[Oracleasm-support-devel] Disk scanning updates - testers wanted.

[Joel Becker]

Hi Everyone,
	As some of you may have noticed, oracleasm-support scans the
disks on your system based on the information provided in
/proc/partitions.  This used to be the only way to determine what disks
actually existed in the system.
	This causes a couple of limitations.  First, scanning matches
the names in /proc/partitions, not necessarily the names used when
labeling an ASM disk.  This can be confusing when a disk was labeled
using the /dev/disk/by-id/... name, but it is scanned by the /dev/dm-...
name.  Furthermore, some udev configurations don't even provide
/dev/dm-... names anymore.  Second, some devices appear in sysfs only,
making /proc/partitions no longer the only repository of this
information.
	I've just reworked the disk scan code to look in /sys/block,
/proc/partitions, and /dev to build its list of block devices.  This
provides the following benefits:

- SCANORDER and SCANEXCLUDE directives can match both kernel names
  (/proc/parititions) and udev names (any name for the device in /dev).
- udev reordering of the kernel-style names is now supported.  Before,
  if /proc/partitions called a disk sdd, but udev renamed it /dev/sde,
  the scan might not complete correctly.  The new code should handle
  this case, because it matches all /dev names to the device number.
- Systems that don't provide /dev/dm-... names in their default
  configuration should work out of the box.

	I'm emailing the lists because I'm looking for testers.  I'm
sure this is going to break for somebody, somewhere, and I want to
figure out if I got something wrong before I ship it.  We will, as
always, test this for release inside Oracle.  But the world is full of
far more varied configurations than we can test, and I want to see if
the community here can help me shake this code down.
	To that end, I've put up some beta RPMs on oss.oracle.com.
These are first cut - they are tested on a couple of systems, but are
not production ready.  If you have some non-essential or demo systems,
please slap them on and test them out.  If you do want to test them on
semi-production systems, they shouldn't break anything; they're only
listing the system disks in a different way.  But if they have trouble
discovering all your disks, please go back to the production releases -
after reporting the problem, of course!
	Test packages of oracleasm-support for EL4 and EL5 on x86 and
x86_64 are available at
http://oss.oracle.com/~jlbec/files/oracleasm/test/.  The 2.0.0-0 version
number is just for testing - the final version with these changes has
yet to be determined.
	Thank you all in advance.

Joel

PS: as an added bonus, the SCANORDER and SCANEXCLUDE patterns can be
configured to use regular expressions instead of prefix matching.
Prefix matching remains the default, but you can use 'oracleasm
configure' in the advanced mode to switch to regular expressions.

-- 

"Behind every successful man there's a lot of unsuccessful years."
        - Bob Brown

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127