topic Re: Total disk size in Operating System - HP-UX

Total disk size

Nagaraj_4 — Tue, 04 Feb 2003 13:26:14 GMT

VG Name: VG00
PV Name,PE Size(MB),Allocated PE,FreePE,TotalPE

/dev/dsk/c1t2d0 4 2419 1921 4340
/dev/dsk/c2t2d0 4 2419 1921 4340
Total 4838 3842 8680

respectively.
Total available disk space is 34720MB (2*18GB disks) for VG00.

Is the above is correct or not.If not please give me right answer.

Re: Total disk size

Pete Randall — Tue, 04 Feb 2003 13:28:19 GMT

Yes, that's correct. On a 18GB disk, you'll get 4340 4MB physical extents.

Pete

Re: Total disk size

Marco Santerre — Tue, 04 Feb 2003 13:30:38 GMT

Hi,

It is fairly easy to calculate as all your disks are calculated in PE.

So whatever PE you are calculating will be
PE Size * 1024 * PE (all, Free, or Total) = Size in MB

so in this case

you have 4 * 1024 * 1921 = 7868 MB Free for one disk
so 7868 * 2 disks = 15736 MB Free

If it's total, you're looking at 35553 MB Total.

Re: Total disk size

Pete Randall — Tue, 04 Feb 2003 13:32:22 GMT

Calling it an 18GB disk is just an approximation:

# diskinfo /dev/rdsk/c1t6d0
SCSI describe of /dev/rdsk/c1t6d0:
vendor: SEAGATE
product id: ST318203LC
type: direct access
size: 17783240 Kbytes
bytes per sector: 512

If you do the math, 4340 4MB extents works out to 17776640 bytes. The rest is overhead.

Pete

Re: Total disk size

Ravi_8 — Tue, 04 Feb 2003 14:42:20 GMT

Hi,

from your post,
Tota PE in each disk is 4340
i.e
4*1024*4340 = 17776640 MB (size of each disk)

used (allocated)size in each disk
4*1024*2419 = 9908224 MB

remaining size in each disk
1776640-9908224=7868416 MB

total remaining size in vg00
2*7868416= 15736832MB

i.e 15.73GB

Re: Total disk size

David_246 — Tue, 04 Feb 2003 15:15:23 GMT

Hi,

diskinfo /dev/dsk/c1t2d0
diskinfo /dev/dsk/c2t2d0

should tell you a lot as well. Make sure that if the VG is mirrored you can actualy use only the half of it :)

Another easy way is :

vgdisplay vg00 :

<-- knip -->
Cur PV 2 (Mirrored !!)
Act PV 2
Max PE per PV 4350
VGDA 4
PE Size (Mbytes) 4
Total PE 4338 (* 4 (PE Size) /2 mirrors= total amount)
Alloc PE 4246
Free PE 92 (* 4(PE Size) /2 = total free in Mb)
<-- knip -->

Regs David