- Use Case and Architecture assumptions as of now-
- Handling persistent page caches for VM images.
- VM images stored on network and client has hybrid NVRAM/DRAM memory.
- Possible Challenges-
- VM images may be modified when client system is off. eg- login from different machine, defragment, dedup(?).
- Similarly other challenges has to be figured out.
- Start Reading about page caches in LKD.
###2020-08-31
- Come up with a more detailed list of kernel/kvm excersizes which may be done. The list may keep on changing as move forward.
- Examples\-
- Implement some tool to demonstrate how KVM manages VM image file later point in time. (Read about this and come up with some excersize).
- To demonstrate page cache organisation, manipulation and updation.
- Come up with a description of problem we are working on. What all OS components would possible need modification.
###2020-09-7
- [@asgoyal] No progress on previous action items.
- [@asgoyal] Read about page cache in LKD and pmem.io book 2 chapters.
- [@puru] Come up with a summary of what you read if not anything on implementaion.
- [@puru] Revisit all action items of previous week.
- [@puru] Show some output on what you have done.
- Update the git repo with action items and meeting minutes.
- Next meeting on Thrusday(10th Sept.) at 12:30PM.
\ No newline at end of file
#MTP Meeting Minutes
###2020-09-14(Monday)
- Export symbol issue while trying to call a function defined in existing kernel module from a lodable module.
- Need to export symbol from the file which defines it, which would require kernel compilation.
- Instead could traverse the tasks list on your own.
- Write the problem description. may include- notes on each OS components affected, why is it intersting, related works in it, how would you test your solutions.
###2020-09-7(Monday)
- [@asgoyal] No progress on previous action items.
- [@asgoyal] Read about page cache in LKD and pmem.io book 2 chapters.
- [@puru] Come up with a summary of what you read if not anything on implementaion.
- [@puru] Revisit all action items of previous week.
- [@puru] Show some output on what you have done.
- Update the git repo with action items and meeting minutes.
- Next meeting on Thrusday(10th Sept.) at 12:30PM.
###2020-08-31(Monday)
- Come up with a more detailed list of kernel/kvm excersizes which may be done. The list may keep on changing as move forward.
- Examples\-
- Implement some tool to demonstrate how KVM manages VM image file later point in time. (Read about this and come up with some excersize).
- To demonstrate page cache organisation, manipulation and updation.
- Come up with a description of problem we are working on. What all OS components would possible need modification.
###2020-08-28(Friday)
- Use Case and Architecture assumptions as of now-
- Handling persistent page caches for VM images.
- VM images stored on network and client has hybrid NVRAM/DRAM memory.
- Possible Challenges-
- VM images may be modified when client system is off. eg- login from different machine, defragment, dedup(?).
- Similarly other challenges has to be figured out.
To make a kernel module which provides support for persisting page-cache objects. This module may bypass the the kernel page-cache management module to support mapping persistent page-cache objects. This may further be utilised by KVM to reduce the VM start time by directly utilising the persistent page caches in memory.
######OS components which may be impacted by this-
-**VFS layer**: This may meed VFS layer to maintain some versioning information to validate the page cache states. The file system metadata caches could also be persisted. This further needs some mechanisms for fault tolerance.
-**Physical FileSystem**: The physical filesystem may also need some minute changes to help VFS in validating the page-cache states.
-**Page-cache management**: Since, the page-caches are kept persistent, this also means that the faults(if occurs) would also be persistent. Also, half-update issue may arrise. So, there has to be some mechanism for ensuring page caches consistency at a suitable granularity of atomicity.
-**Virual memory**: The new virtual addresses has to be mapped correctly to the persistent physical page caches. This would further need mechanisms to ensure data security and other stuffs.
