Mirroring of Sybase devices

[Former Member]

Hello guys.

We use disk mirror to change the physical device or from file system to raw device (and vice-versa).

Another DBA said we could not mirror a device that was already mirrored in the past.

For example: I mirrored Dev1 to Dev2 and now I need to mirror Dev2 to Dev3. He said it would not work.

It doesn't make sense to me, but I would like to have confirmation it would be possible.

Thanks in advance.

Sergi T.

[former_member229302]

Hi Sergi,

The key is to unmirror from primary.  See below steps:

1> disk mirror name='pubs2data',mirror='c:\sybase\pubs2data1.dat'

2> go

Creating the physical file for the mirror...

Starting Dynamic Mirroring of 25600 pages for logical device 'pubs2data'.

         512 pages mirrored...

        1024 pages mirrored...

        1536 pages mirrored...

        2048 pages mirrored...

        2560 pages mirrored...

        3072 pages mirrored...

        3584 pages mirrored...

        4096 pages mirrored...

        4608 pages mirrored...

        5120 pages mirrored...

        5632 pages mirrored...

        6144 pages mirrored...

        6656 pages mirrored...

        7168 pages mirrored...

        7680 pages mirrored...

        8192 pages mirrored...

        8704 pages mirrored...

        9216 pages mirrored...

        9728 pages mirrored...

       10240 pages mirrored...

       10752 pages mirrored...

       11264 pages mirrored...

       11776 pages mirrored...

       12288 pages mirrored...

       12800 pages mirrored...

       13312 pages mirrored...

       13824 pages mirrored...

       14336 pages mirrored...

       14848 pages mirrored...

       15360 pages mirrored...

       15872 pages mirrored...

       16384 pages mirrored...

       16896 pages mirrored...

       17408 pages mirrored...

       17920 pages mirrored...

       18432 pages mirrored...

       18944 pages mirrored...

       19456 pages mirrored...

       19968 pages mirrored...

       20480 pages mirrored...

       20992 pages mirrored...

       21504 pages mirrored...

       22016 pages mirrored...

       22528 pages mirrored...

       23040 pages mirrored...

       23552 pages mirrored...

       24064 pages mirrored...

       24576 pages mirrored...

       25088 pages mirrored...

       25600 pages mirrored...

1> disk unmirror name=pubs2data,side='primary',mode='remove'

2> go

1> disk mirror name='pubs2data',mirror='c:\sybase\pubs2data2.dat'

2> go

Creating the physical file for the mirror...

Starting Dynamic Mirroring of 25600 pages for logical device 'pubs2data'.

         512 pages mirrored...

        1024 pages mirrored...

        1536 pages mirrored...

        2048 pages mirrored...

        2560 pages mirrored...

        3072 pages mirrored...

        3584 pages mirrored...

        4096 pages mirrored...

        4608 pages mirrored...

        5120 pages mirrored...

        5632 pages mirrored...

        6144 pages mirrored...

        6656 pages mirrored...

        7168 pages mirrored...

        7680 pages mirrored...

        8192 pages mirrored...

        8704 pages mirrored...

        9216 pages mirrored...

        9728 pages mirrored...

       10240 pages mirrored...

       10752 pages mirrored...

       11264 pages mirrored...

       11776 pages mirrored...

       12288 pages mirrored...

       12800 pages mirrored...

       13312 pages mirrored...

       13824 pages mirrored...

       14336 pages mirrored...

       14848 pages mirrored...

       15360 pages mirrored...

       15872 pages mirrored...

       16384 pages mirrored...

       16896 pages mirrored...

       17408 pages mirrored...

       17920 pages mirrored...

       18432 pages mirrored...

       18944 pages mirrored...

       19456 pages mirrored...

       19968 pages mirrored...

       20480 pages mirrored...

       20992 pages mirrored...

       21504 pages mirrored...

       22016 pages mirrored...

       22528 pages mirrored...

       23040 pages mirrored...

       23552 pages mirrored...

       24064 pages mirrored...

       24576 pages mirrored...

       25088 pages mirrored...

       25600 pages mirrored...

1>

Hope this helps,

Jack

[Former Member]

Bret , One of our DBA initialized the file system device in wrong path  and expanded the user database size on that(2 devices ).

We would like to move the device to location where all devices present. Please lemme know how to do that . Can unmount and mount help ?

Example :

Step 1 :

unmount database DB_Name to '/sybase/DB_Name.manifest'

go

Step 2 :

Mount database all from '/sybase/DB_name.manifest'

using

'Correctlocation'='Logical_Name'

'Correctlocation'='Logical_name'

Remaining devices as present previously "Then

go

Will above fix will work ?

[former_member188958]

To the best of my knowledge, there should be no problem mirroring a previously mirrored device.

This should be an easy thing for you to test, just create a small device, mirror it, break the mirroring retaining the mirror side, mirror that device...

[Former Member]

Bret , One of our DBA initialized the file system device in wrong path  and expanded the user database size on that(2 devices ).

We would like to move the device to location where all devices present. Please lemme know how to do that . Can unmount and mount help ?

Example :

Step 1 :

unmount database DB_Name to '/sybase/DB_Name.manifest'

go

Step 2 :

Mount database all from '/sybase/DB_name.manifest'

using

'Correctlocation'='Logical_Name'

'Correctlocation'='Logical_name'

Remaining devices ad present already "The"

go

Will above fix will work ?