1. A method of managing access requests for resources stored on a storage system, the method comprising: under control of a storage system comprising a plurality of storage devices, each storage device comprising a device access level, the device access level comprising a normal access level and a stalled access level, the normal access level indicating that response to access requests to the storage device is normal and the stalled access level indicating that response to access requests to the storage device is slow, directing a first access request by a thread for a resource stored on the storage system to one or more storage devices comprising normal access levels near the time of the first access request; and if the first access request by the thread fails, directing a second access request by the thread for the resource to one or more storage devices comprising normal access levels near the time of the second access request and one or more storage devices comprising stalled access levels near the time of the second access request.