ASMCMD File Access Control Commands

This topic provides a summary of the ASMCMD Oracle ASM File Access Control commands.

For information about Oracle ASM File Access Control, see Managing Oracle ASM File Access Control for Disk Groups.

When administering users with ASMCMD, the users must be existing operating system users and their user names must have corresponding operating system user IDs. However, only users in the same cluster as the Oracle ASM instance can be validated.

Note:

When modifying ownership of files, the previous owner of a file cannot be dropped while the file is still open even after the ownership of the file has changed.

Table 10-94 lists the ASMCMD Oracle ASM File Access Control commands with brief descriptions.

Table 10-94 Summary of ASMCMD file access control commands

Command	Description
chgrp	Changes the user group of a file or list of files.
chmod	Changes permissions of a file or list of files.
chown	Changes the owner of a file or list of files.
groups	Lists the user groups to which a user belongs.
grpmod	Adds or removes users from an existing user group.
lsgrp	Lists user groups.
lsusr	Lists users in a disk group.
mkgrp	Creates a new user group.
mkusr	Adds a user to disk group.
passwd	Changes the password of a user.
rmgrp	Deletes a user group.
rmusr	Deletes a user from a disk group.
rpusr	Replaces one a user with another in a disk group.

chgrp

Purpose

Changes the user group of a file or list of files.

Syntax and Description

chgrp usergroup file [file ...]

Table 10-95 lists the syntax options for the chgrp command.

Table 10-95 Options for the chgrp command

Option	Description
`usergroup`	Name of the user group.
`file`	Name of a file.

Only the file owner or the Oracle ASM administrator can use this command. If the user is the file owner, then the user must also be either the owner or a member of the group for this command to succeed.

This command accepts a file name or multiple file names separated by spaces.

If you change the user group settings of an open file, then the operation currently running on the file completes using the old user group settings. The new settings take effect when re-authentication is required.

Examples

The following are examples of the chgrp command that change the Oracle ASM user group of the specified files.

Example 10-97 Using the ASMCMD chgrp command

ASMCMD [+] > chgrp asm_data +data/orcl/controlfile/Current.260.684924747

ASMCMD [+fra/orcl/archivelog/flashback] > chgrp asm_fra log_7.264.684968167 log_8.265.684972027

chmod

Purpose

Changes permissions of a file or list of files.

Syntax and Description

chmod mode file [file ...]

mode can be one of the following forms:

{ ugo | ug | uo | go | u | g | o | a } {+|- } {r|w |rw}

a specifies permissions for all users, u specifies permissions for the owner of the file, g specifies the group permissions, and o specifies permissions for other users.
{ 0|4|6} {0|4|6} {0|4|6}

The first digit specifies owner permissions, the second digit specifies group permissions, and the third digit specifies other permissions.

Table 10-96 lists the syntax options for the chmod command.

Table 10-96 Options for the chmod command

Option	Description
`6`	Read write permissions
`4`	Read only permissions
`0`	No permissions
`u`	Owner permissions, used with `r` or `w`
`g`	Group permissions, used with `r` or `w`
`o`	Other user permissions, used with `r` or `w`
`a`	All user permissions, used with `r` or `w`
`+`	Add a permission, used with `r` or `w`
`-`	Removes a permission, used with `r` or `w`
`r`	Read permission
`w`	Write permission
`file`	Name of a file

This command accepts a file name or multiple file names separated by spaces.

You can only set file permissions to read-write, read-only, and no permissions. You cannot set file permissions to write-only.

If you change the permission settings of an open file, then the operation currently running on the file completes using the old permission settings. The new settings take effect when re-authentication is required.

To view the permissions on a file, use the ASMCMD ls command with the --permission option. See "ls".

Examples

The following are examples of the chmod command that change the permissions of the specified files.

Example 10-98 Using the ASMCMD chmod command

ASMCMD [+fra/orcl/archivelog/flashback] > chmod ug+rw log_7.264.684968167 log_8.265.684972027

ASMCMD [+fra/orcl/archivelog/flashback] > chmod 640 log_7.264.684968167 log_8.265.684972027

ASMCMD [+] > ls --permission +fra/orcl/archivelog/flashback
User      Group      Permission  Name
grid      asm_fra     rw-r-----  log_7.264.684968167
grid      asm_fra     rw-r-----  log_8.265.684972027

chown

Purpose

Changes the owner of a file or list of files.

Syntax and Description

chown user[:usergroup ] file [file ...]

Table 10-97 lists the syntax options for the chown command.

