Dealing with pawn storm on castled queen side

So say in some variations of the French, Sicilian etc where white castles queen side how do you guys deal with aggressive pawn storms from black? I usually have trouble holding them at bay :/

Often it's not possible to hold it at bay with only defensive moves. That sort of play is sometimes just a fundamental part of the position for your opponent. In fact in such situations trying to play on "their" side of the board will often help the opponent.

What you do is create counterplay. Unless you completely screwed up the opening, there will be fundamental things for you too. Play a pawn break in the center or kingside and make your pieces as active as you can in that area.

Even when this turns out badly, it will buy you some time, and create at least a puncher's chance. In contrast when you defend passively, your opponent has a free hand to build the attack forever.

In the french, at least it isn't common for white to castle long.

I'm not saying it can't happen, but I know in my own games rarely does white do this- and one of whites problem (with castling on the queenside) is that the king has invest an extra tempo to hold the rook pawn.

I have a couple of games of mine posted on one of my posts entitled "my best attacks on castled kings" where my opponent and I have castled on opposite sides and he/she is sending a pawn storm on my queen-side where I've castled long. Best refutation is to attack them first before they attack you. One thing to remember--from Kotov and Keres's "Art of the Middle Game", it is generally the guy who's able to get his attack in first who wins the game. If you'd like, I recommend looking at the games of newengland7 vs. giongty, newengland7 vs. virac2015, and newengland7 vs. Sandgroper.