You do not need to reconfigure log storage for ESXi hosts that use the default configuration, which stores logs in a scratch directory on the VMFS volume. For these hosts, ESXi 5.0 auto configures logs to best suit your installation, and provides enough space to accommodate log messages.
If your host is deployed with Auto Deploy, reconfigure your log storage in one of the following ways:
Redirect logs over the network to a remote collector.
Redirect logs to a NAS or NFS store.
You might also want to reconfigure log sizing and rotations for hosts that are installed to disk, if you redirect logs to non-default storage, such as a NAS or NFS store.