Sample cases of operations on cloned disks

The following sections contain examples of operations that can be used with cloned disks:

Enabling configuration database copies on tagged disks

In this example, the following commands have been used to tag some of the disks in an Hitachi TagmaStore array:

# vxdisk settag TagmaStore-USP0_28 t1=v1
# vxdisk settag TagmaStore-USP0_28 t2=v2
# vxdisk settag TagmaStore-USP0_24 t2=v2
# vxdisk settag TagmaStore-USP0_25 t1=v1

These tags can be viewed by using the vxdisk listtag command:

# vxdisk listtag

DEVICE               NAME    VALUE
TagmaStore-USP0_24   t2      v2
TagmaStore-USP0_25   t1      v1
TagmaStore-USP0_28   t1      v1
TagmaStore-USP0_28   t2      v2

The following command ensures that configuration database copies and kernel log copies are maintained for all disks in the disk group mydg that are tagged as t1:

# vxdg -g mydg set tagmeta=on tag=t1 nconfig=all nlog=all

The disks for which such metadata is maintained can be seen by using this command:

# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP   STATUS
TagmaStore-USP0_10 auto:cdsdisk -       -       online
TagmaStore-USP0_24 auto:cdsdisk mydg02  mydg    online
TagmaStore-USP0_25 auto:cdsdisk mydg03  mydg    online tagmeta
TagmaStore-USP0_26 auto:cdsdisk -       -       online
TagmaStore-USP0_27 auto:cdsdisk -       -       online
TagmaStore-USP0_28 auto:cdsdisk mydg01  mydg    online tagmeta

Alternatively, the following command can be used to ensure that a copy of the metadata is kept with a disk:

# vxdisk set TagmaStore-USP0_25 keepmeta=always 
# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP   STATUS
TagmaStore-USP0_10 auto:cdsdisk -       -       online
TagmaStore-USP0_22 auto:cdsdisk -       -       online
TagmaStore-USP0_23 auto:cdsdisk -       -       online
TagmaStore-USP0_24 auto:cdsdisk mydg02  mydg    online
TagmaStore-USP0_25 auto:cdsdisk mydg03  mydg    online keepmeta
TagmaStore-USP0_28 auto:cdsdisk mydg01  mydg    online
Importing cloned disks without tags

In the first example, cloned disks (ShadowImage™ devices) from an Hitachi TagmaStore array will be imported. The primary (non-cloned) disks, mydg01, mydg02 and mydg03, are already imported, and the cloned disks are not tagged.

# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP   STATUS
TagmaStore-USP0_3  auto:cdsdisk -       (mydg)  online udid_mismatch
TagmaStore-USP0_23 auto:cdsdisk mydg02   mydg   online
TagmaStore-USP0_25 auto:cdsdisk mydg03   mydg   online
TagmaStore-USP0_30 auto:cdsdisk -       (mydg)  online udid_mismatch
TagmaStore-USP0_31 auto:cdsdisk -       (mydg)  online udid_mismatch
TagmaStore-USP0_32 auto:cdsdisk mydg01   mydg   online

To import the cloned disks, they must be assigned a new disk group name, and their UDIDs must be updated:

# vxdg -n snapdg -o useclonedev=on -o updateid import mydg
# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP   STATUS
TagmaStore-USP0_3  auto:cdsdisk mydg03  snapdg   online clone_disk
TagmaStore-USP0_23 auto:cdsdisk mydg02  mydg    online
TagmaStore-USP0_25 auto:cdsdisk mydg03  mydg    online
TagmaStore-USP0_30 auto:cdsdisk mydg02  snapdg   online clone_disk
TagmaStore-USP0_31 auto:cdsdisk mydg01  snapdg   online clone_disk
TagmaStore-USP0_32 auto:cdsdisk mydg01  mydg    online

Note that the state of the imported cloned disks has changed from online udid_mismatch to online clone_disk.

In the next example, none of the disks (neither cloned nor non-cloned) have been imported:

# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP   STATUS
TagmaStore-USP0_3  auto:cdsdisk -       (mydg)  online udid_mismatch
TagmaStore-USP0_23 auto:cdsdisk -       (mydg)  online
TagmaStore-USP0_25 auto:cdsdisk -       (mydg)  online
TagmaStore-USP0_30 auto:cdsdisk -       (mydg)  online udid_mismatch
TagmaStore-USP0_31 auto:cdsdisk -       (mydg)  online udid_mismatch
TagmaStore-USP0_32 auto:cdsdisk -       (mydg)  online

To import only the cloned disks into the mydg disk group:

# vxdg -o useclonedev=on -o updateid import mydg
# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP   STATUS
TagmaStore-USP0_3  auto:cdsdisk mydg03  mydg    online clone_disk
TagmaStore-USP0_23 auto:cdsdisk -      (mydg)   online
TagmaStore-USP0_25 auto:cdsdisk -      (mydg)   online
TagmaStore-USP0_30 auto:cdsdisk mydg02  mydg    online clone_disk
TagmaStore-USP0_31 auto:cdsdisk mydg01  mydg    online clone_disk
TagmaStore-USP0_32 auto:cdsdisk -      (mydg)   online

