How to Restore a savevg with a Larger PPsize


Contents

About this document
Creating a savevg with a larger PPsize
Changing the PPsize on an existing savevg

About this document

This document describes how to restore a savevg image with a larger PPsize. Information in this document is valid for AIX Versions 4.1.x and 4.2.x.

WARNING: This procedure is valid ONLY with a savevg image and will not work with a Sysback 6000 system backup.


Creating a savevg with a larger PPsize

If the ability to rerun the savevg is available, the following procedure allows you to create a savevg with a larger PPsize.

  1. To create a new /tmp/vgdata/<vgname>/<vgname>.data file, run the following command.
  2.             mkvgdata <vgname>
    

    vgname is the name of the volume group to be backed up.

  3. Change directories to /tmp/vgdata/<vgname> and vi the <vgname>.data file.
  4. Enter:
                cd /tmp/vgdata/<vgname>
                vi <vgname>.data
    
  5. The following examples show a vg_data and a lv_data stanza of an <vgname>.data file. Examples 1 and 3 are before editing, and examples 2 and 4 are after editing. The first and third examples are with a 4MG PPsize, while the second and fourth examples show the edited version with a larger PPsize. The lines that need changes are marked with a -->.
  6. To view and edit the file, execute:

                    vi  <vgname>.data
    

    Example 1

                            vg_data:
            			VGNAME= <vgname>
            		 -->	PPSIZE= 4
            			VARYON= yes
            			VG_SOURCE_DISK_LIST= hdisk1
    				QUORUM= 2
            			CONC_CAPABLE= no
            			CONC_AUTO= no
    

    Example 2

                            vg_data:
                                    VGNAME= <vgname>
                             -->    PPSIZE= 8
                                    VARYON= yes
                                    VG_SOURCE_DISK_LIST= hdisk1
                                    QUORUM= 2
                                    CONC_CAPABLE= no
                                    CONC_AUTO= no
    

    Example 3

                            lv_data:
                                    VOLUME_GROUP= <vgname>
                                    LV_SOURCE_DISK_LIST=  hdisk1
                                    LV_IDENTIFIER= 00000001113f3c62.5
                                    LOGICAL_VOLUME= lv00
                                    VG_STAT= active/complete
                                    TYPE= jfs
                                    MAX_LPS= 512
                                    COPIES = 1
                              -->   LPs = 70
                                    STALE_PPs= 0
                                    INTER_POLICY= minimum
                                    INTRA_POLICY= center
                                    MOUNT_POINT= /apps
                                    MIRROR_WRITE_CONSISTENCY= on
                                    LV_SEPARATE_PV= yes
                                    PERMISSION= read/write
                                    LV_STATE= opened/syncd
                                    WRITE_VERIFY= off
                              -->   PP_SIZE= 4
                                    SCHED_POLICY= parallel
                              -->   PP = 70
                                    BB_POLICY= relocatable
                                    RELOCATABLE= yes
                                    UPPER_BOUND= 32
                                    LABEL= /apps
                                    MAPFILE=
                              -->   LV_MIN_LPS= 68
    

    Example 4

                            lv_data:
                                    VOLUME_GROUP= <vgname>
                                    LV_SOURCE_DISK_LIST=  hdisk1
                                    LV_IDENTIFIER= 00000001113f3c62.5
                                    LOGICAL_VOLUME= lv00
                                    VG_STAT= active/complete
                                    TYPE= jfs
                                    MAX_LPS= 512
                                    COPIES = 1
                              -->   LPs = 35
                                    STALE_PPs= 0
                                    INTER_POLICY= minimum
                                    INTRA_POLICY= center
                                    MOUNT_POINT= /apps
                                    MIRROR_WRITE_CONSISTENCY= on
                                    LV_SEPARATE_PV= yes
                                    PERMISSION= read/write
                                    LV_STATE= opened/syncd
                                    WRITE_VERIFY= off
                              -->   PP_SIZE= 8
                                    SCHED_POLICY= parallel
                              -->   PP = 35
                                    BB_POLICY= relocatable
                                    RELOCATABLE= yes
                                    UPPER_BOUND= 32
                                    LABEL= /apps
                                    MAPFILE=
                              -->   LV_MIN_LPS= 34
    

    NOTE: In example 2, the PPsize has been changed from 4 to 8. In example 4, the LPs (logical partitions) have been divided by two, the PP_SIZE has been changed to 8, the PP (physical partitions) has been divided by two, and the LV_MIN_LPS has also been divided by two. The division of the LPs, PP, and LV_MIN_LPS is necessary so that the logical volume is created at the same size. The following is a division table to use as a reference:

    Original PPsize    New PPsize     Divide the LPs, LV_MIN_LPS by
           4               8                        2
           4              16                        4
           4              32                        8
           8              16                        2
           8              32                        4
          16              32                        2
    

    If, when you are dividing, a half number is achieved, simply round up to the nearest whole number. So if the LPs and PP are at 51 and you divide this by 2 (51/2 = 25.5), round up the result to 26.

    Once all the changes have been made, save the file and exit.

  7. Run another savevg from the command line that will utilize your edited <vgname>.data file.
  8.                 savevg -f /dev/rmtX <vgname>  
    

    X is the number of your tape device.

    WARNING: Do not run the savevg in SMIT because this will update the <vgname>.data file and overwrite any changes made.

    WARNING: Do not run the savevg with the -i flag because this will update the <vgname>.data file as well.


Changing the PPsize on an existing savevg

If another savevg cannot be run, the following procedure can be used to restore a savevg with a larger PPsize.

All references to the tape device in the next section are as rmt0.

  1. On the target system, place the savevg tape in the tape drive.
  2. Remove the /tmp/vgdata directory:
  3.                 rm -r /tmp/vgdata 
    
  4. Restore the /tmp/vgdata directory from the savevg tape:
  5.                cd /
                   restore -xqvdf /dev/rmt0 ./tmp/vgdata                
    
  6. Follow the examples in step 3 of the preceding section to edit the /tmp/vgdata/<vgname>/<vgname>.data file and make the necessary changes. Once changes have been made, go directly to step 5 below.
  7. After making the changes to the <vgname>.data file, create a backbyname of /tmp/vgdata to run restvg against.
  8.                 cd /
    		find ./tmp/vgdata -print |backup -iqvf /tmp/vg.back
    

    This should back up the following files:

                    ./tmp/vgdata
    		./tmp/vgdata/vgdata.files
    		./tmp/vgdata/<vgname> 
    		./tmp/vgdata/<vgname>/filesystems
    		./tmp/vgdata/<vgname>/<vgname>.data 
    

    vgname is the name of your volume group.

  9. Verify that the files were backed up, and that the file can be read. Enter:
  10.                 restore -Tqvf /tmp/vg.back
    
  11. Run the restvg command to recreate the volume group on the hdisks you want. Enter:
  12. 		restvg -f /tmp/vg.back hdisk# hdisk# 
    
  13. This should complete fairly quickly, depending on how many logical volume and file systems are being created, and return to the command line.

    Verify that the volume group and file systems were recreated. Enter:

  14. 		lsvg -l <vgname>
    

    Verify the file systems mounted. Enter:

    		mount 
    
  15. If everything appears as it should, restore the files from the tape. Enter:
  16. 		cd /
    		restore -xqvdf /dev/rmt0  
    



[ Doc Ref: 91745667913562     Publish Date: May. 08, 2000     4FAX Ref: 2483 ]