[Libguestfs] Re: client-side LUKs + NBD over internet?

Would you mind sharing a little bit of information about your setup? Your local network setup appears to be performing much better than mine... I am using LUKSv2 (not the nbdkit LUKSv1 plugin) atop of an nbdfuse mount point on the client side. Below are some high-level, non-scientific observations for write speeds achieved while dd'ing /dev/zero to my target device from a client on a Gigabit LAN. nbdkit using 1G memory as the storage: * 810 MiB/s - LUKS + nbdfuse + nbdkit, w/ TLS (Not a typo, weird outlier result) * ~15 MiB/s - nbdfuse + nbdkit, w/ TLS * ~60 MiB/s - nbdfuse + nbdkit, no TLS nbdkit with a SW RAID5 device (HDDs attached via USB3-scsi controller): * ~1 MiB/s - LUKS + nbdfuse + nbdkit, w/ TLS * ~12 MiB/s - nbdfuse + nbdkit, w/ TLS * ~29 MiB/s - nbdfuse + nbdkit, no TLS Server-side dd /dev/zero directly to SW RAID5 target (HDDs attached via USB3-scsi controller): * ~64 MiB/s Both my client and server CPU and memory load seem quite low...almost negligible. The disk activity lights on the backing storage suggest to me that the disks are not being constantly written to. The disk appear idle for long chunks of time, followed by a short burst of activity. The disk write column in htop's IO tab shows a bunch of nbdkit threads with values ~50 K/s. Any thoughts welcome... trying to decide where to start focusing taking deeper measurements with and try some tuning. Thanks, Jon