This procedure explains how to manually reduce the size of file systems in the rootvg volume group by creating a backup of your current rootvg volume group, and then reinstalling the operating system. It allows you to define the sizes of the logical partitions that are to be created during the installation process.
This procedure also explains how user-defined volume groups may be imported into your newly installed operating system.
Note: It is recommended that you create a separate backup of all file systems that are not contained in the rootvg volume group before performing this procedure.
This example uses the /usr file system as an example for reducing a file system in the rootvg volume group. If you want to reduce all file systems to their minimum size, the simplest way is to set SHRINK to yes during BOS install. Setting SHRINK to yes overrides any changes you make in the /image.data file described below.
Attention: Only delete files that you have created or that you know are not needed on your system. If in doubt, do not delete the file.
mkszfileThis creates the file / image.data, which contains a list of the active file systems in the rootvg volume group that will be included in the installation procedure.
lv_data: VOLUME_GROUP= rootvg . . . LPs= 58 . . . MOUNT_POINT= /usr . . . LV_MIN_LPs= 51You can either increase or decrease the number of logical partitions needed to contain the file system data. The default size of each additional logical partition is 4MB (defined in the PP_SIZE entry of the image.data file).
Attention: If you enter a value that is less than the minimum size required to contain the current data (indicated in the LV_MIN_LPs entry), the reinstallation process will fail. Use the df -k command to see the current blocks used in the file systems; then divide this number by 1024 to get the total MB of the file system.
fs_data: FS_NAME= /usr . . . FS_SIZE= 475136 . . . FS_MIN_SIZE= 417792The FS_SIZE value is calculated:
FS_SIZE = PP_SIZE ( in KB ) * 2 ( 512-blocks) * LPsGiven the values for LV_DATA in step 6, FS_SIZE would come out to be:
475136 = 4096 * 2 * 58
varyoffvg VGName exportvg VGName
mksysb /dev/rmt0This will do a complete system backup, which will include file system size information (in the /image.data file) for use in the installation procedure.
importvg -y VGName PVName
mount all
Note: You may get "Device Busy" messages about file systems that are already mounted. These messages can be ignored.