what's that means in vms shadow?

[edward wang_1]

what's meaning of for "percent populated" and "local set"?
exmaple:
$ sh dev dsa /bit /full
Device BitMap Size Percent Type of Master Active Creation Cluster Local Delete Bitmap
Name ID (Bytes) Populated Bitmap Node Date/Time Size Set Pending Name
DSA20: 0001005C 2068 0.01% Minimerge HPS101 Yes 20-MAY-2010 16:27:13.31 127 0.01% No

[edward wang_1]

in show dev dsa/bit/full, we can see "percent populated" and "local set" option, I want to know what that means.
pls help, thanks

[P Muralidhar Kini]

Hi Edward,

>> sh dev dsa /bit /full
This command gives details about the BITMAP used for volume shadowing operation.
In your case the bitmap seems to be a Minimerge bitmap.

Refer the following link for more details -
http://www.openvms.compaq.com/openvms/journal/v11/hbmm_amcvp_openvms_shadowing.html
http://www.itec.suny.edu/scsys/vms/ovmsdoc0731/731final/5423/5423pro_011.html

Hope this helps.

Regards,
Murali

[edward wang_1]

Hi Kini

thank you help, but I need to know that means.

[P Muralidhar Kini]

Hi Edward,

Percent Populated
This indicates the exact percentage of the disk that has been copied or
merged. In your case, the bitmap is a minimerge and hence the percentage
should refer to the merge satus.

For more details, refer -
http://h71000.www7.hp.com/doc/732FINAL/DOCUMENTATION/PDF/aa-pvxmj-te.PDF
-> HP Volume Shadowing for OpenVMS

Regards,
Murali

[edward wang_1]

Hi Kini

thank so much.

how about "local set" means?

[P Muralidhar Kini · Accepted solution]

Hi Edward,

Looks like Percent Populated corresponds to Master bitmap and Local set
corresponds to the Local bitmap. I am not sure and need to dig through some docs
to confirm this.

For information on Master/Locak bitmap, refer
http://www.openvms.compaq.com/openvms/journal/v11/hbmm_amcvp_openvms_shadowing.html
-> Local & Master bitmaps

Regards,
Murali

[edward wang_1]

Hi Murali
thank you so much for help.

[P Muralidhar Kini]

Hi Edward,

Also,

Write bitmap -
A write bitmap is a data structure in memory that tracks the addresses of all
write operations and all data security erase (DSE) operations.

Master write bitmap -
A master write bitmap is created on the first OpenVMS Alpha system that
mounts the shadow set. It contains a record of all blocks that have been
changed on a shadow set

Local write bitmap -
A local write bitmap is a bitmap that is created when you mount or dismount a
minicopy-enabled shadow set. A local write bitmap communicates with the
master write bitmap to ensure that the master write bitmap has a record of
all changed blocks.

For more details, refer
http://h71000.www7.hp.com/doc/731final/5423/5423pro_014.html

Hope this helps.

Regards,
Murali

[edward wang_1]

Hi Murali

thank you detail description.

edward

[P Muralidhar Kini]

Hi Edward,

>> thank you detail description.
you are most welcome.

Also, in case you want some Volume Shadowing basics then refer -
http://h71000.www7.hp.com/doc/731final/5423/5423pro.html
-> Volume Shadowing for OpenVMS

Happy Volume Shadowing...

Regards,
Murali

[Robert Brooks_1]

Is there a problem you are trying to solve, or is your question out of idle curiousity?

-- Rob

[edward wang_1]

thanks all of you help