FreeNAS – ESX and NFS; Synchronous Writes and the ZIL
I’ve been testing FreeNAS lately – connecting ESX hosts via NFS for virtual machine storage. Being POSIX compliant, ZFS must abide by any calls made with the o_sync flag set meaning essentially that all disk activity must be written to stable storage before success is returned. This includes most commonly databases, file server operations and most importantly NFS. This means that the ZIL (ZFS intent log) will be used as a special place on disk in the pool … Read more…