A few words on replication. The standard replication is sending CCWS to all controller which have mirrors disks. Sometime controller send data to other controller to sync the data between all of them. In this process each controller emulates the CCWS and by that create the same data as the source disk. In this case the search key is very easy to implement.
MFNetDisk because of the slow media of TCP do something else. It is analyze the CCW in memory without accessing the source disk data. That is why it is hard to process the search key without access the data in the disk. After process the CCW it is decide what tracks need to be ReSync in the mirrors of the source disks. This process is complicate process especially for search key CCW. Using this processing, MFNetDisk never block the real disk but the minus is that this is ASync processing meaning that if there is crash in MF, the mirror may be not fully Sync with the source disk. the MFNetDisk replication can be good if you want to create Sync point or backup of the real disk in specific time where you can validate that the process of ReSync is done completely without updating the source disks for short time until the ReSync is totally over. This is called Sync Point where the mirrors is fully Sync with the real disk. About the MFNetDisk emulation. Each CCW is sent to the PC which access the data in the emulate disks and easily can process any CCW include serach key and all other CCWS. Shai On Sun, Oct 31, 2010 at 7:41 PM, shai hess <[email protected]> wrote: > Just to add. I talk about replication only where I try to figure out what > tracks of the mirrors need to be ReSync by MFNetDisk. > > > MFNetDisk support in the emulation all the CCWS which need to be supported > including all the search key types CCWS otherwise nothing was running. > > Shai > > > On Sun, Oct 31, 2010 at 7:32 PM, shai hess <[email protected]> wrote: > >> >> >> >>The fix also fixes some bugs processing non standard CCWS including >> search key CCWS and SHARK CCWS and many more. >> Sorry for the misunderstanding. The search key is hard to analyze the way >> I am do it. Because you can not be sure How to figure out the real track >> address which the key is adjust. >> When I talked about standard CCW I mean CCW which you can figure out the >> track address it is used. >> >> Shai >> >> > > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
