I disable the disk cache of RAID controller,  unfortunately it still lost some data.

2011/6/1 Peter Schuller <peter.schuller@infidyne.com>
> 1). set commitlog sync in batch mode and the sync batch window in 0 ms
> 2). one client wrote random keys in infinite loop with consistency level
> QUORUM and record the keys in file after the insert() method return normally
> 3). unplug one server (node A) power cord
> 4). restart the server and cassandra service
> 5). read the key list generated in step 2) with consistency level ONE

How sure are you that the system is honoring fsync() properly,
including flushing any caches on underlying drives? Or is this with
battery backed caching RAID controllers?

/ Peter Schuller

by Preston Chang