Table 10-97 Options for the chown command

Option	Description
`user`	The name of the user that becomes the new owner.
`usergroup`	Name of the user group to which the user belongs.
`file`	Name of a file.

user typically refers to the user that owns the database instance home. Oracle ASM File Access Control uses the operating system (OS) name to identify a database.

This command accepts a file name or multiple file names separated by spaces.

If you change the ownership settings of an open file, then the following applies:

The operation currently running on the file completes using the old ownership and user group settings. The new settings take effect when re-authentication is required.
The new owner of the file cannot be dropped from the disk group until all instances in a cluster are restarted in a rolling manner.

Only the Oracle ASM administrator can use this command.

Examples

The following are examples of the chown command that change the owner of the specified files to the oracle1 operating system user.

Example 10-99 Using the ASMCMD chown command

ASMCMD [+fra/orcl/archivelog/flashback] > chown oracle1 log_7.264.684968167 log_8.265.684972027

ASMCMD [+fra/orcl/archivelog/flashback] > chown oracle1:asm_fra log_9.264.687650269

groups

Purpose

Lists all the user groups to which the specified user belongs.

Syntax and Description

groups diskgroup user

Table 10-98 lists the syntax options for the groups command.

Table 10-98 Options for the groups command

Option	Description
`diskgroup`	Name of the disk group to which the user belongs.
`user`	Name of the user.

Examples

The following is an example of the groups command that displays the user groups of the data disk group to which the oracle1 user belongs.

Example 10-100 Using the ASMCMD groups command

ASMCMD [+] > groups data oracle1
asm_data

grpmod

Purpose

Adds or removes operating system (OS) users to and from an existing Oracle ASM user group.

Syntax and Description

grpmod { --add | --delete } diskgroup usergroup user [user...]

Table 10-99 lists the syntax options for the grpmod command.

Table 10-99 Options for the grpmod command

Option	Description
`--add`	Specifies to add users to the user group.
`--delete`	Specifies to delete users from the user group.
`diskgroup`	Name of the disk group to which the user group belongs.
`usergroup`	Name of the user group.
`user`	Name of the user to add or remove from the user group.

Only the owner of the user group can use this command. The command requires the SYSASM privilege to run.

This command accepts an operating system user name or multiple user names separated by spaces. The operating system users are typically owners of a database instance home.

Examples

The following are examples of the grpmod command. The first example adds the oracle1 and oracle2 users to the asm_fra user group of the fra disk group. The second example removes the oracle2 user from the asm_data user group of the data disk group.

Example 10-101 Using the ASMCMD grpmod command

ASMCMD [+] > grpmod –-add fra asm_fra oracle1 oracle2

ASMCMD [+] > grpmod –-delete data asm_data oracle2

lsgrp

Purpose

Lists all Oracle ASM user groups or only groups that match a specified pattern.

Syntax and Description

lsgrp [--suppressheader][-a] [ -G diskgroup ] [ pattern ]

Table 10-100 lists the syntax options for the lsgrp command.

Table 10-100 Options for the lsgrp command

Option	Description
`--suppressheader`	Suppresses column headings.
`-a`	Lists all columns.
`-G` `diskgroup`	Limits the results to the specified disk group name.
`pattern`	Displays the user groups that match the pattern expression.

Examples

The following are examples of the lsgrp command. The first example displays a subset of information about the user groups whose name matches the asm% pattern. The second example displays all information about all the user groups.

Example 10-102 Using the ASMCMD lsgrp command

ASMCMD [+] > lsgrp asm%
DG_Name  Grp_Name   Owner
FRA      asm_fra    grid
DATA     asm_data   grid

ASMCMD [+] > lsgrp -a
DG_Name  Grp_Name   Owner     Members
FRA      asm_fra    grid      oracle1
DATA     asm_data   grid      oracle1 oracle2

lsusr

Purpose

Lists Oracle ASM users in a disk group.

Syntax and Description

lsusr [--suppressheader][-a] [-G diskgroup ] [ pattern ]

Table 10-101 lists the syntax options for the lsusr command.

Table 10-101 Options for the lsusr command

Option	Description
`-a`	List all users and the disk groups to which the users belong.
`--suppressheader`	Suppresses column headings.
`-G` `diskgroup`	Limits the results to the specified disk group name.
`pattern`	Displays the users that match the pattern expression.

Examples

The following is an example of the lsusr command. The example lists users in the data disk group and also shows the operating system Id assigned to the user.

Example 10-103 Using the ASMCMD lsusr command

ASMCMD [+] > lsusr -G data
User_Num OS_ID OS_Name 
3        1001  grid
1        1021  oracle1
2        1022  oracle2

mkgrp

Purpose

Creates a new Oracle ASM user group.

