MAX PVs only 10 2

[rondebbs]

I was surprised when I looked at the VG below. I need to add several new volumes but noticed that the MAX PVs is only 10. Since it is not 32, I'm guessing that someone made some type of change to the VG and this caused the MAX PVs to reduce to 10. Does this sound correct? Is there anyway I can increase this number?

VOLUME GROUP: isd2vg VG IDENTIFIER: 00008aa20000d70000000116426e9d9b
VG STATE: active PP SIZE: 64 megabyte(s)
VG PERMISSION: read/write TOTAL PPs: 2187 (139968 megabytes)
MAX LVs: 256 FREE PPs: 586 (37504 megabytes)
LVs: 3 USED PPs: 1601 (102464 megabytes)
OPEN LVs: 3 QUORUM: 2
TOTAL PVs: 1 VG DESCRIPTORS: 2
STALE PVs: 0 STALE PPs: 0
ACTIVE PVs: 1 AUTO ON: yes
MAX PPs per VG: 30480
MAX PPs per PV: 3048 MAX PVs: 10
LTG size (Dynamic): 256 kilobyte(s) AUTO SYNC: no
HOT SPARE: no BB POLICY: relocatable

 

[cspilman]

Looks as though someone changed the limit of the number of physical partitions per physical volume by changing the factor value using chvg -t.

I know you can increase but haven't ever needed to decrease the value. I'll have to check the man pages on chvg to tell for sure.

Maybe someone else can verify this for you?

Regards,
Chuck

 

[khalidaaa]

Chuck is correct! you have to change this back using the chvg -t!

http://www.tek-tips.com/viewthread.cfm?qid=993416&page=1

Regards,
Khalid

 

[khalidaaa]

And this is the man page for chvg:

http://publib.boulder.ibm.com/infoc...topic=/com.ibm.aix.cmds/doc/aixcmds1/chvg.htm

-t [factor] Changes the limit of the number of physical partitions per physical volume, specified by factor. factor should be between 1 and 16 for 32 disk volume groups and 1 and 64 for 128 disk volume groups. 
If factor is not supplied, it is set to the lowest value such that the number of physical partitions of the largest disk in volume group is less than factor x 1016.

If factor is specified, the maximum number of physical partitions per physical volume for this volume group changes to factor x 1016.

Notes:
This option is ignored for Scalable-type volume groups. 
If the volume group is created in AIX 4.1.2 in violation of 1016 physical partitions per physical volume limit, this flag can be used to convert the volume group to a supported state. This will ensure proper stale/fresh marking of partitions. 
factor cannot be changed if there are any stale physical partitions in the volume group. 
Once volume group is converted, it cannot be imported into AIX 4.3 or lower versions. 
This flag cannot be used if the volume group is varied on in concurrent mode. 
The maximum number of physical volumes that can be included in this volume group will be reduced to (MAXPVS/factor).

Regards,
Khalid

 

[costiles]

However - changing this factor - the t factor will result in a larger pp size. That may effect your distribution of data on the disks. For instance - if you are using the intra-policy of maximum - and you have files smaller than 64 mbs - they will be on only 1 disk. I suspect that the person who made the change was trying to get a smaller pp size in order to spread the load on a particular file over multiple disks.

 

[MoreFeo]

I think the PP size can only be set at creation time, it cannot be changed. What you change with the t factor is only the max PPs per PV, not the PP size (I think).