Informix DB on SAN with SRDF
A user moved an Informix 11.x instance on RHEL 5 (2.6.18-128 PAE) onto an EMC VMAX SAN with SRDF replication. The vendor said the secondary copy should be inaccessible while SRDF is active, which held true on Solaris, but on Linux the secondary instance could be brought online and accept reads, writes and commits — although those changes disappeared after an instance restart, and splitting SRDF showed the primary's data. He asked why RHEL lets the secondary start, where the writes actually go, and whether a kernel patch was missing. Only a follow-up post giving the kernel version appeared; no answers or resolution are recorded in the thread.
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Hi all, We have moved our Informix Database ( 11.x on RHEL 5 ) to SAN VMAX and we have enabled SRDF on SAN. We were told by Vendor that when the SRDF is on, the secondary database will not be accessible. ( It is true on Sun Solaris platform and we have checked ). But in RHEL 5, when SRDF is on we are able to bring Secondary Database online and work on the Database ( Read/Write/Commit). Even though the Secondary database allows to do Write/Commit, when we restart the Secondary Informix instance all changes in Secondary vanishes. When we split the SRDF we are able to see the Primary Database server contents. Question 1. Why does RHEL allow to start the Informix Instance. ( In solaris this does not happen as the Informix instance does not come up ). Question 2. Where does the writes/commits go, when Secondary Server is started. ( SRDF is on ). Can RHEL 5.0 do the same way as Solaris ( not allow the secondary if SRDF is on ). Are we missing any Kernel patches. We are in the RHEL Kernel release xx.xx.x.153 Please advise .. Thanks Dhaya
On Jan 7, 10:33 pm, sdhaya <dhaya.sni...@gmail.com> wrote: > Hi all, > > We have moved our Informix Database ( 11.x on RHEL 5 ) to SAN VMAX > and we have enabled SRDF on SAN. We were told by Vendor that when the > SRDF is on, the secondary database will not be accessible. ( It is > true on Sun Solaris platform and we have checked ). But in RHEL 5, > when SRDF is on we are able to bring Secondary Database online and > work on the Database ( Read/Write/Commit). > > Even though the Secondary database allows to do Write/Commit, when we > restart the Secondary Informix instance all changes in Secondary > vanishes. > > When we split the SRDF we are able to see the Primary Database server > contents. > > Question 1. Why does RHEL allow to start the Informix Instance. ( In > solaris this does not happen as the Informix instance does not come > up ). > > Question 2. Where does the writes/commits go, when Secondary Server is > started. ( SRDF is on ). > > Can RHEL 5.0 do the same way as Solaris ( not allow the secondary if > SRDF is on ). Are we missing any Kernel patches. > > We are in the RHEL Kernel release xx.xx.x.153 > > Please advise .. > > Thanks > > Dhaya Our version of RHEL is 2.6.18-128.1.1.el5PAE #1 SMP