...consider doing an open fermentation at least initially so your yeast gets enough oxygen.
OR you could hit it with an additional dose of oxygen ~ 12 hours in. Sanitation is really important in beers that you intend to keep around for years.
Most poor barleywines suffer from either under-attenuation or (most often) yeast stress flavors. Pitch plenty of fresh yeast, oxygenate the hell out of it, dose more O2 12 hours later, and religiously control fermentation temp. Slowly raising then holding the temp near the end of fermentation will help drive attenuation and reduce diacetyl/acetaldehyde.
Lots of great homebrewers pitch the entire cake from a previous batch, but it really is overkill. It definitely beats over-pitching, but I'd rather harvest a few cups of the good stuff and leave the dead yeast/trub behind, especially since the beer could spend a relatively long time sitting on it.