Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Issue about PP size
Operating Systems AIX Issue about PP size Post 302757065 by MichaelFelt on Thursday 17th of January 2013 04:21:04 AM
Old 01-17-2013
The differences in PP - Physical Partition - sizes is caused by a number of defaults or constants re: the meta data for managing the volumes (aka disks) in a volume group.

The default size for a PP is actually 4M - dating back to when disks were smaller than 4G - because the default number of PP per volume has remained the same - 1016.

When disks were 4G and smaller the VGDA (Volume Group Descriptor Area) was 32M Byte large (or 8 x 4M, so a volume was 32M for VGDA (i.e. 8PP) with upto 1016 (1024 - 8) PP for volume group data.

The VGDA is an important structure - there are three kinds or sizes: normal, big and scaled. Normal is the original and it has space for 32 volumes of 1016 PP each, the big for 128 volumes of 1016 PP each, and the scaled originally began as 1024 disks of 1016 PP each, but now it is meant to scale/grow the max number of PP as the volume grows. But still the original factor of PP per disk is 1016.

Early on (with 4.5 and 9.1 G disks) AIX made changes to affect the number of PP per disk, e.g., so the PP size could be held constant even though disk sizes changed - however, the total number of PP per volume group (a VGDA constant) was fixed. The effect is that changing the number of PP per disk (the -t option of mkvg) means fewer disks can be included in a volume group (normal, and big are fixed at 32 and 128 by defaults).

So, basically, to keep a constant PP size over multiple disk sizes you need to divide the disk size by that PP size to see how many PP that will need, divide that number by 1016, round that number up to the next whole number (i.e., 2033 will need a factor of 3, or 3048 PP (-t 2 if I recall correctly) per volume while 2031 or 2032 will work with a factor of -t 1

Code:
-t 0 - default 1016
-t 1 - 2032 
-t 2 - 3048 
-t 3 - 4064
-t 4 - 5080
etc

Note: adding a disk larger than the original will mean it will not be fully utilized, however, you may change the scaling to a higher number dynamically (say you have been using 75G as a default, and want to add 150G disk/LUN. With no change, only 75G of the disk would be used. Change the scaling: the max number of disks declines, but the 150G disk can be fully utilized.

IMPOORTANT: you cannot change the PP size once a volume group is created. To change the PP size you must backup/restore to a new volume group.

Hope this helps!
 

10 More Discussions You Might Find Interesting

1. Red Hat

Linux / tape Block size issue

Can anyone tell me how to read and change the tape block size attached to a ultrium 2 (Faststor-2 tapedrive). I am using Redhat Linux AS 3.0 Update 7. :cool: I had a problem doing a recover with our backup software which is AS 3.0 Update 7. The message I received was: Failed to read 65536... (1 Reply)
Discussion started by: rcarpent
1 Replies

2. Solaris

command to find out total size of a specific file size (spread over the server)

hi all, in my server there are some specific application files which are spread through out the server... these are spread in folders..sub-folders..chid folders... please help me, how can i find the total size of these specific files in the server... (3 Replies)
Discussion started by: abhinov
3 Replies

3. Solaris

File size issue in Sol 5.9

Hi Gurus, An Application is not able to create files above 2.14gb in size in my Sol5.9 server. I have checked the file limit of the user running the Application and am attaching the same: boiadm: ulimit -a time(seconds) unlimited file(blocks) unlimited data(kbytes) ... (4 Replies)
Discussion started by: Hari_Ganesh
4 Replies

4. IP Networking

Issue File Extension is file Size

I am currently experiencing the file size being added to the file extension when transfering information from Command Line Client to a UNIX server. Does anyone know why this is happening and how do I stop the file size being added to the file extension. Example: football.pqt.11108... (1 Reply)
Discussion started by: Skeeterrock
1 Replies

5. Shell Programming and Scripting

The scripts not able to make the file to size 0, every times it go back to its original size

#!/bin/sh ########################################################################################################## #This script is being used for AOK application for cleaning up the .out files and zip it under logs directory. # IBM # Created #For pdocap201/pdoca202 .out files for AOK #1.... (0 Replies)
Discussion started by: mridul10_crj
0 Replies

