Okay so OpenVMS wasn't just FileSystem clustering.
It was physical PC clustering. So I group of networked computers appeared like 1 physical computer. While a MESO or DCOS can do this today, they don't offer durability.
On OpenVMS clusters if the machine running a job physically explodes you don't lose data. RAM and process state is network synchronized.
This allows for rolling upgrades. Your cluster can update and reboot 1 box at a time, but your apps never actually stop, TCP connections are never dropped ETC. For large corporations who've gotten used to these features they're awesome to hold onto.
Yes. I saw the last days of a VMS cluster (actual VAX not Alpha) system being ported to windows/vb/com/asp. The speed difference was actually incredible. It ended up on a mediocre single Xeon 500MHz P3.
At the end of the day, the windows based system was just as reliable as far as nines went and tens of times faster.
This was only just recently replaced with asp.net I understand. They got nearly 20 years out of each rewrite.
You're confusing hardware speed with the software/IPC measurement - the fastest VAX machine ever made ran at 100Mhz (or maybe 120), with 10Mbit ethernet and SCSI-2 I/O paths (1MB/s on a disk or so).
If you found a 486/100 and compared raw compute speed, the vax would likely have won for most cases, because it has 4x the registers.
I'm not actually sure about the clustering IPC performance, but you are essentially comparing hardware about 3-4 generations apart and blaming the software for the issues.. if you were comparing with 500MHz Alphas, etc, then you might have a point..
It was physical PC clustering. So I group of networked computers appeared like 1 physical computer. While a MESO or DCOS can do this today, they don't offer durability.
On OpenVMS clusters if the machine running a job physically explodes you don't lose data. RAM and process state is network synchronized.
This allows for rolling upgrades. Your cluster can update and reboot 1 box at a time, but your apps never actually stop, TCP connections are never dropped ETC. For large corporations who've gotten used to these features they're awesome to hold onto.