Mirroring Root disk
To Mirror Root disks (or any other volume group)
extendvg rootgv hdiskX
mirrorvg rootvg
additional steps for rootvg
check the bootlist :
bootlist -o -m normal
add new disk to boot list (if missing)
bootlist -m normal hdisk0 hdisk1
update boot image:
bosboot -ad hdisk0
bosboot -ad hdisk1
Removing a Volume Group
to remove a volume group from the disk reducevg volumegroup (use -d to force)
Extending Dumpdev
AIX dump space waxes and wanes with system load
but can get critical
syslog will send this message : "The largest dump device is too small."
# errpt -a
-------------------------------------------------------------------------------
LABEL: DMPCHK_TOOSMALL
IDENTIFIER: E87EF1BE
Date/Time: Wed Mar 12 15:00:01 MEST
Sequence Number: 1112
Machine Id: 00CDD76D4C00
Node Id: boldtsmb0e1
Class: O
Type: PEND
Resource Name: dumpcheck
Description
The largest dump device is too small.
Probable Causes
Neither dump device is large enough to accommodate a system dump at this time.
Recommended Actions
Increase the size of one or both dump devices.
Detail Data
Largest dump device
#lg_dumplv
Largest dump device size in kb
1048576
Current estimated dump size in kb
1049600
-----------------------------------------------------------------------------------
Now you need to establish PP size and free space:
# lsvg rootvg
VOLUME GROUP: rootvg VG IDENTIFIER: 00cdd76d00004c00000001079dbde229
VG STATE: active PP SIZE: 128 megabyte(s)
VG PERMISSION: read/write TOTAL PPs: 2184 (279552 megabytes)
MAX LVs: 256 FREE PPs: 1995 (255360 megabytes)
LVs: 12 USED PPs: 189 (24192 megabytes)
OPEN LVs: 11 QUORUM: 1
TOTAL PVs: 4 VG DESCRIPTORS: 4
STALE PVs: 0 STALE PPs: 0
ACTIVE PVs: 4 AUTO ON: yes
MAX PPs per PV: 1016 MAX PVs: 32
LTG size: 128 kilobyte(s) AUTO SYNC: no
HOT SPARE: no BB POLICY: relocatable
FREE PPs shows you have 25GB free on the rootvg and your PP Size is 128mb (IE you can allocate fs extentions in 128mb chunks)
Now show your dump devices :
# sysdumpdev -l
primary /dev/lg_dumplv
secondary /dev/lg_dumplv2
copy directory /var/adm/ras
forced copy flag TRUE
always allow dump TRUE
dump compression OFF
# lslv lg_dumplv
LOGICAL VOLUME: lg_dumplv VOLUME GROUP: rootvg
LV IDENTIFIER: 00cdd76d00004c00000001079dbde229.10 PERMISSION: read/write
VG STATE: active/complete LV STATE: opened/syncd
TYPE: sysdump WRITE VERIFY: off
MAX LPs: 512 PP SIZE: 128 megabyte(s)
COPIES: 1 SCHED POLICY: parallel
LPs: 9 PPs: 8
STALE PPs: 0 BB POLICY: relocatable
INTER-POLICY: minimum RELOCATABLE: yes
INTRA-POLICY: middle UPPER BOUND: 32
MOUNT POINT: N/A LABEL: None
8PPs*128mb*1024 = 1048576 which matches the current size
Calculate the new dump size from the high water mark
1049600/1024/128 = 8.0078125 !!!! Hmmm ok so allocate one more PP just to keep it happy (bad example - I have had to add 12PPs on systems before)
Extent the dumpdev
# extendlv lg_dumplv 1
# lslv lg_dumplv
LOGICAL VOLUME: lg_dumplv VOLUME GROUP: rootvg
LV IDENTIFIER: 00cdd76d00004c00000001079dbde229.10 PERMISSION: read/write
VG STATE: active/complete LV STATE: opened/syncd
TYPE: sysdump WRITE VERIFY: off
MAX LPs: 512 PP SIZE: 128 megabyte(s)
COPIES: 1 SCHED POLICY: parallel
LPs: 9 PPs: 9
STALE PPs: 0 BB POLICY: relocatable
INTER-POLICY: minimum RELOCATABLE: yes
INTRA-POLICY: middle UPPER BOUND: 32
MOUNT POINT: N/A LABEL:
New size!
Now clear the error
# errclear 0
Clears all errors! - so if you have more than one problem don't do this until the end
Smit foo
Smity
Mixed Bag
odmget
it's in the redbook!