Read the summary and para above in this link:???
Any serious reference for that opinion?
How does ZFS RAIDZ compare to its corresponding traditional RAID when it comes to data recovery? Simplicity of RAID5 vs complexity of RAIDZ.
My gripe with ZFS in this instance isn't with the rate at which the file system tends to fragment files, it is that there is no in-place recourse to defragment. I'd prefer to get stressful defragmentation done before a disc failure occures rather than effectively dealing with disk fragmenation after when data is most at risk.Copy on Write filesystems suffer more fragmentation than older filesystems but the advanced ZFS rambased read/write cache reduces small read i/o to a fraction. It is not unusual to see 80% cache hit rate with enough RAM. The variable blocksize is a nice feature when you write datablocks < recsize. If the data to be written >=recsize, all pieces are written in recsize (up to 1M)