InfoScale™ 9.0 Storage Foundation Administrator's Guide - AIX
- Section I. Introducing Storage Foundation
- Overview of Storage Foundation
- How Dynamic Multi-Pathing works
- How Volume Manager works
- How Volume Manager works with the operating system
- How Volume Manager handles storage management
- Volume layouts in Veritas Volume Manager
- Online relayout
- Volume resynchronization
- Dirty region logging
- Volume snapshots
- FastResync
- How VxVM handles hardware clones or snapshots
- How Veritas File System works
- Section II. Provisioning storage
- Provisioning new storage
- Advanced allocation methods for configuring storage
- Customizing allocation behavior
- Using rules to make volume allocation more efficient
- Understanding persistent attributes
- Customizing disk classes for allocation
- Specifying allocation constraints for vxassist operations with the use clause and the require clause
- Creating volumes of a specific layout
- Customizing allocation behavior
- Creating and mounting VxFS file systems
- Creating a VxFS file system
- Mounting a VxFS file system
- tmplog mount option
- ioerror mount option
- largefiles and nolargefiles mount options
- Resizing a file system
- Monitoring free space
- Extent attributes
- Section III. Administering multi-pathing with DMP
- Administering Dynamic Multi-Pathing
- Discovering and configuring newly added disk devices
- About discovering disks and dynamically adding disk arrays
- How to administer the Device Discovery Layer
- Administering DMP using the vxdmpadm utility
- Gathering and displaying I/O statistics
- Specifying the I/O policy
- Discovering and configuring newly added disk devices
- Dynamic Reconfiguration of devices
- Reconfiguring a LUN online that is under DMP control using the Dynamic Reconfiguration tool
- Manually reconfiguring a LUN online that is under DMP control
- Managing devices
- Displaying disk information
- Changing the disk device naming scheme
- Adding and removing disks
- Event monitoring
- Administering Dynamic Multi-Pathing
- Section IV. Administering Storage Foundation
- Administering sites and remote mirrors
- About sites and remote mirrors
- Fire drill - testing the configuration
- Changing the site name
- Administering the Remote Mirror configuration
- Failure and recovery scenarios
- Administering sites and remote mirrors
- Section V. Optimizing I/O performance
- Section VI. Using Point-in-time copies
- Understanding point-in-time copy methods
- When to use point-in-time copies
- About Storage Foundation point-in-time copy technologies
- Volume-level snapshots
- Storage Checkpoints
- About FileSnaps
- About snapshot file systems
- Administering volume snapshots
- Traditional third-mirror break-off snapshots
- Full-sized instant snapshots
- Creating instant snapshots
- Adding an instant snap DCO and DCO volume
- Controlling instant snapshot synchronization
- Creating instant snapshots
- Cascaded snapshots
- Adding a version 0 DCO and DCO volume
- Administering Storage Checkpoints
- Storage Checkpoint administration
- Administering FileSnaps
- Administering snapshot file systems
- Understanding point-in-time copy methods
- Section VII. Optimizing storage with Storage Foundation
- Understanding storage optimization solutions in Storage Foundation
- Migrating data from thick storage to thin storage
- Maintaining Thin Storage with Thin Reclamation
- Reclamation of storage on thin reclamation arrays
- Identifying thin and thin reclamation LUNs
- InfoScale 4K sector device support solution
- Section VIII. Maximizing storage utilization
- Understanding storage tiering with SmartTier
- Creating and administering volume sets
- Multi-volume file systems
- Features implemented using multi-volume file system (MVFS) support
- Adding a volume to and removing a volume from a multi-volume file system
- Volume encapsulation
- Load balancing
- Administering SmartTier
- About SmartTier
- Placement classes
- Administering placement policies
- File placement policy rules
- Multiple criteria in file placement policy rule statements
- Using SmartTier with solid state disks
- Sub-file relocation
- Administering hot-relocation
- How hot-relocation works
- Moving relocated subdisks
- Compressing files
- About compressing files
- Use cases for compressing files
- Section IX. Administering and protecting storage
- Administering VxVM volumes as paging devices
- Managing volumes and disk groups
- Rules for determining the default disk group
- Moving volumes or disks
- Monitoring and controlling tasks
- Performing online relayout
- Adding a mirror to a volume
- Managing disk groups
- Disk group versions
- Displaying disk group information
- Importing a disk group
- Moving disk groups between systems
- Importing a disk group containing hardware cloned disks
- Handling conflicting configuration copies
- Destroying a disk group
- Backing up and restoring disk group configuration data
- Managing plexes and subdisks
- Decommissioning storage
- Using DMP with a SAN boot disk
- Configuring DMP for SAN booting
- Administering the root volume group (rootvg) under DMP control
- Extending an LVM rootvg that is enabled for DMP
- Quotas
- Using Veritas File System quotas
- File Change Log
- Section X. Reference
- Appendix A. Reverse path name lookup
- Appendix B. Tunable parameters
- Tuning the VxFS file system
- Methods to change Dynamic Multi-Pathing tunable parameters
- Tunable parameters for VxVM
- Methods to change Veritas Volume Manager tunable parameters
- Appendix C. Command reference
- Appendix D. Executive Order logging
About the Veritas File System File Change Log file
File Change Log records file system changes such as creates, links, unlinks, renaming, data appended, data overwritten, data truncated, extended attribute modifications, holes punched, and miscellaneous file property updates.
FCL stores changes in a sparse file in the file system namespace. The FCL file is located in mount_point/lost+found/changelog
. The FCL file behaves like a regular file, but some operations are prohibited. The standard system calls open
(2), lseek
(2), read
(2) and close
(2) can access the data in the FCL, while the write
(2), mmap
(2) and rename
(2) calls are not allowed.
Warning:
Although some standard system calls are currently supported, the FCL file might be pulled out of the namespace in future VxFS release and these system calls may no longer work. It is recommended that all new applications be developed using the programmatic interface.
The FCL log file contains both the information about the FCL, which is stored in the FCL superblock, and the changes to files and directories in the file system, which is stored as FCL records.
See Veritas File System File Change Log programmatic interface.
In the 4.1 release, the structure of the File Change Log file was exposed through the /opt/VRTS/include/sys/fs/fcl.h
header file. In this release, the internal structure of the FCL file is opaque. The recommended mechanism to access the FCL is through the API described by the /opt/VRTSfssdk/7.0.0.000/include/vxfsutil.h
header file.
The /opt/VRTS/include/sys/fs/fcl.h
header file is included in this release to ensure that applications accessing the FCL with the 4.1 header file do not break. New applications should use the new FCL API described in /opt/VRTSfssdk/7.0.0.000/include/vxfsutil.h
. Existing applications should also be modified to use the new FCL API.
To provide backward compatibility for the existing applications, this release supports multiple FCL versions. Users have the flexibility of specifying the FCL version for new FCLs. The default FCL version is 4.
See the fcladm
(1M) man page.