What may be painful is not being able to at least return capital by the end of the fund without a WONDERFUL story about coming liquidity.
Current industry average 10 year IRR is 10% according to Cambridge Associates. You've really fucked things up badly if you can't return capital in year 9/10 on a 10% IRR.
Assuming money is put into the fund in year 0, a return of 2.35x capital in year 9 or 2.6x capital in year 10 is required to get a 10% IRR.
Or even better, is that comparative performance, i.e. 10% better than a vanguard index fund?