Purpose

Checks and repairs an Oracle ACFS file system on the AIX operating system.

Syntax and Description

fsck -V acfs [-n|-y] [-o options] volume_device

Table 16-13 contains the options available with the AIX fsck command.

fsck checks and repairs an existing Oracle ACFS. This command can only be run on a dismounted file system. root privileges are required to run fsck. The Oracle ACFS driver must be loaded for fsck to work.

By default, fsck only checks for and reports any errors. The -a flag must be specified to instruct fsck to fix errors in the file system. Do not interrupt fsck during the repair operation.

In a few cases, fsck prompts for questions before proceeding to check a file system. These cases include:

• If fsck detects that another fsck is in progress on the file system

• If fsck detects that the Oracle ACFS driver is not loaded

• If the file system does not appear to be Oracle ACFS

In checking mode, fsck also prompts if there are transaction logs that have not been processed completely due to an incomplete shutdown. To run in a non-interactive mode, include either the -y or -n options to answer yes or no to any questions.

fsck creates working files before it checks a file system. These working files are created in /usr/tmp if space is available. /tmp is used if /usr/tmp does not exist. If insufficient space is available in the tmp directory, fsck attempts to write to the current working directory. The files that fsck creates are roughly the size of the file system being checked divided by 32K. At most three such files are allocated. For example, a 2 GB file system being checked causes fsck to generate one to three 64K working files in the /usr/tmp directory. These files are deleted after fsck has finished.

In the event that fsck finds a file or directory in the file system for which it cannot determine its name or intended location (possibly due to a corruption in its parent directory), it places this object in the /lost+found directory when fsck is run in fix mode. For security reasons only the root user on Linux can read files in /lost+found. If the administrator can later determine the original name and location of the file based on its contents, the file can be moved or copied into its intended location.

The file names in the /lost+found directory are in the following formats:

parent.id.file.id.time-in-sec-since-1970
parent.id.dir.id.time-in-sec-since-1970

The id fields are the internal Oracle ACFS numeric identifiers for each file and directory in the file system.

You can use acfsutil info id id mount_point to attempt to determine the directory associated with parent.id. This directory is assumed to be where the deleted object originated. For information about acfsutil info, see "acfsutil info file".

If the parent directory is not known, the parent id field is set to UNKNOWN.

Examples

The following example shows how to check and repair an Oracle ACFS file system.

Purpose

Creates an Oracle ACFS file system on the AIX operating system.

Syntax and Description

mkfs -V acfs -o h /dev/null
mkfs -V acfs [-v name ] [-s size][-o options] volume_device 
       [-c release_version]

mkfs -V acfs -o h /dev/null displays usage text and exits.

Table 16-14 contains the options available with the AIX mkfs command.

You can use mkfs to create the on disk structure needed for Oracle ACFS file system to be mounted. The mkfs command is the traditional Linux command used to build a file system. After mkfs runs successfully, the USAGE column in the V$ASM_VOLUME view displays ACFS. root privilege is not required. The ownership of the volume device file dictates who can run this command.

The value specified with the -c release_version option must be greater than or equal to the value of COMPATIBLE.ADVM for the disk group, and must be less than or equal to the running Oracle Grid infrastructure release version. If —c release_version is not specified, the value of COMPATIBLE.ADVM is used. After the compatibility is set, it cannot be downgraded. The —c release_version option can be used in situations where it is not possible, or desirable, to update COMPATIBLE.ADVM and COMPATIBLE.ASM for the disk group, but you want to use an Oracle ACFS feature that requires a compatibility increase. After the Oracle ACFS compatibility is updated, it is no longer possible to mount the file system with an older Oracle Grid infrastructure release. To change the compatibility of an existing file system, refer to acfsutil compat set. For information about Oracle ASM disk group compatibility attributes, see Disk Group Compatibility.

The minimum file system size is 200 MB for the 512 byte metadata block size format and 512 MB for the 4 KB metadata block size format.

The Oracle ACFS driver must be loaded for mkfs to work.

4 KB Sector/Metadata

The following list summarizes the use of the -o i option and metadata block size based on the value of the COMPATIBLE.ADVM disk group attribute.

• If COMPATIBLE.ADVM is set to 12.2 or greater, then the metadata block size is 4096 bytes by default.

• If COMPATIBLE.ADVM is set to less than 12.2, then the block size is set to 512 bytes.

• If COMPATIBLE.ADVM is set to less than 12.2 and the logical sector size is not 512 bytes, then the command fails.

User data IO continues to support transfers as small as 512 bytes for normal user IO requests. When the Oracle ADVM volume of the file system has a logical disk sector size of 4 K, user Direct IO requests should be aligned on 4 K file offsets and be a multiple of 4 KB lengths for the best performance. Note that only 4 K metadata block size formats support ADVM volumes with 4 K logical disk sectors.

The COMPATIBLE.ADVM value must be set to 12.2 or higher to format an Oracle ADVM volume whose logical disk size is 4096 or to use the -o i=4096 option to format an Oracle ADVM volume whose logical disk sector size is 512 bytes.

Examples

Before creating an Oracle ACFS file system, first determine which Oracle ADVM volume devices are available. You can use the ASMCMD volinfo command to display information about the volumes and volume devices.

ASMCMD [+] > volinfo -a
...
         Volume Name: VOLUME1
         Volume Device: /dev/asm/volume1-123
         State: ENABLED
... 

For more information about volinfo, refer to Managing Oracle ADVM with ASMCMD.

Next create an Oracle ACFS file system on the volume device file.

Purpose

Mounts an Oracle ACFS file system on the AIX operating system.

Syntax and Description

mount -V acfs -o h /dev/null /xxx
mount -v acfs [-o options] volume_device mount_point

mount -V acfs -o h /dev/null /xxx displays usage text and exits.

Table 16-15 contains the options available with the mount command.

mount attaches a file system to the Oracle ACFS hierarchy at the mount point that is the name of a directory. The mount happens on the node where the mount command was issued. The mount command returns an error if the file system is not in a dismounted state on this node.

It is not always possible to return the cause of a mount failure to the mount command. When this happens Oracle ACFS writes the cause of the failure to the system console and associated system log file.

After mount runs successfully, the MOUNTPATH field in the V$ASM_VOLUME view displays the directory name on which the file system is now mounted.

An Oracle ACFS file system should only be mounted on one mount point. The same mount point name should be used on all cluster members.

root privilege is required to run mount.

Examples

The first example shows how to mount volume1-123 on the mount point /acfsmounts/acfs1. The second example shows how to mount all the registered Oracle ACFS file systems. The dummy names (none) have been entered as placeholders for the device and directory as these arguments are required, but not used, when the all option is specified.

Purpose

Dismounts an Oracle ACFS file system on the AIX operating system.

Syntax and Description

umount [mount_point | volume_device]
umountall -F acfs

unmountall -F acfs dismounts all Oracle ACFS file systems.

Table 16-16 contains the options available with the umount command.

umount and umountall detach an Oracle ACFS from the file system hierarchy on the current node.

The umount and umountall commands do not return control back to the operating system prompt until the file system has been completely unmounted.

If a file system is busy, umount and umountall fail.

root privileges are required to run the umount and umountall commands.

Examples

The following examples show how to dismount an Oracle ACFS file system. The first example specifies the mount point of the file system to dismount. The second example specifies the volume device associated with the file system to dismount. The third example dismounts all Oracle ACFS file systems.