File systems and storage
LVM enchancements
Solid®-state disks (SSDs) are a very popular option for enterprise storage requirements. SSDs are unique in that they do not have any moving parts and thus perform at electronic speeds without mechanical delays (moving heads or spinning platters) associated with traditional spinning Hard Disk Drives (HDDs). Compared to traditional HDDs, the characteristics of SSDs enable a higher level of I/O performance in terms of greater throughput and lower response times for random I/O. These devices are ideal for applications that require high IOPS/GB and/or low response times.
AIX V7.1 includes enhanced support in the AIX Logical Volume Manager (LVM) for SSD. This includes the capability for LVM to restrict a volume group (VG) to only contain SSDs and the ability to report that a VG only contains SSDs. This feature is also available in AIX V6.1 with the 6100-06 Technology Level.
Hot files detection (HFD) in JFS2
In order to maximize the benefit of SSDs it is important to only place data on them that requires high throughput and low response times. This data is referred to as hot data or hot files. Typically a hot file can be described as a file that is read from or written too frequently. It could also be a file that is read from or written to in large chunks of data.
JFS2 Hot File Detection (HFD) enables the collection of statistics relating to file usage on a file system. The user interface to HFD is through programming functions only. HFD is implemented as a set of ioctl function calls. The enhancement is designed specifically so that application vendors can integrate this function into their product code. There is no AIX command line interface to the JFS2 HFD function or the statistics captured by HFD ioctl function calls. However, the filemon command can be used to provide global hot file detection for all file systems, logical volumes and physical disks on a system. The HFD mechanism is implemented as several ioctl calls.
WPAR - Workload Partitions
WPARs are virtualized software-based partitions running within an instance of AIX. They are available in
AIX V7.1 and AIX V6.1.
Versioned Workload Partitions (VWPAR)
A new product named AIX 5.2 Workload Partitions for AIX 7 supports the creation of an AIX 5.2 environment in a versioned workload partition (VWPAR). Applications running in a Versioned WPAR will interact with the legacy AIX environment in the user space.
Benefits
The capability to run an AIX 5.2 environment inside an AIX 7.1 WPAR has the following advantages:
- Ability to run AIX 5.2 on new hardware (POWER7 processor-based systems)
- Ability to extend service life for that old version of AIX
- Ability to run AIX 5.2 binary applications on new hardware without changing the user-space environment
Creation of a basic Versioned WPAR AIX 5.2
Creation of a Versioned WPAR requires the following steps, discussed in detail in the following sections:
- Creating an AIX 5.2 mksysb image
- Installing the support images for Versioned WPAR
- Creating the Versioned WPAR
- Starting the WPAR and its management
Processor interrupt disablement
AIX 6.1 TL6 and 7.1 provide a facility to quiesce (silent) external I/O interrupts on a given
set of logical processors. This helps reduce interrupt jitter that affects application performance.
Note: The changes are reflected dynamically without requiring a reboot of the system. Also, the changes are not persistent across reboots of the system.
# bindprocessor -q
The available processors are: 0 1
# cpuextintr_ctl -Q
The CPUs that have external interrupt enabled:
0 1
Distributed System Management
Starting with AIX 6.1 TL3 a new package is shipped with the base media called Distributed System Management (DSM). In AIX 7.1 this new DSM package replaces the Cluster Systems Management package (CSM), which is no longer available on AIX 7.1. Commands such as dcp and dsh are not available on AIX 7.1 without installing the DSM package, which is not installed by default but is on the base installation media. The DSM package is in the filesets dsm.core and dsm.dsh.
dsm.core - Distributed Systems Management Core
dsm.dsh - Distributed Systems Management Dsh
The new DSM programs found in the fileset dsm.core are:
dpasswd Creates an encrypted password file for an access point.
dkeyexch Exchanges default ssh keys with an access point.
dgetmacs Collects MAC address information from a machine.
dconsole Opens a remote console to a machine.
