Re: switch from file system to raw device

Servus Anton,

> i did some Oracle on AIX with Oracle 6.x and 7.x in 1992-1995.
I started with 6.x on HP in 1992, using 7.x from 94-now (Digital and AIX), started with 8.0.x in 1999.

> I had the official statement from IBM that raw devices with this
> configuration is -slower- than filesystem use.
I don't argue this, and maybe our tests were too much "hand made" to be real test cases. And sometimes official statements are political choices.

> Reason might be far better caching of jfs/fs versus Oracle.
Maybe you just don't want something to be cached?

> Dealing with raw devices is non trivial.
As I said in another comment this morning, I guess, it's just a question of personal preference and experience. Don't get me wrong, I am not saying, someone is not a good sysadmin/dba if he can't handle raw devices, I just made experience on raw device, my tests said to prefer raw devices and I just got used to it (Digital, AIX, Linux).

> Put your resources into an supported Version of Oracle, probably 10g.
As I said before, some statements (or decisions) sometimes are political choices. In our case, we have in particular two systems, billing and SAP, that -your are right, are running on unsupported platforms- are not to be changed at this moment. We have compatibility statements for this combination of OS/Application/DB and no one is going to take any responsibilities to change one component, as manufacturer of the Application won't "just fix" eventual problems. So we are damned to stick to this combination until "the big bosses" decide to go onto a new Application, New Platform, New DB and so on and to pay $$$ for it. It's not the sysadmin's decision which piece to change, do you agree? I would update/upgrade but what if things won't run any more as they used to? I have family, you know ... ;-)

> I bet a fast AMD/Intel box with SLES9/kernel 2.6 and Oracle 10g is far
> cheaper/faster than changing your setup.
I bet that's again just a point of view and a decision. We use Linux/Intel systems for auxilary systems, like test or some kind of monthly reporting systems, that are copies of production systems. No one will ever decide, at least in my company, to adapt Intel/Linux for production if there is no clear compatibility statement, if there is no support statement, and, I guess, in a large company (like IBM), they might not be more clever that others (like SUSE), but there are more of them and at the end, someone will have an idea or experience ... what do you think?

And, sorry, I just don't get the point about cheaper (faster maybe, but cheaper)? At this point, I actually have a running system and have some disk space for the second copy. I can do the switch with no additional cost if not my working time (if things are possible and if things go well). Even if Intel/SLES and whatever is faster, you just have to buy it. The Intel costs something, the SLES for professional, but more than all, the 10g does $$$ something. Don't you think?

Thanks a lot and best regards,
Igor Received on Thu Sep 16 2004 - 02:11:23 CDT