"hardening" really means "confirmation" that the data has actually be written to permanent storage. Mumps code depends upon the GT.M run-time which depends on Linux which depends on the controller which depends on the disk drive. At each of those stages there can be -- and usually are -- buffers which hold data going to and fro. Bullet-proof transaction processing depends on KNOWING that the data it commits has actually been recorded -- not just sent out somewhere.
BTW, network-based storage systems have made this type of reliability another degree or two more difficult. ----- Original Message ----- From: "Nancy Anthracite" <[EMAIL PROTECTED]> To: <hardhats-members@lists.sourceforge.net> Sent: Tuesday, April 25, 2006 8:13 AM Subject: Re: [Hardhats-members] VMWare questions > Could you please expound a bit more on "hardening"? What is going on when > this happens, a rewrite of the data in exactly the same spot, perhaps? > > On Tuesday 25 April 2006 07:08, Bhaskar, KS wrote: > As far as GT.M is concerned, VMWare, Qemu, Windows virtual server, > Parallels, etc. are all equivalent. If it is a standard Linux, GT.M > will run on it. > > Running a production environment is yet another matter altogether. In > order to ensure recoverability, when GT.M issues a command to "harden" > the disks, it expects the data to be hardened to a permanent magnetic > medium. In a virtual machine, that "magnetic medium" is a file in a > host machine, which may or may not be hardened when the virtual machine > executes a sync operation to harden the data. I believe VMWare may be > the only one with an option to harden to the host magnetic medium. > > So, while virtual machines are excellent for demo and development > purposes, they are not suitable for production unless you can be assured > about hardening. > > -- Bhaskar > > > ------------------------------------------------------- > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > Hardhats-members mailing list > Hardhats-members@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/hardhats-members > > -- > Nancy Anthracite > > > ------------------------------------------------------- > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > Hardhats-members mailing list > Hardhats-members@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/hardhats-members ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid0709&bid&3057&dat1642 _______________________________________________ Hardhats-members mailing list Hardhats-members@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hardhats-members
