Hi, > On 23 May 2023, at 19:45, Poul-Henning Kamp <[email protected]> wrote: > > >> 1. BHYVE SNAPSHOT image format: > > Please do not invent Yet Another Format, please ? > > Why not make it a tar(5) file ? >
Tar cannot solve issues mentioned in “disadvantages”. Tar doesn’t have versions, it is just container for files that would introduce another level of indirection. Snapshot/resume doesn’t need just container. It needs information what is saved and in what format. For example, virtual memory can be saved in different ways: binary, diff pages, etc. Virtual memory of VM should be saved faster without additional cost. The same for restore stage. Do you like an idea to have tar file with size 8 GB ? And how it can be saved efficiently without double copying of data? Yes, tar is powerful and convenient for many purposes, but it is not so suitable to suspend/resume process and would introduce just another level of complexity. —— Vitaliy Gusev
