ZAR implements its own disk read and write caches to achieve better
performance. Read cache is used throughout the entire recovery run. Write cache
is only used during file copying process. The following guidelines apply:
- If recovering data from slow media (like ZIP disk or flash memory card),
increase read cache size. It would be nice if the whole media can fit into
the cache. If needed, decrease write cache size to the minimum to meet the
above total cache size requirement.
- If recovery destination is slow (e.g. when recovering to the network
drive), reverse logic applies - increase write cache size while sacrificing
read cache.
The above can be summariezed as use larger cache on slower side.
Factory settings are 16 MB for both read and write cache, tailored for
low-memory applications. Minimums are 16 MB for read and write cache.