Hi guys,
I've been playing out with a new dell R515 server here with a H700 controller that has 1GB cache. The RAID10 container with 4x 600GB 15K RPM works quite well, and on the same controller I've a 5x2TB raid 5 array. I know the disks are nearline SAS and bla bla bla, but I'm not getting any better than 45MB/sec doing sequencial writes on it. I've been playing with write cache inside the Windows 2008R2 guest and made some differences so sometimes without write cache enabled on the OS the writes goes for some time at 100MB/sec, sometimes until the cache flushes completely but sometimes it goes for quite a long time, like 1 minute or more than again drops to 40-45MB/sec.
I know these drives alone can easily do writes at +100MB/sec eaisly, so 5 of them even on RAID5 with a good controller and lots of cache surely should be able to saturate a gigabit network. I'm a bit frustrated with it :/
Is there anything at the ESXi level that I can do? Write back is enabled on the controller for this array.
Regards,
Alex