New LV 4K offset problem under AIX

Problem phenomenon:

Create a new LV on AIX and then create a table space on the LV, appearing warning (Oracle recommends creating new datafiles on devices with zero offset)

Alter tablespace zj_data add datafile '/dev/rdata40_disk ' size 2500M

Wed APR 27 22:45:36 2011

Warning:you are creating Datafile/dev/rdata41_disk.

Warning:oracle recommends creating new datafiles on devices with zero offset. The command "/usr/sbin/mklv-y lvname-t o-w N-S n-r vgname Numpps" can be used. Please contact Oracle Customer support for more details.

After Mklv-t o-y Data40_disk oradatavg 1 reconstruction of the above table space after the warning disappears, run for a period of time the database is completely normal, the visible data file has been written to the normal datafile.

But accidentally once LSLV compared the database online and just built two LV files, found in type, Devicesubtype, relocatable, MIRROR WRITE consistency, each LP COPY on A separate PV

There are differences, as detailed below.

$ LSLV Data40_disk

LOGICAL Volume:data40_disk VOLUME Group:oradatavg

LV identifier:00c164fe00004c0000000110a1021713.66 Permission:read/write

VG State:active/complete LV STATE:OPENED/SYNCD

TYPE:JFS WRITE Verify:off

MAX lps:512 PP size:256 megabyte (s)

Copies:1 SCHED Policy:parallel

Lps:10 pps:10

Stale pps:0 BB policy:relocatable

Inter-policy:minimum Relocatable:yes

Intra-policy:middle UPPER bound:16

MOUNT point:n/a Label:none

MIRROR WRITE consistency:on/active

Each LP COPY on A separate PV?: Yes

Serialize IO?: NO

Devicesubtype:ds_lvz

$ LSLV Data_disk

LOGICAL Volume:data_disk VOLUME Group:oradatavg

LV identifier:00c164fe00004c0000000110a1021713.14 Permission:read/write

VG State:active/complete LV STATE:CLOSED/SYNCD

Type:raw WRITE Verify:off

MAX lps:512 PP size:256 megabyte (s)

Copies:1 SCHED Policy:parallel

Lps:4 pps:4

Stale pps:0 BB policy:relocatable

Inter-policy:minimum Relocatable:no

Intra-policy:middle UPPER bound:16

MOUNT point:n/a Label:none

MIRROR WRITE Consistency:off

Each LP COPY on A separate PV?: No

Serialize IO?: NO

To identify the default parameters for the MKLV command, let's continue with a few tests