Re: Aix Mirroring Vs Informix Mirroring

In article <C7BIIp.7r7@newsserver.technet.sg>, scornd7@technet.sg (Tang Chang Thai) writes: |> At my site, we are using hardware mirroring for HP workstations. It also |> works transparently. |> |> Ellen K. Osinski (ellen@hpbs2571.boi.hp.com) wrote: |> : > In general, operating system level mirroring and hardware mirroring are |> : > more efficient than Informix mirroring, if only because they can schedule |> : > writes to both the primary and the mirror disk concurrently, whereas |> : > Informix has to write to the primary and then write to the mirror. |> : > |> : > When you don't have lower level mirroring, use Informix mirroring, but use |> : > a lower level mirroring system if you have a choice. These rules apply to |> : > version 4 or 5 -- they may need to be reconsidered with version 6, though I |> : > doubt it. |> : > |> : > Yours, |> : > Jonathan Leffler (johnl@obelix.informix.com) #include <disclaimer.h> |> : > |> |> : I can put in a plug for Informix mirroring. We have implemented mirroring |> : on an HP9000/750. We had the primary go down due to repeated disk write |> : failures and did not realize it for a day or two. Informix chugged merrily |> : along quite happliy using the mirror completely transparent to the users. |> |> : Would hardware mirroring provide this transparency? |> It is my understanding that in 6.0 Online with do reads from both the primary AND the mirror. Of course this will only work if Online knows about the mirror...so I think that at least under 6.0 Informix mirroring would be a better (?) choice. -- ------------------------------------------------------------------------------- Mike Reetz boulder.colorado.edu!morse!reetz UNIX(tm) Operations Manager or reetz@ncar.ucar.edu (<== BEST) UCAR - University Corporation For Atmospheric Research