Hi all,

I have RS/6K running 4.2.1 with mirrored ROOTVG on 4.3 GB disks (hdisk0
& hdisk1). I want to take a system backup and JUST FOR verification
purpose wants to restore it on the SAME system (as I don't have any
spare system), but on DIFFERENT spare hard disks, of the size 18 GB
each. While restoring I may not be able to power down/disable hdisk0 &
hdisk1, i.e these two disks would be on line with 18GB disks.



I know that before running mksysb I need to edit /image.data file to
change PP size to 32 MB (currently it is 8 MB for 4.3 GB disks) under
vg_data stanza. Also I need to verify PROMPT=YES in /bosinst.data file.
Now my questions are :



1) Do I need to change PP size to 32 MB under all 'lv_data' stanza in
/image.data ?



2) According to new PP size do I need to change FS_SIZE under 'fs_data'
stanza in /image.data ?



4) After selecting target disks under Installation & Maintenance menu,
still is there any possibility that restore process may affect
existing rootvg on hdisk0 & hdisk1 ?



5) To avoid probable problem mentioned in Q-4, do I need to edit
/bosinst.data file to reflect location of the target disks (18 GB
disks) under 'target_disk_data' stanza ?



6) Suppose I succeed in restoring mksysb tape on new hard disks, now on
simply physically removing those disks, will I be able to boot from
hdisk0 again without any problem ?



6) Do you see any other potential problem in restoring this way ? Or
please let me know if I may be missing some steps for successful
restoration on bigger disks.



Your interest and responses will be highly appreciated..... TIA


--
KPS


Posted via http://dbforums.com

Originally posted by ketsak

> Hi all,

> I have RS/6K running 4.2.1 with mirrored ROOTVG on 4.3 GB disks
> (hdisk0 & hdisk1). I want to take a system backup and JUST FOR
> verification purpose wants to restore it on the SAME system (as I
> don't have any spare system), but on DIFFERENT spare hard disks, of
> the size 18 GB each. While restoring I may not be able to power
> down/disable hdisk0 & hdisk1, i.e these two disks would be on line
> with 18GB disks.

>

> I know that before running mksysb I need to edit /image.data file to
> change PP size to 32 MB (currently it is 8 MB for 4.3 GB disks) under
> vg_data stanza. Also I need to verify PROMPT=YES in /bosinst.data
> file. Now my questions are :

>

> 1) Do I need to change PP size to 32 MB under all 'lv_data' stanza in
> /image.data ?

>

> 2) According to new PP size do I need to change FS_SIZE under
> 'fs_data' stanza in /image.data ?

>

> 4) After selecting target disks under Installation & Maintenance menu,
> still is there any possibility that restore process may affect
> existing rootvg on hdisk0 & hdisk1 ?

>

> 5) To avoid probable problem mentioned in Q-4, do I need to edit
> /bosinst.data file to reflect location of the target disks (18 GB
> disks) under 'target_disk_data' stanza ?

>

> 6) Suppose I succeed in restoring mksysb tape on new hard disks, now
> on simply physically removing those disks, will I be able to boot
> from hdisk0 again without any problem ?

>

> 6) Do you see any other potential problem in restoring this way ? Or
> please let me know if I may be missing some steps for successful
> restoration on bigger disks.

>

> Your interest and responses will be highly appreciated..... TIA
>





No responses ????!!!!!! Need some expert advice..........


--
KPS


Posted via http://dbforums.com

ketsak <member44158@dbforums.com> writes:

>No responses ????!!!!!! Need some expert advice..........

Okay, I'll speak first. Don't do it. The odds of getting it right are
too small.

>> I have RS/6K running 4.2.1 with mirrored ROOTVG on 4.3 GB disks
>> (hdisk0 & hdisk1). I want to take a system backup and JUST FOR
>> verification purpose wants to restore it on the SAME system (as I
>> don't have any spare system), but on DIFFERENT spare hard disks, of
>> the size 18 GB each. While restoring I may not be able to power
>> down/disable hdisk0 & hdisk1, i.e these two disks would be on line
>> with 18GB disks.

>> I know that before running mksysb I need to edit /image.data file to
>> change PP size to 32 MB (currently it is 8 MB for 4.3 GB disks) under
>> vg_data stanza. Also I need to verify PROMPT=YES in /bosinst.data
>> file. Now my questions are :

>> 1) Do I need to change PP size to 32 MB under all 'lv_data' stanza in
>> /image.data ?

