Raw I/o

UNIX AIX
1

Is there any system call available in AIX to read the size of raw disk?

If I use the command "lspv -L",it only gives size of PVs on which file system is there. I need to extract the size raw disk i.e. file system is not there on the disk.

Thanks,
Megha

2

bootinfo -s <hdiskXXX> gives you the size of the disk in MB.

3

I tried this also. But everytime with "bootinfo -s hdiskXX" it gave me 1024
Where on hdiskXXX no file system is there.

4

Have a look in smit, it can show the form of command it uses.

# this will list the physical disks
getlvodm -C

# this will show the status of the disk
lspv hdisk0

5

The problem is there is not a single solution to this, so i give you a list of options you have in order of preferability (is this a word? english is not my native language):

SCSI-disk and native SSA-disks (not SSA-RAID-volumes, etc.) have an attribute called "size_in_mb", which you could read. Example: to get the size of hdisk0 you can type (and get this sample information for a 18GB disk)

# lsattr -El hdisk0 -a size_in_mb
size_in_mb 18200 Size in Megabytes False

If the disk in question is in a volume group you can find out with lspv like this (output is exemplary):

# lspv hdisk4
PHYSICAL VOLUME:    hdisk4                   VOLUME GROUP:     joker_int_vg
PV IDENTIFIER:      000bf05d981228ff VG IDENTIFIER     000bf05d95422f4d
PV STATE:           active                                     
STALE PARTITIONS:   0                        ALLOCATABLE:      yes
PP SIZE:            64 megabyte(s)           LOGICAL VOLUMES:  4
TOTAL PPs:          1093 (69952 megabytes)   VG DESCRIPTORS:   2
FREE PPs:           130 (8320 megabytes)     HOT SPARE:        no
USED PPs:           963 (61632 megabytes)    MAX REQUEST:      256 kilobytes
FREE DISTRIBUTION:  00..00..00..00..130                        
USED DISTRIBUTION:  219..219..218..218..89

you could also use bootinfo, BUT: bootinfo is usually only executable by root, whereas lsattr is executable by everybody AND the bootinfo command won't work on some disks.

I hope this helps.

bakunin

6

Also usfull commands

lsvg |lsvg -il

lsvg |lsvg -ip

7

better use the "-o"-option of lsvg to get only the active VGs (the ones in the status VARYON), otherwise you will get a lot of error messages on the standby part of a HACMP cluster:

lsvg -o | lsvg -il

lsvg -o | lsvg -ip

bakunin