InfoScale™ 9.0 Solutions Guide - AIX
- Section I. Introducing InfoScale
- Section II. Solutions for InfoScale products
- Section III. Stack-level migration to IPv6 or dual stack
- Section IV. Improving database performance
- Overview of database accelerators
- Improving database performance with Quick I/O
- About Quick I/O
- Tasks for setting up Quick I/O in a database environment
- Creating DB2 database containers as Quick I/O files using qiomkfile Creating Sybase files as Quick I/O files using qiomkfile
- Preallocating space for Quick I/O files using the setext command
- Accessing regular VxFS files as Quick I/O files
- Extending a Quick I/O file
- Disabling Quick I/O
- Improving database performance with Cached Quick I/O
- Improving database performance with Concurrent I/O
- Section V. Using point-in-time copies
- Understanding point-in-time copy methods
- Backing up and recovering
- Storage Foundation and High Availability solutions backup and recovery methods
- 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 VI. Maximizing storage utilization
- Optimizing storage tiering with SmartTier
- About SmartTier
- About VxFS multi-volume file systems
- About VxVM volume sets
- About volume tags
- SmartTier use cases for Sybase
- Setting up a filesystem for storage tiering with SmartTier
- Relocating old archive logs to tier two storage using SmartTier
- Relocating inactive tablespaces or segments to tier two storage
- Relocating active indexes to premium storage
- Relocating all indexes to premium storage
- Optimizing storage with Flexible Storage Sharing
- Optimizing storage tiering with SmartTier
- Section VII. Migrating data
- Understanding data migration
- Offline migration of native volumes and file systems to VxVM and VxFS
- About converting LVM, JFS and JFS2 configurations
- Initializing unused LVM physical volumes as VxVM disks
- Converting LVM volume groups to VxVM disk groups
- Volume group conversion limitations
- Conversion process summary
- Conversion of JFS and JFS2 file systems to VxFS
- Conversion steps explained
- Identify LVM disks and volume groups for conversion
- Analyze an LVM volume group to see if conversion is possible
- Take action to make conversion possible if analysis fails
- Back up your LVM configuration and user data
- Plan for new VxVM logical volume names
- Stop application access to volumes in the volume group to be converted
- Conversion and reboot
- Convert a volume group
- Take action if conversion fails
- Implement changes for new VxVM logical volume names
- Restart applications on the new VxVM volumes
- Tailor your VxVM configuration
- Restoring the LVM volume group configuration
- Examples of using vxconvert
- About test cases
- Converting LVM, JFS and JFS2 to VxVM and VxFS
- Online migration of native LVM volumes to VxVM volumes
- About online migration from Logical Volume Manager (LVM) volumes to VxVM volumes
- Online migration from LVM volumes in standalone environment to VxVM volumes
- Administrative interface for online migration from LVM in standalone environment to VxVM
- Preparing for online migration from LVM in standalone environment to VxVM
- Migrating from LVM in standalone environment to VxVM
- Reconfiguring the application to use VxVM volume device path
- Backing out online migration of LVM in standalone environment to VxVM
- Do's and Don'ts for online migration from LVM in standalone environment to VxVM
- Scenarios not supported for migration from LVM in standalone environment to VxVM
- Online migration from LVM volumes in VCS HA environment to VxVM volumes
- About online migration from LVM in VCS HA environment to VxVM
- Administrative interface for online migration from LVM in VCS HA environment to VxVM
- Preparing for online migration from LVM in VCS HA environment to VxVM
- Migrating from LVM in VCS HA environment to VxVM
- Migrating configurations with multiple volume groups
- Backing out online migration of LVM in VCS HA environment to VxVM
- Do's and Don'ts for online migration from LVM in VCS HA environment to VxVM
- Scenarios not supported for migration from LVM VCS HA environment to VxVM
- Online migration of a native file system to the VxFS file system
- About online migration of a native file system to the VxFS file system
- Administrative interface for online migration of a native file system to the VxFS file system
- Migrating a native file system to the VxFS file system
- Migrating a source file system to the VxFS file system over NFS v3
- Backing out an online migration of a native file system to the VxFS file system
- 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
- Changing the alignment of a disk group during disk encapsulation
