It was suggested to me that we should provide a way to return bytes read and written on block devices (not just requests). Xen doesn't support that however, so I have also changed the fields in this structure so that they can be returned set to -1 to indicate "no data / not supported". The updated stats structures are shown below. Rich. /* Block device stats for virDomainBlockStats. * * Hypervisors may return a field set to (int64_t)-1 which indicates * that the hypervisor does not support that statistic. */ struct _virDomainBlockStats { int64_t rd_req; int64_t rd_bytes; int64_t wr_req; int64_t wr_byes; int64_t errs; // In Xen this returns the mysterious 'oo_req'. }; typedef struct _virDomainBlockStats *virDomainBlockStatsPtr; /* Network interface stats for virDomainInterfaceStats. * * Hypervisors may return a field set to (int64_t)-1 which indicates * that the hypervisor does not support that statistic. */ struct _virDomainInterfaceStats { int64_t rx_bytes; int64_t rx_packets; int64_t rx_errs; int64_t rx_drop; int64_t tx_bytes; int64_t tx_packets; int64_t tx_errs; int64_t tx_drop; }; typedef struct _virDomainInterfaceStats *virDomainInterfaceStatsPtr; -- Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/ Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 03798903