On 13/10/14, 21:16, Peter wrote: > On 10/14/2014 02:15 PM, Joakim Ziegler wrote: >> I have a rather large box (2x8-core Xeon, 96GB RAM) where I have a >> couple of disk arrays connected on an Areca controller. I just added a >> new external array, 8 3TB drives in RAID5, and the testing I'm doing >> right now is on this array, but this seems to be a problem on this >> machine in general, on all file systems (even, possibly, NFS, but I'm >> not sure about that one yet). > The first thing I would check is that you have a BBU installed on the > areca controller and that it is functioning properly (check the cli, I > don't know the exact commands off the top of my head), also make sure > that write caching is enabled on the controller (after you've checked > the BBU, of course). Without a working BBU in place hardware RAID > controllers, such as areca, disable write caching (by default) and this > will have a significant impact on write speeds. > Note that newer controllers use a type of flash memory instead of a BBU. Yes, I have a BBU and it's working. No write caching should, however, not affect raw device writes and filesystem writes so differently, I think. -- Joakim Ziegler - Supervisor de postproducción - Terminal joakim at terminalmx.com - 044 55 2971 8514 - 5264 0864