I need to migrate Informix database version 5 from a HP Alphaserver running on Tru64 Unix to a new machine.
The db size is around 1.5TB. There is no DBA tool installed and there is no more disk space on the server to store any export file.
I have done a disk imgae copy using the dd command. This supposedly copies all the data, but after importing to the new server, I discovered some data are "missing". The table is copied, no doubt, but the data is incomplete (lesser than the source). Why is this so?
I need an expert to help to resolve this issue.
I am willing to pay for the service.
That Informix version is really old
I suppose you are talking about Informix OnLine 5.x, which is unsupported version for a long time. You maybe want to migrate to IDS 11.5x or upper version. If it so, please look into this link, maybe it would help You:
However you will need to use a basic command line utilities that comes with that version and be a little patient because that is a lot of data to migrate.
You didn't specify if the data is stored on disk using a RAW device or a cooked files. Suppose as you tried to use a dd command the data was on file-system, but with that amount of data and usually that isn't advised on that version, only @IDS 11.10 using DIRECT_IO on OS supported, so I don't know...
As you experienced the dd OS command is nice to copy a simple structure files, but it doesn't work as it was expected in this case.
maybe you could specify to which version on which platform you want to migrate to.
Or do you want to keep version and OS the same, just migrate to another machine?
In the latter case, dd should work, but the layout / links on the target machine need to be identical.
If not (version and OS changed), dd is not a supported migration method and would not work as the internal Informix structure changed considerably in the meantime - an intermediate upgrade via version 7 would be needed, as in Luis' link.
So it would be best to find a harddrive on which to dbexport the database(s) to and dbimport
them to the new system using the same environment. Problem is, dbex-/importing 1,5 TB would take a long time (days, probably) as all the data is ex-/imported consecutively.
You could try using HPL or external tables to speed things up, though, but this requires an update
to a newer version.
Forget about HPL, it has been introduced in 7.X as far as I remember.
dd is supported in NO WAY if the target version is different and the target hardware is different: we need more details on the target machine and the version you want to install in it.
Remaining in version 5 is definitaly not a good idea. You are totally out of support, which is never good for a production environment.
Go to version 12.10, you will love it.
Now for the migration itself, several paths are possible, as mentioned above:
1) intermediate to 7.31, then you could even imagine a INSERT INTO dbname:tablename@target_instance SELECT * FROM sourcetable ( crazy but it should work if both dbs are in no log)
2) set a shared filesystem between both machines, unload to it from source db and load from it into taget db
I have tools that should work for solution #2 ( i should test them with onlien 5.0 but should work). The host system must have perl as a requirement.
What is you time schedule and where are you based ?