On Jul 7, 2008, at 3:46 AM, Robert Prus - Solution Architect, Systems Practice - Sun Poland wrote:
> > Hi, > > I have a set of questions regarding interaction of date(1) with > logical > domains. > > - Is LDOMS technology designed to set a separate system date/time > using > date(1) for every logical domain (i.e. control domain, service > domains, > guest domains)??? Of course setting different dates in different LDOMS > works, but my question is: is this working by design or by accident??? Each domain (regardless of roles such as control, service, etc) can have its date set independently. This is by design. > - How this change done in single logical domain interacts with other > logical domains (control domain, service domains, guest domains)??? There is no interaction; changing the date in one domain does not affect any other domain. > - Will this change be persistent across logical domain(s) halt/ > reboot??? The so-called Time of Day (TOD) offset generated as a result of issuing the "date" command is stored as a logical domain variable, and follows the same rules as other LDom variables in terms of persistence. The LDoms 1.0.3 release notes has a section that discusses LDom variable persistence, but in general, the change persists across the reboot of a domain. In addition, the TOD offset is stored as part of a domain's configuration when using the "add- spconfig" ldm subcommand to save the configuration of the currently active domains. > - Will this change be persistent across ILOM/ALOM reset/reboot??? Yes. > - Will this change be persistent across server power-cycle??? Yes, as long as the domain config is saved after changing the date as described above. > - Where information about date shift is stored??? - ILOM/ALOM??? It is stored with the other LDom variables in the hypervisor Machine Description (MD) for the running domain. When the add-spconfig ldm subcommand is issued, the entire configuration of a set of LDoms (including TOD offset) is further saved to the service processor for use on the next powercycle. > - How stable will be system date/time within logical domain? Do we > have > to expect significant date/time drift inside logical domain due to > sun4v > layer??? The date/time within a logical domain is no more or less stable than in a non-virtualized environment; the sun4v/hypervisor layer adds no extra instability. As always, drift is possible. It is perfectly acceptable to run a time synchronizing daemon such as ntp within your logical domains to avoid this. -Eric > > > Greetings and thanks in advance, > > Robert > > _______________________________________________ > ldoms-discuss mailing list > ldoms-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/ldoms-discuss -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 2425 bytes Desc: not available URL: <http://mail.opensolaris.org/pipermail/ldoms-discuss/attachments/20080707/13ce0034/attachment.bin>
