Determinig the size of a virtual SCSI harddisk 1

[madmurdock]

Hi all,

I am trying to find out the size of a Virtual SCSI harddisk, when it is not yet included in a VG and you do not have access to the VIO-Server. I need that for scripting, especially for automated creation of volumegroups with the proper PP-Size. The old-fashioned way to cast a: lsattr -El hdiskx gives no output regarding the size, so there is maybe another way?

Thanx for your ideas


mad

Advanced Interactive eXecutable

 

[p5wizard]

Does

lscfg -vl hdiskX

give any info?


HTH,

p5wizard

 

[madmurdock]

Sure, but not the information I needed ;-)

lscfg -vl hdiskx gives output similar to this:

hdisk2 U91113.550.65D7223-V8-C2-T1-L83000000000 Virtual-SCSI-disk

Well, a workaround for scripting would be to put these disk in a temporary VG, look fot the size and exportvg the VG. But that would be the last way....

mad

Advanced Interactive eXecutable

 

[p5wizard]

or use dd to estimate the size if you don't want to risk putting a disk that belongs to another (as yet unknown) VG in a temp VG and ruin the data:

#!/bin/ksh
# find out number of GB on any disk
# # #
disk=$1           # /dev/hdiskN format
blocksize=1000000 # dd-read a block of 1Mbyte
startcount=9999   # at address 9999000000 -> 10GB
# # #
# read the designated block
while dd if=$disk of=/dev/null \
      bs=${blocksize} skip=${startcount} count=1 2>/dev/null 
do
 # # #
 # increment to next GB 
 ((startcount=startcount+1000))
done
# # #
# size must be 1GB less than point we are now
((startcount=startcount-999))
((sizeGB=startcount/1000))
echo "${disk} is ${sizeGB} GB"

# timex disksize.ksh /dev/hdisk1
/dev/hdisk1 is 36 GB

real 1.24
user 0.07
sys 0.24


Takes a bit of time, but in any case less than creating a temp VG... ;-)



HTH,

p5wizard

 

[rzs0502]

How about `lspv hdisk0 | grep TOTAL PPs` ?

"If you always do what you've always done, you will always be where you've always been."

 

[rzs0502]

I didn't read correctly... Your disk in not part of you VG yet


"If you always do what you've always done, you will always be where you've always been."

 

[rzs0502]

If you have root you can issue
odmget -q "name=hdisk10 and attribute=size_in_mb" CuAt


"If you always do what you've always done, you will always be where you've always been."

 

[madmurdock]

hello rzs0502,

all these things do not work with virtual disks! So the output from the odmget-command are pretty similar to those you will get from the lsattr-command.

@p5wizard : THx for that, but 2 minutes are more than I need for creating and removing a VG... Anyway, exciting way...
mad

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[hirschaj]

have you tried using bootinfo -s hdiskx?


Jim Hirschauer

http://www.aixexpert.com

 

[p5wizard]

that's 1.24 seconds... (but bootinfo -s has the exact size in 0.00 seconds ;-)) My script only gives a rough estimate.

But bootinfo should also know about the size of VSCSI disks - I guess it just does an lseek(fd,0,SEEK_END) on the disk device and then divides the resulting address by 1048576



HTH,

p5wizard

 

[madmurdock]

@hirschaj: Absolutely, bootinfo -s does the trick. This info was really valuable for me!

Thx to all for the help, and:

@p5wizard: I got confused about the
real 1.24
user 0.07
sys 0.24

I thought of:

real 1m24,00s
user 0m7,00s
sys 0m24,00s

mad

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