AIXTips
 

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

cfgmgr (-v)    - cfgmgr is used to scan for new hardware use -v for verbose
 
lsdev -Cc <type>  will allow you to view the devices configured on the server.
     lsdev -Cc tape   - list tape and jukebox devices configured
     lsdev -Cc adapter - same as above for listing adapters 
rmdev -dl <device> - rmdev as the name implies is used to delete a device that has already been configured (use the device name listed from the output of lsdev -Cc <device> as the device name to remove, not the path to the /dev directory.

odmget

it's in the redbook!