6. HP-UX

Performance issue with 'grep' command for huge file size

I have 2 files; one file (say, details.txt) contains the details of employees and another file (say, emp.txt) has some selected employee names. I am extracting employee details from details.txt by using emp.txt and the corresponding code is: while read line do emp_name=`echo $line` grep -e... (7 Replies)
Discussion started by: arb_1984
7 Replies

7. AIX

Issue with increasing size of SAN disks on AIX

HI, I have had an issue last night while trying to extend a filesystsem . chvg -g <vg> command cameback with an error 0516-1790 chvg: Failed bootinfo -s hdisk9. Ensure the physical volume is available and try again. 0516-732 chvg: Unable to change volume group u01vg. the VG has 1... (1 Reply)
Discussion started by: xmen01
1 Replies

8. UNIX for Advanced & Expert Users

Physical disk IO size smaller than fragment block filesystem size ?

Hello, in one default UFS filesystem we have 8K block size (bsize) and 1K fragmentsize (fsize). At this scenary I thought all "FileSytem IO" will be 8K (or greater) but never smaller than the fragment size (1K). If a UFS fragment/blocksize is allwasy several ADJACENTS sectors on disk (in a ... (4 Replies)
Discussion started by: rarino2
4 Replies

9. UNIX for Dummies Questions & Answers

Ls directory size reporting byte size instead of file count

I have been searching both on Unix.com and Google and have not been able to find the answer to my question. I think it is partly because I can't come up with the right search terms. Recently, my virtual server switched storage devices and I think the problem may be related to that change.... (2 Replies)
Discussion started by: jmgibby
2 Replies

10. AIX

Filesystem reduction size issue

Hi, Need help with following case. I am trying to shring filesystem size and reduce few luns from volume group. Situation looks like that : # lsvg -l data1vg data1vg: LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT data1 jfs2 3200 3200 ... (5 Replies)
Discussion started by: borek
5 Replies

LEARN ABOUT OPENSOLARIS

mkfs_udfs

mkfs_udfs(1M)						  System Administration Commands					     mkfs_udfs(1M)

NAME

       mkfs_udfs - construct a udfs file system

SYNOPSIS

       mkfs -F udfs [generic_options] [-o specific_options] raw_device_file
	    [size]

DESCRIPTION

       This  is  the universal disk format file system (udfs) -specific module of the mkfs command. mkfs constructs a udfs file system with a root
       directory.

OPTIONS

       See mkfs(1M) for the list of supported generic_options.

       The following options are supported:

       -o specific_options    Specify a udfs-specific option. Specify udfs file system specific options in a comma-separated list with	no  inter-
			      vening spaces. If invalid options are specified, a warning message is printed and the invalid options are ignored.

			      The following specific_options are available:

			      N 	      Print the file system parameters without actually creating the file system.

			      label=string    Specify the label to be written into the volume header structures. Specify string as the name of the
					      label. If string is not specified, a default string is generated in the form of *NoLabel*.

OPERANDS

       The following operands are supported:

       raw_device_file	   Specify the disk partition on which to write.

       size		  Specify the number of 512-byte blocks in the file system.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWudf			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       fsck(1M),mkfs(1M), attributes(5)

DIAGNOSTICS

	 not currently a valid file system

       The specified device does not contain a valid udfs file system.

	 Invalid size: larger than the partition size

       Number of blocks given as parameter to create the file system is larger than the size of the device specified.

	 is mounted can't mkfs

       Device is in use, cannot create file system when the device is in use.

	 preposterous size

       Negative size parameter provided is invalid.

	 sector size must be between 512, 8192 bytes

       Sector size given is not in the valid range.

	 Volume integrity sequence descriptors too long
	 File set descriptor too long.

       Not enough space to create volume integrity sequence or file set descriptor.

	 mkfs: argument out of range

       One of the arguments is out of range.

	 mkfs: bad numeric arg

       One of the arguments is potentially a bad numeric.

NOTES

       You can use lofiadm to create a file that appears to a mkfs command (for example, mkfs_pcfs or mkfs_ufs) as a raw device. You can then  use
       a  mkfs	command  to  create  a	file system on that device. See lofiadm(1M) for examples of creating a UFS and a PC (FAT) file system on a
       device created by lofiadm.

SunOS 5.11							    17 Nov 2000 						     mkfs_udfs(1M)
All times are GMT -4. The time now is 02:32 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy