Improved techniques are provided for storing bursty data, such as checkpoints, in parallel computing environments. A parallel file system is provided comprising at least first and second storage tiers comprising respective disjoint subsets of storage; and at least one processing device configured to store burst data from a plurality of distributed processes for a given burst operation during the given burst operation on both of the at least first and second storage tiers. The given burst operation comprises a multi-phase input/output (IO) task, such as a checkpoint, having alternating periods of idle time and bursts of write and/or storage activity. A method is also provided for provisioning a parallel file system by obtaining a specification of burst data requirements for the parallel file system and determining an amount of storage required for at least first and second storage tiers comprising respective disjoint subsets of storage to satisfy the burst data requirements.