If you have just file systems, not raw LVs, I *think* you can leave
the PP stuff alone and just set SHRINK=yes. I'm pretty sure I've done
this at least once with no problems (but this might have been on AIX
later than 4.2.1).

If 4.2.1 doesn't support the SHRINK option, then you should adjust
all PP/LP sizes and counts. At least, I have done this and had the
restore work.

>> 2) According to new PP size do I need to change FS_SIZE under
>> 'fs_data' stanza in /image.data ?

The FS_SIZE is in blocks and doesn't need to change. You might end up
with unused space at the end of the LVs, but that is not important.

>> 4) After selecting target disks under Installation & Maintenance menu,
>> still is there any possibility that restore process may affect
>> existing rootvg on hdisk0 & hdisk1 ?

Yes! That's why I wouldn't try this without disconnecting hdisk0 and 1.
Especially with such an old AIX. If I remember correctly, if you had
two sets of disks that internally claimed to have the same LVs and you
somehow activated them both at the same time, the ODM got very confused.

>> 5) To avoid probable problem mentioned in Q-4, do I need to edit
>> /bosinst.data file to reflect location of the target disks (18 GB
>> disks) under 'target_disk_data' stanza ?

I would. Just in case.

>> 6) Suppose I succeed in restoring mksysb tape on new hard disks, now
>> on simply physically removing those disks, will I be able to boot
>> from hdisk0 again without any problem ?

Depends on how you've set your bootlist. If you set it to try the new
disks first, then hdisk0, you should be okay. After you are done with
the testing, change the bootlist to hdisk0 and 1 only again.

>> 6) Do you see any other potential problem in restoring this way ? Or
>> please let me know if I may be missing some steps for successful
>> restoration on bigger disks.

Create two mksysb images, one normal and one with your edited image.data and
bosinst.data files. That way, if the second one proves unreadable part way
through, and hdisk0 gets clobbered in spite of your care, you'll still
have the first tape to recover with.

--
Dale Talcott, IT Research Computing Services, Purdue University
aeh@quest.cc.purdue.edu http://quest.cc.purdue.edu/~aeh/

Just use Storix. It will let you select the disks to restore to, change
the LV and filesystem sizes, etc from the menus after you boot from the
tape. I know it will also look at your disk sizes and automatically
change the PP size of the VG and number of LPs in all the LVS if needed.
I have the full version, but I think I did all this even when I just had
the free version.

ketsak wrote:
> Hi all,
>
> I have RS/6K running 4.2.1 with mirrored ROOTVG on 4.3 GB disks (hdisk0
> & hdisk1). I want to take a system backup and JUST FOR verification
> purpose wants to restore it on the SAME system (as I don't have any
> spare system), but on DIFFERENT spare hard disks, of the size 18 GB
> each. While restoring I may not be able to power down/disable hdisk0 &
> hdisk1, i.e these two disks would be on line with 18GB disks.
>
>
>
> I know that before running mksysb I need to edit /image.data file to
> change PP size to 32 MB (currently it is 8 MB for 4.3 GB disks) under
> vg_data stanza. Also I need to verify PROMPT=YES in /bosinst.data file.
> Now my questions are :
>
>
>
> 1) Do I need to change PP size to 32 MB under all 'lv_data' stanza in
> /image.data ?
>
>
>
> 2) According to new PP size do I need to change FS_SIZE under 'fs_data'
> stanza in /image.data ?
>
>
>
> 4) After selecting target disks under Installation & Maintenance menu,
> still is there any possibility that restore process may affect
> existing rootvg on hdisk0 & hdisk1 ?
>
>
>
> 5) To avoid probable problem mentioned in Q-4, do I need to edit
> /bosinst.data file to reflect location of the target disks (18 GB
> disks) under 'target_disk_data' stanza ?
>
>
>
> 6) Suppose I succeed in restoring mksysb tape on new hard disks, now on
> simply physically removing those disks, will I be able to boot from
> hdisk0 again without any problem ?
>
>
>
> 6) Do you see any other potential problem in restoring this way ? Or
> please let me know if I may be missing some steps for successful
> restoration on bigger disks.
>
>
>
> Your interest and responses will be highly appreciated..... TIA
>
>
> --
> KPS
>
>
> Posted via http://dbforums.com