Total Disk Space returning Negative number

[viswanath emani]

The attched script when executed on HP-UX box returns the total disk space as negative value. Also there are a total of 35 HD's on that machine. I suspect that integer value is overflown which is resulting the negative number.

Could anyone please let me know if you have come accross this problem and had any solution.

[R.K. #]

No Attachment..!

[Dennis Handly]

What shell are you using? If you use ksh, it has 64 bit integer arithmetic.
Otherwise, you should track the space in terms of megabytes, not bytes.
Or you can use awk's double arithmetic.

See this recent thread:
http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1395380

[R.K. #]

You can try this little script:


for I in `vxdisk list | grep -v DEVICE | awk '{print $1}'`
do
diskinfo /dev/rdsk/$I | grep size | awk '{print $2/1024/1024}' >> dsz
done
awk 'BEGIN {sum=0}{sum+=$1} END {print sum}' < dsz
rm dsz


NOTE: Size will come out in GB

[viswanath emani]

sorry i missed the attachment. Here is the following script :

x=`/bin/id|/usr/bin/cut -c5-11`;
if [ $x != "0(root)" ];then exit $?;
else disksum=0;
for device in `/usr/sbin/ioscan -fknCdisk | /bin/grep -e /dev/rdsk/ | /bin/cut -d "/" -f4`;
do type=`/usr/sbin/diskinfo -v /dev/rdsk/$device |/bin/grep type |/bin/awk '{print $2}'`;
if [ "$type" = "CD-ROM" ]; then i=0; else i=`/usr/sbin/diskinfo -v /dev/rdsk/$device |/bin/grep size | /bin/awk '{ print $2 }'`; fi;
disksum=`/bin/expr $disksum + $i`;
done ;
disksum=`/bin/echo "$disksum / 1024" | /bin/bc`;echo "${disksum}";fi

[Dennis Handly · Accepted solution]

>if [ $x != "0(root)" ]; then exit $?;
>else disksum=0;

I would suggest you not use else here. After exit, you don't need that case:
if [ $x != "0(root)" ]; then exit 1; fi
(( disksum=0 ))
...
if [ "$type" = "CD-ROM" ]; then (( i=0 ))
else
i=$(/usr/sbin/diskinfo -v /dev/rdsk/$device | awk '/size/ { print $2 }')
fi
(( disksum = disksum + i ))
done
(( disksum = disksum / 1024 ))

Or divide by 1024 in the loop so it won't overflow:
(( disksum = disksum + i / 1024 ))
done