To be translated and elaborated

Vi skal passe meget på her med sikkerheden. Der skal være mulighed for, at det er benet der beder om data

Ved tab af større data mængder skal vi evt. også have mulighed for at to ben kommunikerer, evt. hvor klienten giver information om hvilket ben der skal bede om data fra hvilket andet ben.

Der skal også tages højde for at den nemmeste løsning kan være at en disk fysisk flyttes for at få overført data. Dette kan være samme scenarie som ovenfor, såfremt den "flytbare disk" kan identificere sig som det ben den transportere data fra.

En correction kan ske med en replace, eller kan være en delete efterfulgt af put. Delete-put afhænger dog af hvordan delete funktionen fungere (om den kan fortrydes) og der er et timing issue omkring afvikling af delete-put. Der er dog også et issue omkring fortrydelse når vi tager replace scenariet.

I testscenarier er der givet et scenarie for Replace file - pillar to pillar.
DENNE MANGLER KOMMINIKATIOSDELThe correct can either be in connection with

• lost data
• damaged data (action: replace damaged data)

For lost data the process must put the missing data to pillars that are missing the data. For damaged data the process must replace damaged data with correct data. After ended repair the integrity information must be updated, and possibly integrity checked. This is illustrated below.

Lost data

For loss of small data this is handled by put as illustrated in the figure. However for mass loss, we may have to open possibility for two pillars to communicate directly - though coordinated by client as for replacement.

There may also need to be cases where we need to physically move e.g. a disk from one pillar to another in order to make the data transfer of large chunks of data. It can be treated as the scenario for pillar to pillar communication, where moved data can be identified as the pillar it was transported from. however the full solution has to be both organisational and technical.

Damaged data

The actual replace operations is described in more detail under Replace File.