Nostalrius Begins - Quality wow vanilla realm (1.12)

I've always wondered how casters and other mana-using DPS keep their mana up over the span of 4-5 minute raid boss fights?

Do they just downrank spells or what? Do they have to chug potions along with using class abilities like evocate or life tap? With vanilla spell costs, I'm having a hard time imagining a Mage sustaining 5 minutes of casting. Only way I can see it happening is by downranking to just the right rank where you can spam it nonstop with potion+evocate+mana gem on cooldown.

Though, I'm not entirely sure which caster DPS are even raid-viable in the first place, outside of mage and warlock.

Drinking mana-pots galore, evocation, innervate etc yes. Also, there arent many fights lasting as long as 5 minutes in current content or BWL. Exceptions would be Razorgore and Nefarian basically.

EDIT: Also those stones from scholo trash that sacrifices health for mana.

Mana pots on cooldown and life tap.

dark rune / demonic rune / mana potion. and as stated before, current content doesnt last all too long

Dark runes, demonic runes, mana potions, mp5 consumables, class abilities (life tap, innervate, evocation, etc.)

And for a mage, make different rank mana gems, pop.as soon as u burned enough mana to use 1 to top you off. Putting it on cd.

If you are Alliance and have a Pally in your raid, you can wand the mob while he maintains JoW.

Consumables.