In the next example, a cloned disk (BCV device) from an EMC Symmetrix DMX array is to be imported. Before the cloned disk, EMC0_27, has been split off from the disk group, the vxdisk list command shows that it is in the error udid_mismatch state:

# vxdisk -o alldgs list
DEVICE             TYPE         DISK    GROUP  STATUS
EMC0_1             auto:cdsdisk EMC0_1  mydg   online
EMC0_27            auto         -       -      error udid_mismatch

The symmir command is used to split off the BCV device:

# /usr/symcli/bin/symmir -g mydg split DEV001

After updating VxVM's information about the disk by running the vxdisk scandisks command, the cloned disk is in the online udid_mismatch state:

# vxdisk -o alldgs list
DEVICE             TYPE         DISK    GROUP  STATUS
EMC0_1             auto:cdsdisk EMC0_1  mydg   online
EMC0_27            auto:cdsdisk -       -      online udid_mismatch

The following command imports the cloned disk into the new disk group newdg, and updates the disk's UDID:

# vxdg -n newdg -o useclonedev=on -o updateid import mydg

The state of the cloned disk is now shown as online clone_disk:

# vxdisk -o alldgs list
DEVICE             TYPE         DISK    GROUP  STATUS
EMC0_1             auto:cdsdisk EMC0_1  mydg   online
EMC0_27            auto:cdsdisk EMC0_1  newdg  online clone_disk
Importing cloned disks with tags

In this example, cloned disks (BCV devices) from an EMC Symmetrix DMX array will be imported. The primary (non-cloned) disks, mydg01, mydg02 and mydg03, are already imported, and the cloned disks with the tag t1 are to be imported.

# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP  STATUS
EMC0_4             auto:cdsdisk mydg01  mydg   online
EMC0_6             auto:cdsdisk mydg02  mydg   online
EMC0_8             auto:cdsdisk -      (mydg)  online udid_mismatch
EMC0_15            auto:cdsdisk -      (mydg)  online udid_mismatch
EMC0_18            auto:cdsdisk mydg03  mydg   online
EMC0_24            auto:cdsdisk -      (mydg)  online udid_mismatch

The disks are tagged as follows:

# vxdisk listtag

DEVICE             NAME    VALUE
EMC0_4             t2      v2
EMC0_4             t1      v1
EMC0_6             t2      v2
EMC0_8             t1      v1
EMC0_15            t2      v2
EMC0_18            t1      v1
EMC0_24            t1      v1
EMC0_24            t2      v2

To import the cloned disks that are tagged as t1, they must be assigned a new disk group name, and their UDIDs must be updated:

# vxdg -n bcvdg -o useclonedev=on -o tag=t1 -o updateid import mydg
# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP  STATUS
EMC0_4             auto:cdsdisk mydg01  mydg   online
EMC0_6             auto:cdsdisk mydg02  mydg   online
EMC0_8             auto:cdsdisk mydg03  bcvdg  online clone_disk
EMC0_15            auto:cdsdisk -      (mydg)  online udid_mismatch
EMC0_18            auto:cdsdisk mydg03  mydg   online
EMC0_24            auto:cdsdisk mydg01  bcvdg  online clone_disk

As the cloned disk EMC0_15 is not tagged as t1, it is not imported. Note that the state of the imported cloned disks has changed from online udid_mismatch to online clone_disk.

By default, the state of imported cloned disks is shown as online clone_disk. This can be removed by using the vxdisk set command as shown here:

# vxdisk set EMC0_8 clone=off
# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP  STATUS
EMC0_4             auto:cdsdisk mydg01  mydg   online
EMC0_6             auto:cdsdisk mydg02  mydg   online
EMC0_8             auto:cdsdisk mydg03  bcvdg  online
EMC0_15            auto:cdsdisk -      (mydg)  online udid_mismatch
EMC0_18            auto:cdsdisk mydg03  mydg   online
EMC0_24            auto:cdsdisk mydg01  bcvdg  online clone_disk

In the next example, none of the disks (neither cloned nor non-cloned) have been imported:

# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP  STATUS
EMC0_4             auto:cdsdisk -       (mydg) online
EMC0_6             auto:cdsdisk -       (mydg) online
EMC0_8             auto:cdsdisk -       (mydg) online udid_mismatch
EMC0_15            auto:cdsdisk -       (mydg) online udid_mismatch
EMC0_18            auto:cdsdisk -       (mydg) online
EMC0_24            auto:cdsdisk -       (mydg) online udid_mismatch

To import only the cloned disks that have been tagged as t1 into the mydg disk group:

# vxdg -o useclonedev=on -o tag=t1 -o updateid import mydg
# vxdisk -o alldgs list

DEVICE             TYPE         DISK    GROUP  STATUS
EMC0_4             auto:cdsdisk -       (mydg) online
EMC0_6             auto:cdsdisk -       (mydg) online
EMC0_8             auto:cdsdisk mydg03  mydg   online clone_disk
EMC0_15            auto:cdsdisk -       (mydg) online udid_mismatch
EMC0_18            auto:cdsdisk -       (mydg) online
EMC0_24            auto:cdsdisk mydg01   mydg  online clone_disk

As in the previous example, the cloned disk EMC0_15 is not tagged as t1, and so it is not imported.

More Information

Enabling configuration database copies on tagged disks

Importing cloned disks without tags

Importing cloned disks with tags