Speed problem loading ZFS partition

[serverguy]

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.

[b0ssman]

why are you opening up new post with the same problem but never replying with any request for additional information?

viewtopic.php?f=66&t=8168&p=49112#p49112

viewtopic.php?f=21&t=8283&p=49934#p49934

viewtopic.php?f=74&t=8294&p=50008#p50008

[serverguy]

I never get notified of any outstanding requests.

Feb 15 14:18:56 nas4tv smbd[43946]: unknown tag type 64
Feb 15 14:18:56 nas4tv smbd[43946]: [2015/02/15 14:18:56.631934, 0] ../source3/modules/vfs_posixacl.c:171(smb_ace_to_internal)
Feb 15 14:18:10 nas4tv smbd[43946]: unknown tag type 64
Feb 15 14:18:10 nas4tv smbd[43946]: [2015/02/15 14:18:10.677220, 0] ../source3/modules/vfs_posixacl.c:171(smb_ace_to_internal)
Feb 15 14:17:41 nas4tv smbd[43946]: unknown tag type 64
Feb 15 14:17:41 nas4tv smbd[43946]: [2015/02/15 14:17:41.563649, 0] ../source3/modules/vfs_posixacl.c:171(smb_ace_to_internal)
Feb 15 14:17:10 nas4tv smbd[43946]: unknown tag type 64
Feb 15 14:17:10 nas4tv smbd[43946]: [2015/02/15 14:17:10.812404, 0] ../source3/modules/vfs_posixacl.c:171(smb_ace_to_internal)

[b0ssman]

that seems to be a acl problem. what are your share configurations?

[serverguy]

Don't use ACL. Just doing some normal SMB sharing. One share on each partition. One user, maximum, ever.

I am not getting the type 64 messages at this time. Just frequent hangs of 3 to 18 seconds during playback. Per another thread, increased SMB buffer to 256,960.