[Libguestfs] [PATCH v3 0/7] v2v: rhv-upload-plugin: Performance improvments

Update the plugin to API_VERSION 2, and enable parallel threading model. With unordered writes in qemu-img, and 8 threads in nbdkit, matching number of parallel coroutines in qemu-img, I see about 50% speedup compared with current master. I tested this on a vm, using NFS storage provided by another vm, and accessing ovirt-engine on a third vm. Results are not stable, and can vary by 100% between runs. I'm comparing the best result from 3-5 runs. We need to test these changes with real images, real servers, and real storage to get more reliable results, but I could not find avilable server yet. Changes since v2: - Add plugin#write_out_order method and use it to enable out of order writes (-W) in the rhv upload plugin. - Update the commit message about fua and flush support, based on the discussion with Eric. - Fix more typos in comments v2 was here: https://www.redhat.com/archives/libguestfs/2021-January/msg00067.html Nir Soffer (7): v2v: output_rhv_upload: Require nbdkit >= 1.22 v2v: rhv-upload-plugin: Use API_VERSION 2 v2v: rhv-upload-plugin: Support FUA v2v: rhv-upload-plugin: Get imageio connections limits v2v: rhv-upload-plugin: Support multiple connections v2v: rhv-upload: Use out of order writes v2v: rvh-upload: Match nbdkit threads to qemu-img coroutines v2v/nbdkit.ml | 4 + v2v/nbdkit.mli | 1 + v2v/output_rhv_upload.ml | 13 +- v2v/rhv-upload-plugin.py | 318 +++++++++++++++++++++++++++------------ v2v/types.ml | 1 + v2v/types.mli | 2 + v2v/v2v.ml | 1 + 7 files changed, 238 insertions(+), 102 deletions(-) -- 2.26.2