Don't use ASMLib. Use UDEV rules instead.
I implemented it on Linux 6 and 7 with Oracle 12c and it works perfect!
Deploying Oracle RAC Database 12c on Red Enterprise Linux 7:
I would recommend you to use asmfd.
The greatest advantage with it is ASMFD rejects write I/O requests that are not issued by Oracle software. So even the sysadmin won't able to corrupt the header.
Thanks all for your feedback.
ASMFD: that is an appropriate consideration point. For a new system should we be using ASMFD as the best ROI? Oracle docs seems to indicate so.
Is anyone using ASMFD for production environments at this point?
Yes, we are using ASMFD, but it was not so simple to implement it from the scratch. We had to deal with some bugs (some are solved already), but at the end it works well.
Which bugs do you mean (one example)? Where they fixed with patches or workarounds? For our new project I want to use ASM Filter Driver up from beginning.
I think I'll start investigating ASMFD. Udev is well documented and supported.
Being a bit of an ASM newbie, I'd like to still be clear on one thing please. If one uses ASMLib do you still need to manually the configure 90-ib.rules and the like or does ASMLib functionally take care of this?
Just follow the guide in the document for which I provided you the link in the post above.
Here are some additional articles I used earlier:
AFD - ASM Filter Driver:
ASMFD : How to Migrate ASM Diskgroups from ASMLIB to ASMFD (ASM Filter Driver) on Oracle Grid Infrastructure (RAC) (Doc ID 2172754.1)
regarding your given reference to Oracle RAC 12c Database on Linux Using VirtualBox in Section "Create ASMLib Disk", there is a short note "Please skip the next section "Udev Configuration".
However I've some tests performed with AFD Filter Driver and ASMLib for future usage, I never had to create UDev rules.
My major intention is, to keep it possible simple adding disks to ASM in future production env. There are so many other thinks to consider arround RAC, multitenat, backup, database, patching.., that I don't want dangling with udev-rules.
I think ASM Filter Driver is very usefull avoiding accidentally overwrite a ASM disk (what a nightmare) and is easy to handle. Maybe ASMLib will become deprecated and we have to migrate to AFD, regarding to that we will use AFD.
At least, some blogs are very helpfully for me (thanks to all DBA Bloggers for sharing there knowledges), but meanwhile I do not believe everything from there.
Yes,controlling the unauthorized write to the asm devices is an awsome feature of asmfd.
A lot of the asm corrutions are related to overwrite issue.