[pbs-devel] [PATCH 0/3] Add cache for live-restore

Stefan Reiter s.reiter at proxmox.com
Wed Apr 28 18:06:52 CEST 2021


Adds a mmap-backed buffer (as suggested by Dietmar to avoid memory starvation)
of 64+256 MiB for accessing chunks from PBS. Helps to accelerate live-restore.

Quantitative benchmarking appears really hard, variance between live-restore
runs is really high for some reason (both time-to-desktop and time-to-finish).
On average it seems to be between equal and up to 30% faster - again, with a lot
of variance between runs.

In testing with a Windows VM I saw cache hit rates of about 25% or higher, so
the cache is certainly used, but there seem to be too many other factors in
play...


proxmox-backup: Stefan Reiter (2):
  tools: add mmap_buffer module
  RemoteChunkReader: add LRU cached variant

 src/bin/proxmox_backup_client/mount.rs |  12 ++-
 src/client/remote_chunk_reader.rs      | 110 ++++++++++++++++++++----
 src/tools.rs                           |   1 +
 src/tools/mmap_buffer.rs               | 113 +++++++++++++++++++++++++
 4 files changed, 218 insertions(+), 18 deletions(-)
 create mode 100644 src/tools/mmap_buffer.rs

proxmox-backup-qemu: Stefan Reiter (1):
  access: use bigger cache and LRU chunk reader

 src/restore.rs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

-- 
2.20.1





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