> Hello, > Yes, I'd like to have timeshift by some number of > seconds, why ? > The main reason is that developers need to know how > software will run in > particular time (end of month, end of year). So they > can write and test > new software. > I know, there are other way to test software, but > this is, I think, most > easy way and there is no impact to this software. > Containers are very good for such environments > (test&developer) so > timeshift it's, I think, important.
Maybe changes could be made to make that possible, but except for testing timezone or Y2K/Y2038/whatever transition issues, it might actually be a bad thing - more overhead for system calls that need to be fast, more opportunities for people to do something Really Stupid, and that code would probably get exercised less that would be the case with the code that leaves the time alone in the non-global zones, so it would tend to have problems not be discovered/fixed so quickly. I would suppose there would always be some ways in which a zone was less flexible (esp. for certain types of testing) than a separate OS instance. If a zone could do _everything_ a separate OS instance could do, it would be no lighter weight, no more efficient, than a virtualized OS instance. OTOH, a zone is quicker to set up, and can divide resources finer than either hardware domains or LDOMs. If it weren't that you were running on SPARC, I'd say that virtualization via xen or the like would be your best bet. Maybe that will exist there one day, but AFAIK it doesn't now... For most (esp. in Solaris 10 and later, given that static linking is no longer supported) software, one could create an LD_PRELOADable wrapper for various calls that deal with times that allows an environment variable to contain an offset for them. I did that just for the heck of it for Y2K testing, although I don't think anyone used it. I even posted it on Usenet, and if you looked you could find it, although I've done that for you: http://groups.google.com/group/comp.unix.programmer/msg/e2e19c170232611c?dmode=source&output=gplain The only problem is that you need to have the same setting of that environment variable for all processes that need to have a consistent view of the time via the functions that are wrapped (not to mention whether you want to also offset stuff like file timestamps and so on). Still, I suppose there are other examples of that sort of thing available if you scrounge a little...maybe one of them would do the trick for you. This message posted from opensolaris.org
