Veritas InfoScale™ 7.4 Solutions Guide - Solaris
- Section I. Introducing Veritas InfoScale
- Section II. Solutions for Veritas InfoScale products
- Section III. Improving database performance
- Overview of database accelerators
- Improving database performance with Veritas Quick I/O
- About Quick I/O
- Improving database performance with Veritas Cached Quick I/O
- Improving database performance with Veritas Concurrent I/O
- Section IV. Using point-in-time copies
- Understanding point-in-time copy methods
- Backing up and recovering
- Preserving multiple point-in-time copies
- Online database backups
- Backing up on an off-host cluster file system
- Database recovery using Storage Checkpoints
- Backing up and recovering in a NetBackup environment
- Off-host processing
- Creating and refreshing test environments
- Creating point-in-time copies of files
- Section V. Maximizing storage utilization
- Optimizing storage tiering with SmartTier
- Optimizing storage with Flexible Storage Sharing
- Optimizing storage tiering with SmartTier
- Section VI. Migrating data
- Understanding data migration
- Offline migration from Solaris Volume Manager to Veritas Volume Manager
- How Solaris Volume Manager objects are mapped to VxVM objects
- Overview of the conversion process
- Planning the conversion
- Preparing a Solaris Volume Manager configuration for conversion
- Setting up a Solaris Volume Manager configuration for conversion
- Converting from the Solaris Volume Manager software to VxVM
- Post conversion tasks
- Online migration of a native file system to the VxFS file system
- Migrating a source file system to the VxFS file system over NFS v3
- VxFS features not available during online migration
- Migrating storage arrays
- Migrating data between platforms
- Overview of the Cross-Platform Data Sharing (CDS) feature
- CDS disk format and disk groups
- Setting up your system to use Cross-platform Data Sharing (CDS)
- Maintaining your system
- Disk tasks
- Disk group tasks
- Displaying information
- File system considerations
- Specifying the migration target
- Using the fscdsadm command
- Maintaining the list of target operating systems
- Migrating a file system on an ongoing basis
- Converting the byte order of a file system
- Migrating from Oracle ASM to Veritas File System
- Section VII. Veritas InfoScale 4K sector device support solution
Tasks for setting up Quick I/O in a database environment
Quick I/O is included in the VxFS package shipped with Veritas InfoScale Storage Foundation Standard and Enterprise products. By default, Quick I/O is enabled when you mount a VxFS file system.
If Quick I/O is not available in the kernel, or a Veritas InfoScale Storage or Veritas InfoScale Enterprise product license is not installed, a file system mounts without Quick I/O by default, the Quick I/O file name is treated as a regular file, and no error message is displayed. If, however, you specify the -o qio option, the mount command prints the following error message and terminates without mounting the file system.
VxFDD: You don't have a license to run this program vxfs mount: Quick I/O not available
To use Quick I/O, you must:
Preallocate files on a VxFS file system
Preallocating database files for Quick I/O allocates contiguous space for the files. The file system space reservation algorithms attempt to allocate space for an entire file as a single contiguous extent. When this is not possible due to lack of contiguous space on the file system, the file is created as a series of direct extents. Accessing a file using direct extents is inherently faster than accessing the same data using indirect extents. Internal tests have shown performance degradation in OLTP throughput when using indirect extent access. In addition, this type of preallocation causes no fragmentation of the file system.
You must preallocate Quick I/O files because they cannot be extended through writes using their Quick I/O interfaces. They are initially limited to the maximum size you specify at the time of creation.
Use a special file naming convention to access the files
VxFS uses a special naming convention to recognize and access Quick I/O files as raw character devices. VxFS recognizes the file when you add the following extension to a file name:
::cdev:vxfs:
Whenever an application opens an existing VxFS file with the extension ::cdev:vxfs: (cdev being an acronym for character device), the file is treated as if it were a raw device. For example, if the file temp01 is a regular VxFS file, then an application can access temp01 as a raw character device by opening it with the name:
.temp01::cdev:vxfs:
Note:
We recommend reserving the ::cdev:vxfs: extension only for Quick I/O files. If you are not using Quick I/O, you could technically create a regular file with this extension; however, doing so can cause problems if you later enable Quick I/O.
Depending on whether you are creating a new database or are converting an existing database to use Quick I/O, you have the following options:
If you are creating a new database to use Quick I/O:
You can use the qiomkfile command to preallocate space for database files and make them accessible to the Quick I/O interface.
You can use the setext command to preallocate space for database files and create the Quick I/O files.
If you are converting an existing database:
You can create symbolic links for existing VxFS files, and use these symbolic links to access the files as Quick I/O files.