Syntax and Description

mkgrp diskgroup usergroup [user] [user...]

Table 10-102 lists the syntax options for the mkgrp command.

Table 10-102 Options for the mkgrp command

Option	Description
`diskgroup`	Name of the disk group to which the user group is added.
`usergroup`	Name of the user group to add. 30 is the maximum number of characters.
`user`	Name of the database user to add to the user group.

You can optionally specify a list of users to be included as members of the new user group.

Examples

The following is an example of the mkgrp command. This example creates the asm_data user group in the data disk group and adds the oracle1 and oracle2 users to the user group.

Example 10-104 Using the ASMCMD mkgrp command

ASMCMD [+] > mkgrp data asm_data oracle1 oracle2

mkusr

Purpose

Adds an operating system (OS) user to a disk group.

Syntax and Description

mkusr diskgroup user

Table 10-103 lists the syntax options for the mkusr command.

Table 10-103 Options for the mkusr command

Option	Description
`diskgroup`	Specifies the name of the disk group to which the user is to be added.
`user`	Name of the user to add.

The user to be added must be a valid operating system user. Only a user authenticated as SYSASM can run this command.

Examples

The following are examples of the mkusr command. The first example adds the oracle1 user to the data disk group. The second example adds the oracle2 user to the fra disk group.

Example 10-105 Using the ASMCMD mkusr command

ASMCMD [+] > mkusr data oracle1

ASMCMD [+] > mkusr fra oracle2

passwd

Purpose

Changes the password of a user.

Syntax and Description

passwd user

Table 10-104 lists the syntax options for the passwd command.

Table 10-104 Options for the passwd command

Option	Description
`user`	Name of the user.

An error is raised if the user does not exist in the Oracle ASM password file. The user is first prompted for the current password, then the new password. The command requires the SYSASM privilege to run.

Examples

The following is an example of the passwd command that changes the password of the oracle2 user.

Example 10-106 Using the ASMCMD passwd command

ASMCMD [+] > passwd oracle2
Enter old password (optional): 
Enter new password: ******

rmgrp

Purpose

Removes a user group from a disk group.

Syntax and Description

rmgrp diskgroup usergroup

Table 10-105 lists the syntax options for the rmgrp command.

Table 10-105 Options for the rmgrp command

Option	Description
`diskgroup`	Name of the disk group to which the user group belongs.
`usergroup`	Name of the user group to delete.

Removing a group might leave some files without a valid user group. To ensure that those files have a valid group, explicitly update those files to a valid user group. See "chgrp".

The command must be run by the owner of the user group and also requires the SYSASM privilege to run.

Examples

The following is an example of the rmgrp command that removes the asm_data user group from the data disk group.

Example 10-107 Using the ASMCMD rmgrp command

ASMCMD [+] > rmgrp data asm_data

rmusr

Purpose

Deletes an operating system (OS) user from a disk group.

Syntax and Description

rmusr [-r] diskgroup user

Table 10-106 lists the syntax options for the rmusr command.

Table 10-106 Options for the rmusr command

Option	Description
`-r`	Removes all files in the disk group that the user owns at the same time that the user is removed.
`diskgroup`	Specifies the name of the disk group from which the user is to be deleted.
`user`	Name of the user to delete.

The command requires the SYSASM privilege to run.

Examples

The following is an example of the rmusr command that removes the oracle2 user from the data disk group.

Example 10-108 Using the ASMCMD rmusr command

ASMCMD [+] > rmusr data oracle2

rpusr

Purpose

Replaces one operating system (OS) user with another in a disk group.

Syntax and Description

rpusr diskgroup user1 user2

Table 10-107 lists the syntax options for the rpusr command.

Table 10-107 Options for the rpusr command

Option	Description
`diskgroup`	Specifies the name of the disk group.
`user1`	Name of the user to be replaced.
`user2`	Name of user that replaces the existing user in the disk group.

The rpusr command replaces one operating system user with another in an Oracle ASM disk group. The replacement user must not be a user currently in the disk group user list.

If the command succeeds, all files that were previously owned by current user are now owned by the replacement user. The current user is automatically removed from the user list of the disk group. Adding the current user back to the disk group is possible but this user will not own any files.

When changing the ownership of an open file, the new owner cannot be dropped with the owner's files until all instances within a cluster are restarted.

The command requires the SYSASM privilege to run.

Examples

The following is an example of the rpusr command that replaces the oracle1 user with the oracle2 user in the data disk group.

Example 10-109 Using the ASMCMD rpusr command

ASMCMD [+] > rpusr data oracle1 oracle2