Re: [Libguestfs] [PATCH] p2v: Calculate offset of the Real Time Clock from UTC.

Calculate the offset of the physical host's Real Time Clock (RTC) from UTC and pass this to virt-v2v through the libvirt XML description of the physical machine. The libvirt XML is modified to add one of the following: (no <clock/> element) - if the RTC could not be read or there was some other time calculation error. <clock offset='utc' /> - if the RTC is the same as UTC. <clock offset='localtime' /> - if the RTC is in local time. It's not possible to distinguish between UTC and localtime in timezones that lie along the Greenwich Meridian (obviously including the UK), when daylight savings time is not in effect. In that case, UTC is chosen. Necessarily in timezones that use DST, this depends on when virt-p2v is run, so in the unusual case where a physical machine is switched off for a long time and then booted directly into virt-p2v when DST has changed, the calculation can be wrong. <clock offset='variable' basis='utc' adjustment='<seconds>' /> - if the RTC is some other offset to UTC, other than equal to UTC or localtime. ---