Re: IDS 11.5 and SDS

On Jan 28, 3:11 pm, Madison Pruet <mpru...@verizon.net> wrote: > Madison Pruet wrote: > > Tom wrote: > >> Greetings All, > > >> Has anyone configured IDS 11.5 with SDS on any AIX platforms? I am > >> configuring two new servers and plan on using IDS 11.5 features for HA > >> and it looks like a Shared Disk Secondary would fit the bill. However, > >> a call to IBM Informix as well as IBM AIX Software group provided no > >> info on how to configure AIX using raw LV's to meet the "Shared" disk > >> requirement for SDS to work. > > >> The two servers are identical P6-550's connected via SAN to an IBM > >> 2105-800. The IDS is 11.5.FC3. > > >> Thanks, > > >> Tom > > > Tom, > > > The only real requirement is that the shared disk subsystem ensure that > > when the server issues a write IO that the write makes it all the way to > > the physical disk before returning a write complete status. > > and that the read comes from the physical disk and not from OS/disk > memory buffers. In other words, if node A writes a page and node B > subsequently reads that same page, then node B must read what A wrote... > > We can not > > > support any form of shared disk environment in which the write remains > > in a buffer - be it OS or disk cache - and then is trickle written to > > the disk. There is a bit of coordination between the disk writes and > > the SDS nodes which must be supported. > > > The information that you are getting from tech support is based on what > > we have tested with, but we do have some customers who have either > > tested or are in production with shared disk solutions outside of what > > we tested with internally. > > > M.P. So is raw a better option because the OS doesn't get in the way? Or are you OK just turning on DIRECT_IO and using a global file system?