- Changing the alignment of a non-CDS disk group
- Splitting a CDS disk group
- Moving objects between CDS disk groups and non-CDS disk groups
- Moving objects between CDS disk groups
- Joining disk groups
- Changing the default CDS setting for disk group creation
- Creating non-CDS disk groups
- Upgrading an older version non-CDS disk group
- Replacing a disk in a CDS disk group
- Setting the maximum number of devices for CDS disk groups
- Changing the DRL map and log size
- Creating a volume with a DRL log
- Setting the DRL map length
- Displaying information
- Determining the setting of the CDS attribute on a disk group
- Displaying the maximum number of devices in a CDS disk group
- Displaying map length and map alignment of traditional DRL logs
- Displaying the disk group alignment
- Displaying the log map length and alignment
- Displaying offset and length information in units of 512 bytes
- Default activation mode of shared disk groups
- Additional considerations when importing CDS disk groups
- File system considerations
- Considerations about data in the file system
- File system migration
- Specifying the migration target
- Using the fscdsadm command
- Checking that the metadata limits are not exceeded
- Maintaining the list of target operating systems
- Enforcing the established CDS limits on a file system
- Ignoring the established CDS limits on a file system
- Validating the operating system targets for a file system
- Displaying the CDS status of a file system
- Migrating a file system one time
- Migrating a file system on an ongoing basis
- When to convert a file system
- Converting the byte order of a file system
- Alignment value and block size
- Migrating a snapshot volume
- Section VIII. InfoScale 4K sector device support solution
How Quick I/O improves database performance
The benefits of using Quick I/O are:
Improved performance and processing throughput by having Quick I/O files act as raw devices.
Ability to manage Quick I/O files as regular files, which simplifies administrative tasks such as allocating, moving, copying, resizing, and backing up DB2 containers.
Ability to manage Quick I/O files as regular files, which simplifies administrative tasks such as allocating, moving, copying, resizing, and backing up Sybase dataservers.
Quick I/O's ability to access regular files as raw devices improves database performance by:
Table:
Quick I/O feature | Advantage |
|---|---|
Supporting direct I/O | I/O on files using read() and write() system calls typically results in data being copied twice: once between user and kernel space, and later between kernel space and disk. In contrast, I/O on raw devices is direct. That is, data is copied directly between user space and disk, saving one level of copying. As with I/O on raw devices, Quick I/O avoids extra copying. |
Avoiding kernel write locks on database files | When database I/O is performed using the write() system call, each system call acquires and releases a write lock inside the kernel. This lock prevents multiple simultaneous write operations on the same file. Because database systems usually implement their own locking to manage concurrent access to files, per file writer locks unnecessarily serialize I/O operations. Quick I/O bypasses file system per file locking and lets the database server control data access. |
Avoiding double buffering | Most database servers maintain their own buffer cache and do not need the file system buffer cache. Database data cached in the file system buffer is therefore redundant and results in wasted memory and extra system CPU utilization to manage the buffer. By supporting direct I/O, Quick I/O eliminates double buffering. Data is copied directly between the relational database management system (RDBMS) cache and disk, which lowers CPU utilization and frees up memory that can then be used by the database server buffer cache to further improve transaction processing throughput. |
Supporting AIX Fastpath asynchronous I/O | AIX Fastpath asynchronous I/O is a form of I/O that performs non-blocking system level reads and writes, allowing the system to handle multiple I/O requests simultaneously. Operating systems such as AIX provide support for asynchronous I/O on raw devices, but not on regular files. As a result, even if the database server is capable of using asynchronous I/O, it cannot issue asynchronous I/O requests when the database runs on file systems. Lack of asynchronous I/O significantly degrades performance. Quick I/O lets the database server take advantage of kernel-supported asynchronous I/O on file system files accessed using the Quick I/O interface. |