[Sheepdog] issues about reading the source code
morita.kazutaka at lab.ntt.co.jp
Tue Mar 8 18:32:44 CET 2011
At Thu, 3 Mar 2011 14:26:44 +0800,
> I'm reading the source code of the sheepdog project, but thers are many
> terms that I can't understand.
> for example:
> epoch, obj , vdi, journal.....
Sorry, I really think we need more documents about the internal
implementation of Sheepdog.
- 'Epoch' means the version number of the node membership. When we
format the Sheepdog cluster, the epoch number is 1. If a new node
joins to the cluster after that, the epoch number will become 2.
- Sheepdog stores VM volumes by splitting them into 4 MB chunks. We
call the chunks 'object'.
- 'Vdi' is abbreviation of 'Virtual Disk Image'
- 'Journal' is used to keep vdi objects (metadata of VM volumes) in
consistent state even when Sheepdog crashes during write
> Do you have some documents that introduces the sheepdog architecture?
> I really want to learn the sheepdog code and contribute to it.
The slides I presented at KVM Forum 2010 could help you:
More information about the sheepdog