The issue that I remember was that we had so many SQL Server databases that it was impossible to keep anything vaguely approaching a sane backup strategy; SQL Server just isn't designed to handle as many as we had. (I in fact remember talking to a famous SQL Server consultant [edit: this was likely Brent Ozar] we were using who said "that won't work," and then I or someone else was tasked with talking to a SQL Server dev at Microsoft about it and they ALSO said that it couldn't work, and when I brought this up, I was told that Microsoft was wrong. IIRC, the implication was that it would take an extremely long time (many days) to restore, and that the snapshots would likely be days old. I don't think any of that contradicts your memory about the very a slow restore going on, but might add some color.
(Likewise, Kiln supported multiple backend instances and had admin commands to copy and move repos between them, so it the SAN had specifically been the issue, we had workarounds that would've been fine with whatever EBS was up to those days. But I remember the databases being the blocker.)
Our "One database per tenant" model was also the reason we were so slow to go to AWS-- the MSSQLServer licensing terms were cost-prohibitive.
However recognizing that around 90% of the FogBugz databases were free-tier and didn't get daily changes meant that teaching the backup scripts to skip creating redundant backups solved most of the issue.
Post-Sandy, I was able to solve most of this by:
1) Shipping full, diff, and incremental backups at different schedules
2) Scripting the ability to create warm standby servers powered by the latest fulls, then diffs as they come online, then the logs at the cutover time. (so you can provision a new server and seamlessly cut over to it)
3) Using our own scripts instead of the RedGate tool (which was _fine_ just not equipped to handle as many DBs as we had) to orchestrate the backups and restores. This in particular was needed for the "only back up modified dbs" fix.
This got us to most of what we wanted-- 0-downtown transitions of databases across servers, nightly offsite backups, fast backup runs. The final problem-- if our datacenter evaporated and we had to reprovision everything from scratch -- was left as an acceptable risk of "we'll fetch the nightlies from s3/Glacier while we do the slower part of rebuilding our servers."
But to your point, during Sandy, none of the above had been fixed yet. I think our sysadmin team was very strong, but they weren't programmers (and/or didn't have enough time to step back and program), and I was able to pick a lot of low hanging fruit in DevOps
There is no reason that they couldn’t have had more than 1 DC when Sandy hit.
Not everyone is built the same, thankfully.
I guess it helps that I grew up in a rural place and did construction for a while, so lugging gas to a generator wasn't a new thing for me.
Also I was... 25? I'd be more cautious today, I think.