Speed problem loading ZFS partition
Posted: 15 Feb 2015 05:00
This N4F machine has high capabilities. Quad Athlon and 8GB of memory. So there are no obvious constraints. The network easily hits 600Mb/s but drops to idle for about half the time.
While loading large files onto a ZFS partition, the network throughput is intermittent. This is not a slowdown caused by many small files causing head thrashing but during large file writing, over and over.
See attachment to see how the CPU is just sitting around and so is the network. Something is holding up the transfer. The only thing I have left in my idea list is that ZFS is screwing around waiting for something or doing something that keeps it from being able to take more data.
The source device is easily capable of continuous 600Mb/s transfers and has proven that capability over and over, even while writing. In this situation, I am reading from it and loading to N4F ZFS partition. It is RaidZ1 with 4x4TB drives.
So where is the problem? I cannot isolate any reason why this will happen. I am beginning to be sorry I switched off of my Synology units to this mess. It is exceptionally slow delivering directory listings across SMB, VERY slow writing data and moderately slow delivering video with occasional stutters.
While loading large files onto a ZFS partition, the network throughput is intermittent. This is not a slowdown caused by many small files causing head thrashing but during large file writing, over and over.
See attachment to see how the CPU is just sitting around and so is the network. Something is holding up the transfer. The only thing I have left in my idea list is that ZFS is screwing around waiting for something or doing something that keeps it from being able to take more data.
The source device is easily capable of continuous 600Mb/s transfers and has proven that capability over and over, even while writing. In this situation, I am reading from it and loading to N4F ZFS partition. It is RaidZ1 with 4x4TB drives.
So where is the problem? I cannot isolate any reason why this will happen. I am beginning to be sorry I switched off of my Synology units to this mess. It is exceptionally slow delivering directory listings across SMB, VERY slow writing data and moderately slow delivering video with occasional stutters.