AIX binary compatibility
IBM guarantees that applications, whether written in-house or supplied by an application provider, will run on AIX 7.1 if they currently run on AIX 6.1 or AIX 5L—without recompilations or modification.
Improved performance using 1 TB segments
In AIX V7.1, 1 TB segments are an autonomic operating system feature designed to improve performance of 64-bit large memory applications. This enhancement optimizes performance when using shared memory regions (shmat/mmap). New restricted vmo options are available to change the operating system policy. A new VMM_CNTRL environment variable is available to alter per process behavior.
Kernel sockets application programming interface
To honor the increasing client and ISV demand to code environment- and solution-specific kernel extensions with socket level functionality, AIX V7.1 and AIX V6.1 with TL 6100-06 provide a documented kernel sockets application programming interface (API). The kernel service sockets API is packaged with other previously existing networking APIs in the base operating system 64-bit multiprocessor runtime fileset bos.mp64. Socket creation, binding, connection, listen, accept, get option, set option, Socket close etc
UNIX08 standard conformance
AIX V7.1 has implemented IEEE POSIX.1-200x The Open Group Base Specifications, Issue 7 standards in conformance with these standards. The Base Specifications volume contains general terms, concepts, and interfaces of this standard, including utility conventions and C-language header definitions. It also contains the definitions for system service APIs and subroutines, language-specific system services for the C programming language, and API issues, including portability, error handling, and error recovery.
Firmware-assisted dump
Firmware-assisted dump is now the default dump type in AIX V7.1
# oslevel -s
7100-00-00-0000
# sysdumpdev -l
primary /dev/lg_dumplv
secondary /dev/sysdumpnull
copy directory /var/adm/ras
forced copy flag TRUE
always allow dump FALSE
dump compression ON
type of dump fw-assisted
full memory dump disallow
#
Changing from traditional to firmware-assisted dump requires a reboot of the partition for the dump changes to take effect. sysdumpdev -t used to change from tradition to fw-assisted & vice versa.
Note: Firmware-assisted dump may be configured on POWER5™ or earlier based hardware, but all system dumps will operate as traditional dump. POWER6 is the minimum hardware platform required to support firmware-assisted dump.
User key enhancements
AIX 7.1 allows for configuring the number of user storage keys. It also allows a mode where all hardware keys are dedicated to user keys. This helps in developing large applications to use more user keys for application-specific needs.
smitty skctl
or skctl are used to control user storage keys.
Cluster Aware AIX
The Cluster Aware AIX (CAA) services help in creating and managing a cluster of AIX nodes to build a highly available and ideal architectural solution for a data center. IBM cluster products such as Reliable Scalable Cluster Technology (RSCT) and PowerHA use these services. CAA services can assist in the management and monitoring of an arbitrary set of nodes or in running a third-party cluster software.
Clusterwide event management
Clusterwide storage naming service
Clusterwide command distribution
Clusterwide communication
mkcluster, chcluster, rmcluster, lscluster, clcmd
Cluster aware perfstat library interfaces
The perfstat application programming interface (API) is a collection of C programming language subroutines that execute in the user space and use the perfstat kernel extension to extract various AIX performance metrics.
Beginning with AIX V7.1 and AIX 6.1 TL06, the existing perfstat library is enhanced to support performance data collection and analysis for a single node or multiple nodes in a cluster. The enhanced perfstat library provides APIs to obtain performance metrics related to processor, memory, I/O, and others to provide performance statistics about a node in a cluster.
Note: The perfstat_config (PERFSTAT_ENABLE | PERFSTAT_CLUSTER_STATS, NULL) must be used to enable the remote node statistics collection (available only in a cluster environment). Once node-related performance data is collected, perfstat_config (PERFSTAT_DISABLE | PERFSTAT_CLUSTER_STATS, NULL) must be used to disable collection of node or cluster statistics.
