From: geo@george.austin.ibm.com (George Noren)
Newsgroups: comp.unix.aix
Subject: Re: List of fixes in 3.2.3???
Date: 4 Nov 92 15:12:14 GMT
Organization: IBM AWD Early Systems Support

All good information in the following response about quorum, but please
note that it refers to a feature in "AIX Version 3.2.3 for RISC 
System/6000 Extended Support" which is the version that will be available
in December (12/25).  The version that is available now is 
"AIX Version 3.2.3 for RISC System/6000 Base".

Sincerely,
George Noren

+-----------------------+----------------------------------+-----------------+
| AIX                   | Inet: geo@austin.ibm.com         | PH: 512/838-4930|
| Technical Consulting  | VNET: GEORGE at AUSTIN           | TL: 678-4930    |
| IBM Austin - Zip 2830 | AIX : geo@austin.ibm.com         | FX: 512/838-4851|
+-----------------------+----------------------------------+-----------------+


In article <1992Nov4.094520.15590@awdprime.austin.ibm.com>, konopik@konopik.austin.ibm.com (Brad Konopik) writes:
|> In article <1992Oct29.104036@se05.wg2.waii.com> acker@se01.wg2.waii.com writes:
|> >
|> >3.2.3 is available now ... the X11R5 AixWindows is available in December ....
|> >
|> >I heard that 3.2.3 will now support booting of rootvg without quorum of the 
|> >VGDA (we mirror roovg over 2 disks instead of 3)...is this true?
|> >
|> >Douglas L.Acker                Western Geophysical Exploration Products
|> 
|> I pulled this from the announcement letter (292-532) off the anonymous ftp
|> machine Marc Prawlinger advertised a while back (IP address 192.35.233.1
|> in /pub/announcements after looking at 00INDEX):
|> 
|> NUMBER     292-532
|> DATE       920922
|> CATEGORY   GD00, GD70, WS00, AS60
|> TYPE       Programming
|> TITLE      IBM AIX VERSION 3.2.3 FOR RISC SYSTEM/6000
|>    :
|>  [stuff omitted]
|>    :
|>            o   Improved disk mirroring capability
|>                       AIX Version 3.2.3 for RISC System/6000 Extended Support
|>                allows the user to turn off Logical Volume Manager (LVM) quorum
|>                protection.  Quorum protection is designed to ensure data
|>                consistency and integrity.  When activating a logical volume
|>                group, the LVM reads management data from each physical volume
|>                defined in the volume group.  If the LVM cannot read a majority
|>                (quorum) of the copies of the management data, it will not
|>                activate a logical volume group.  However, if there are only two
|>                physical volumes in a volume group, losing one physical volume
|>                can cause the volume group to lose a majority of its management
|>                data areas (quorum) and thus prevent the volume group from being
|>                made available.  Turning off quorum protection allows a volume
|>                group to be available even when a quorum of its disks are not
|>                online.  For instance, this would make the alternate copy of data
|>                in a mirrored logical volume in a two-disk volume group
|>                accessible.  While this is a less expensive availability option,
|>                it is not as secure as running with LVM quorum on (which may
|>                require three disks to help guarantee no loss of data and no
|>                off-line time).  Users run the risk of data loss with quorum
|>                protection turned off, since the data may be accessible but not
|>                mirrored.
|> 
|> 
|> -- 
|>   tcpnet: konopik@konopik.austin.ibm.com  |  Brad Konopik
|>  ibmvnet: KONOPIK at AUSTIN               |  IBM AIX Porting Center, Austin
|> internet: konopik.austin.ibm.com!konopik@ibmpa.awdpa.ibm.com
|>    uunet: ..!uunet!ibmsupt!ibmpa!konopik.austin.ibm.com!konopik