0516-787 extendlv: Maximum allocation for logical volume error

Sometimes you will see this error when you want to extend filesystem / logical volume.

Error Message:  0516-787 extendlv: Maximum allocation for logical volume <LV_Name> is 512.
Maximum number of LPs for the logical volume has been exceeded – must increase the allocation

It indicates that your LP allocation is insufficient, hence it needs to be increased. Maximum LP value can be increased on-the-fly without unmounting the LV first.

Case study.

I’m trying to increase additional 300GB to my SAP backup directory but failed with 0516-787 error.

sappr08(DMP)# chfs -a size=+300G /sapdb/DMP/backup
0516-787 extendlv: Maximum allocation for logical volume lvDMPbackup
is 5120.

Use “lslv lvDMPbackup” to verify max LPs value for your logical volume.

sappr08(DMP)# lslv lvDMPbackup
LOGICAL VOLUME:     lvDMPbackup            VOLUME GROUP:   sdbdmpvg
LV IDENTIFIER:      00f60f5200004c000000012abb2ed482.9 PERMISSION:     read/write
VG STATE:           active/complete        LV STATE:       opened/syncd
TYPE:               jfs2                   WRITE VERIFY:   off
MAX LPs:            5120                   PP SIZE:        256 megabyte(s)
COPIES:             1                      SCHED POLICY:   parallel
LPs:                4594                   PPs:            4594
STALE PPs:          0                      BB POLICY:      relocatable
INTER-POLICY:       minimum                RELOCATABLE:    yes
INTRA-POLICY:       middle                 UPPER BOUND:    1024
MOUNT POINT:        /sapdb/DMP/backup      LABEL:          /sapdb/DMP/backup
MIRROR WRITE CONSISTENCY: on/ACTIVE
EACH LP COPY ON A SEPARATE PV ?: no
Serialize IO ?:     NO

Now what we need is to increase LP allocation for your logical volume. You can calculate how many LP needed before we can expand the filesystem successfully.

Formula: LV Size in MB / LP size in MB

How to calculate LP value.

1. Get your LV size in MB. Use df -m <filesystem>

sappr08(DMP)# df -m /sapdb/DMP/backup
Filesystem    MB blocks      Free %Used    Iused %Iused Mounted on
/dev/lvDMPbackup 1483264.00 511005.14   66%     4690     1% /sapdb/DMP/backup
sappr08(DMP)#

So, LV size = 1483264 MB

2. Get  PP size from your LV

sappr08(DMP)# lslv lvDMPbackup
LOGICAL VOLUME:     lvDMPbackup            VOLUME GROUP:   sdbdmpvg
LV IDENTIFIER:      00f60f5200004c000000012abb2ed482.9 PERMISSION:     read/write
VG STATE:           active/complete        LV STATE:       opened/syncd
TYPE:               jfs2                   WRITE VERIFY:   off
MAX LPs:            6000                   PP SIZE:        256 megabyte(s)
COPIES:             1                      SCHED POLICY:   parallel
LPs:                4594                   PPs:            4594
STALE PPs:          0                      BB POLICY:      relocatable
INTER-POLICY:       minimum                RELOCATABLE:    yes
INTRA-POLICY:       middle                 UPPER BOUND:    1024
MOUNT POINT:        /sapdb/DMP/backup      LABEL:          /sapdb/DMP/backup

PP size: 256

Now, pop out your trusty calculator and find new LP value.

sappr08(DMP)# echo "1483264/256" | bc
5794
sappr08(DMP)#

So you need to increase at least 5794 PP to make 300GB filesystem extension successful. In this case, I’ll just raise my max PP to 6000.

sappr08(DMP)# chlv -x 6000 lvDMPbackup

Verify new PP value again with “lslv” command.

sappr08(DMP)# lslv lvDMPbackup
LOGICAL VOLUME:     lvDMPbackup            VOLUME GROUP:   sdbdmpvg
LV IDENTIFIER:      00f60f5200004c000000012abb2ed482.9 PERMISSION:     read/write
VG STATE:           active/complete        LV STATE:       opened/syncd
TYPE:               jfs2                   WRITE VERIFY:   off
MAX LPs:            6000                   PP SIZE:        256 megabyte(s)
COPIES:             1                      SCHED POLICY:   parallel
LPs:                4594                   PPs:            4594
STALE PPs:          0                      BB POLICY:      relocatable
INTER-POLICY:       minimum                RELOCATABLE:    yes
INTRA-POLICY:       middle                 UPPER BOUND:    1024
MOUNT POINT:        /sapdb/DMP/backup      LABEL:          /sapdb/DMP/backup
MIRROR WRITE CONSISTENCY: on/ACTIVE
EACH LP COPY ON A SEPARATE PV ?: no
Serialize IO ?:     NO
INFINITE RETRY:     no
DEVICESUBTYPE:      DS_LVZ
COPY 1 MIRROR POOL: None
COPY 2 MIRROR POOL: None
COPY 3 MIRROR POOL: None

Now you may proceed with filesystem extension.

sappr08(DMP)# chfs -a size=+300G /sapdb/DMP/backup
Filesystem size changed to 3037724672
sappr08(DMP)# df -g /sapdb/DMP/backup
Filesystem    GB blocks      Free %Used    Iused %Iused Mounted on
/dev/lvDMPbackup   1448.50    499.03   66%     4690     1% /sapdb/DMP/backup



               df -m [MB] / PPSize [MB] = Max LPs