when_to_migrate_a_classic_unix_system_and_where_to_migrate_to
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when_to_migrate_a_classic_unix_system_and_where_to_migrate_to [2020/02/28 21:23] – [Emulation Considerations] sgriggs | when_to_migrate_a_classic_unix_system_and_where_to_migrate_to [2020/03/04 18:08] – [Should I emulate?] sgriggs | ||
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- __It's old.__ Well, diamonds and Frank Sinatra are old too. We do notice that sometimes younger IT people or business minded folks often see the age of a system as a liability. However, consider how long the company has been benefiting from that system sitting there and just doing it's job without additional charges or effort. Consider that, over the years, many of the bugs and problems with the system got worked out. It's also probably familiar to many of the end-users and changing it might pinch productivity and morale. It's not always great to swap out some " | - __It's old.__ Well, diamonds and Frank Sinatra are old too. We do notice that sometimes younger IT people or business minded folks often see the age of a system as a liability. However, consider how long the company has been benefiting from that system sitting there and just doing it's job without additional charges or effort. Consider that, over the years, many of the bugs and problems with the system got worked out. It's also probably familiar to many of the end-users and changing it might pinch productivity and morale. It's not always great to swap out some " | ||
- | ==== Emulation | + | ==== Specific Emulator |
There are several strong emulation suites for Alpha hardware. Let's just list those out first. | There are several strong emulation suites for Alpha hardware. Let's just list those out first. | ||
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==== Should I emulate? ==== | ==== Should I emulate? ==== | ||
+ | |||
+ | Maybe. Let's talk in terms of scenarios and showstoppers and give some examples. | ||
+ | |||
+ | Terrible Migration Scenarios | ||
+ | * You have an old Unix or VMS machine and it's connected to an old storage array, SAN, or custom hardware like LAT based terminal servers or serial concentrators. Emulation gives you few options to integrate the new hardware. Yes, SCSI pass-through works, but it's not going to help you with non-SCSI hardware that cannot be emulated like WAN/ATM cards, or high speed controllers like Infiniband or Myrnet. | ||
+ | * You have a GS1280 (baddest king-daddy Alpha server ever made) with lots of EV7 processors. You had to buy that thing because it was the only beast capable of handling the load. You have alpha-only binaries for VMS or Unix and can't port them. You'll **hate** emulation. It'll be less than half the speed of your GS1280. Those big Wildfire line of servers will stomp the guts out of emulation' | ||
+ | * You make very heavy use of MSCP based RAID controllers and you want to emulate those as well: Don't. There are better options when moving to emulation. | ||
+ | * You have some development environments on your VAX and some non-critical servers you'd like to ditch the hardware and emulate. Well, emulation is a good option in this case but why pay big bucks for it when SIMH is probably the best VAX emulator (free or otherwise). You should be using SIMH for free. It's easier to make work, has accurate emulation, generally results in some performance gains, and has a more sane and accessible system than the commercial VAX emulation suites. If you can get by without having support, then SIMH is always a better option for VAX emulation. The two commercial options should be 2nd and 3rd in that case. | ||
+ | * You have moved most of your infrastructure to VMware or something similar and now you want to emulate your Unix or VMS hardware so you can move that to VMware too. That's not a great reason. You are going to probably spend (lots) more on the emulator than real hardware. So, is it **really** worth it? Also, running emulation inside VMware is something the emulation vendors love to crow about. Unfortunately, |
when_to_migrate_a_classic_unix_system_and_where_to_migrate_to.txt · Last modified: 2020/03/04 19:04 by sgriggs