WARNING! The KFQSA has about 1/4 the throughput of the built-in DSSI adapters in the 33/3400, etc. This is actually a Qbus limitation! However, the previous comment holds true ... you would have to be really flogging the disks continuously to saturate/bottleneck things. ================================================================================ Note 7.3 Q-bus bottleneck ? 3 of 6 OPNNET::CAMERONJ12 19 lines 27-AUG-1992 10:40 -< Use It For Swapfile >- -------------------------------------------------------------------------------- Re: Note 7.0 by OPNNET::GARNERR30 > The Q-bus is obviously going to be the performance bottleneck I'd just be careful to make sure the I/O's that go to the disk are not big ones. If you have a large indexed file that is read randomly, in small pieces, and not often, then you won't notice much difference between having off the Q-bus and having it somewhere else. Do not use it for pagefile. Terrible performance. Consider using it for swapfile. Let's face it, if the system gets so down on resources that it has to swap, let it take it's time! It'll be able to do more while swapping! Also saves "wasting" fast disk for a file that in theory should not be used. James ================================================================================ Note 7.4 Q-bus bottleneck ? 4 of 6 OPNNET::DAVISS25 9 lines 27-AUG-1992 11:43 -------------------------------------------------------------------------------- Note that there are other differences as well between KFQSA and all other DSSI interfaces... KFQSA is an SSP storage port. THis means no cluster traffic will go over it. Scott ================================================================================ Note 7.5 Q-bus bottleneck ? 5 of 6 OPNNET::POWELLH27 4 lines 27-AUG-1992 13:20 -< New KFQSA adapter >- -------------------------------------------------------------------------------- When you are planning your configuration don't forget that there is a new style of KFQSA adapter out that is not terminated. This means that you can plug 3 cpus in the dssi bus. ================================================================================ Note 7.6 Q-bus bottleneck ? 6 of 6 OPNNET::GRANTA15 11 lines 28-AUG-1992 13:09 -< Swapfile is used by pro-active mem. mgmt. >- -------------------------------------------------------------------------------- >Consider using it for swapfile. Let's face it, if the system gets >so down on resources that it has to swap, let it take it's time! >It'll be able to do more while swapping! Also saves "wasting" >fast disk for a file that in theory should not be used. I'd be careful here. The new pro-active memory management (VMS 5.4-3 and above) swaps out processes that are inactive, even if there is some free memory. The next time you use that process, it could take a while to respond. Alistair. ================================================================================ Note 8.0 Getting rid of HSC 1 reply OPNNET::NAGARAJAR26 9 lines 28-AUG-1992 12:14 -------------------------------------------------------------------------------- I Have a very basic question. Is it wise to get rid of HSC 50 to serve Disks and tapes and go for a XMI type of Controller? How much overhead that would be? The main idea is that we are in the process of down sizing the systems by getting rid of 8350 and replace it by a more VUP rated 3100 Model 80. Also the mainetanace charges for HSC is pretty high by Digital. Has any one has a chaeper solution to replace HSC and connect the disks and tapes on to a 6230 and serve it over a cluster? Thanks ================================================================================ Note 8.1 Getting rid of HSC 1 of 1 OPNNET::MCINTOSHR2 4 lines 28-AUG-1992 14:42 -< Try the KDM70 >- -------------------------------------------------------------------------------- The KDM70 controller is cheaper than a HSC and will be substantially less maintenance also. The KDM70 plugs into the XMI and is good for 8 devices.