Maximum Physical Partition and filesystem size, PP's in LV
Env: 3.2.5 and 4.1
Desc: Customer wanted to know the maximum Physical Partition
size, maximum number of Physical Partitions per Logical
volume and maximum filesystem size under AIX 3.2.5
and AIX 4.1
PP size 256MB 256MB
PP's in LV (see note)
Filesystem size 2 GB 64 GB
AIX 3.2.5 used 32 bit signed integers for addressing
AIX 4.1 uses 64 bit long long variables for addressing
The limits on PP is actually a hard coded limit due to the
fact that integers are used to represent this field. The actual
limit that can be allocated is 32512 PP's per LV. This is found
by knowing that we can have 32 PV's per VG and since one LV can
span the entire VG and you can have max of 1016 PP's per PV.
32 Pv/VG * 1VG/1LV * 1016 PP/PV = 32512 PP/LV
But since AIX can only address 2GB filesystems under 3.2.5 or 4Gb
filesystems under 4.1 these logical volumes would have to be
accessed as raw logical volumes.
Also, this would allow a maximum of 8.52e+12 bytes in one VG.
32 PV/VG * 1016 PP/PV * 256MB/PP = 8.522e+12 MB
Filesystem limits for AIX 4.1: All About AIX 4.1 pg 91
LVM_MAXPPS Max \# of PP's
LVM_MAXLPS Max \# of LP's
LVM_MAXPVS Max \# of PV's
Support Line: Maximum Physical Partition and filesystem size, PP's in LV ITEM: AC5980L
Dated: April 1997 Category: N/A
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