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Product: File System Guides | |
Manual: File System 4.1 Administrator's Guide |
Creating a Quick I/O File Using qiomkfile
The best way to make regular files accessible to the Quick I/O interface and preallocate space for them is to use the qiomkfile command. Unlike the VxFS setext command, which requires superuser privileges, any user who has read/write permissions can run qiomkfile to create the files. The qiomkfile command has five options:
You can specify file size in terms of bytes (the default), or in kilobytes, megabytes, gigabytes, sectors (512 bytes), or terabytes by adding a k, K, m, M, g, G, s, S, t, or T suffix. If the size of the file including the header is not a multiple of the file system block size, it is rounded to a multiple of the file system block size before preallocation. The qiomkfile command creates two files: a regular file with preallocated, contiguous space; and a symbolic link pointing to the Quick I/O name extension. For example, to create a 100 MB file named dbfile in /database, enter: $ qiomkfile -s 100m /database/dbfile In this example, the first file created is a regular file named /database/.dbfile (which has the real space allocated). The second file is a symbolic link named /database/dbfile. This is a relative link to /database/.dbfile via the Quick I/O interface, that is, to .dbfile::cdev:vxfs:. This allows .dbfile to be accessed by any database or application as a raw character device. To check the results, enter: $ ls -al -rw-r--r-- 1 oracle dba 104857600 Oct 22 15:03 .dbfile lrwxrwxrwx 1 oracle dba 19 Oct 22 15:03 dbfile -> \ .dbfile::cdev:vxfs: $ ls -lL crw-r----- 1 oracle dba 43,0 Oct 22 15:04 dbfile -rw-r--r-- 1 oracle dba 10485760 Oct 22 15:04 .dbfile If you specify the -a option to qiomkfile, an absolute path name (see Using Absolute or Relative Path Names) is used so /database/dbfile points to /database/.dbfile::cdev:vxfs:. To check the results, enter: $ ls -al -rw-r--r-- 1 oracle dba 104857600 Oct 22 15:05 .dbfile lrwxrwxrwx 1 oracle dba 31 Oct 22 15:05 dbfile -> /database/.dbfile::cdev:vxfs: |
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