Microsoft/FASTER

// Set things going...
var device = Devices.CreateLogDevice(@"C:\Temp\Foo.log");
var kv = new FasterKV<MyThingKey, MyThing>(
    size: 1L << 20,
    logSettings: new LogSettings { LogDevice = device },
    serializerSettings: new SerializerSettings<MyThingKey, MyThing> {
        keySerializer = () => new MyThingKeySerializer(),
        valueSerializer = () => new MyThingSerializer()
    }
);
// I have plain old string keys, but unfortunately I have to wrap them
// to satisfy IFasterEqualityComparer<MyThingKey>.
var session = KV.NewSession(new SimpleFunctions<MyThingKey, MyThing>());

// Carry out some updates...
{
    var key = new MyThingKey("abc");
    var status = session.Upsert(ref key, ref myThingAbc1, Empty.Default, 0);
}
{
    var key = new MyThingKey("def");
    var status = session.Upsert(ref key, ref myThingDef, Empty.Default, 0);
}
{
    var key = new MyThingKey("abc");
    var status = session.Upsert(ref key, ref myThingAbc2, Empty.Default, 0);
}

// Update the on-disc data.
var cpguid = default(Guid);
kv.TakeHybridLogCheckpoint(out cpguid);

// At this point, at least, I would expect to see C:\Temp\Foo.log,
// alas I don't.