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 19:01] – [Should I emulate?] sgriggs | ||
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==== Should I emulate? ==== | ==== Should I emulate? ==== | ||
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+ | Maybe. Let's talk in terms of scenarios and showstoppers and give some examples. | ||
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+ | 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, | ||
+ | * You read the word " | ||
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+ | Here are some scenarios that would be **excellent** migration scenarios. | ||
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+ | * You have an old VAX or Alpha with no special hardware, the system isn't under heavy load, and all you really need is a box to run some old application software or host a legacy database. The system just sits on a single IP and runs it's application from local disks. You'd probably be happy with **any** emulator in this case. | ||
+ | * You have an old Sun box and it's presence in the data center is getting you dinged by security and other IT groups because of it's age. You know that running the hardware is cheaper than buying an emulator, but your problem is more than financial. You **must** get rid of that hardware so you stop being hassled by the clueless security people who (incorrectly) believe old systems cannot be secure or made secure. So you are willing to pay extra to have the hardware go away while keeping the OS and applications it runs. Remember when it comes to Sun, your only valid option right now would be Charon-SSP and it's super-expensive. So, it has to be worth it! |
when_to_migrate_a_classic_unix_system_and_where_to_migrate_to.txt · Last modified: 2020/03/04 19:04 by sgriggs