There is a new option for chfs called logshuffle. This new feature allows AIX administrators to use chfs to convert or swap existing JFS2 file systems to either inline or external (outline) log devices. Description of the fast_lnk_recov attribute. You can refer to the disk and disk adapter tunable parameters reference here for more information on fast_lnk_recov. This is turned on by setting the fast_lnk_recov attribute on the fscsiX devices to "yes", instead of the default "no." In testing, IBM found a typical reduction from ~15 seconds to ~5 seconds for retrying the I/O on a different / # lsattr -Rl fscsi0 -a fast_lnk_recov yes / # lsattr -El fscsi3 -a fast_lnk_recovįast_lnk_recov no Quick I/O failure for FC link failure case / # chdev -l fscsi3 -a fast_lnk_recov=yes / # lsattr -El fscsi3 -a fast_lnk_recovįast_lnk_recov yes Quick I/O failure for FC link failure case True+ To facilitate the fast failover for FC adapters, the fast_lnk_recov attribute has been introduced to enable/disable this option with the fscsiX AIX device. In a non-MPIO environment, it is recommended that administrators do not enable this new feature and that the default settings are left unchanged. As a best practice, you should have an alternative path through another FC adapter to handle FC adapter hardware failure scenarios. This tunable parameter is only used for a Multiple Path I/O (MPIO) environment where another path to failover is available. This failover operation helps the SCSI device driver to switch I/O operations to alternative paths. When this feature is enabled the Fibre Channel SCSI protocol (fscsiX) driver quickly fails over I/O operations to the SCSI device driver when the host or storage link is down. The good news is you can enable this option concurrently, i.e., without an outage, using the “chdev -U” command. This new capability is disabled by default and needs to be enabled. The new feature allows AIX to fail I/O to alternative paths when link events are detected on either the host or target sides. ** Accelerators are not available for partitions in POWER9_base modeĪIX Fast Failover for Fibre Channel AdaptersĪIX 7.3 TL1 introduced support for 16Gbps and faster Fibre Channel (FC) adapters, including NPIV Virtual Fibre Channel (VFC) clients, to improve the time for I/O failover. Nx_accel_mask = 0 ** No accelerators available ** In this instance, NX GZIP-capable AIX system dumps would not be possible. In the next example, we notice that the accelerator is not available, confirming that our LPAR is not running in the correct processor mode. Nx_accel_mask = 1 GZIP accelerator available In the example below, we observe that the accelerator is available, confirming that our LPAR is running in the correct processor mode. Refer to the nxstat command reference here. Use this command to check for the availability of the NX GZIP accelerator. Just a reminder, you can confirm if your LPAR is running in the correct mode using nxstat -S. You can refer to the sysdumpdev command reference here. NX GZIP dump compression is only applicable to firmware-assisted type system dumps. N : Enables the Nest Accelerators (NX) GZIP accelerated dump compression. The system dump is compressed without using the NX GZIP. sysdumpdev: -n : Disables the Nest Accelerators (NX) GZIP dump compression. The -n flag disables the feature, while the -N flag enables NX GZIP compression. The AIX sysdumpdev command includes two new options for enabling and disabling NX GZIP dump compression. This type of dump is only supported with FWAD and not traditional AIX / # oslevel / # sysdumpdevĮnable NX GZIP TRUE AIX sysdumpdev Command The overall time require to capture an AIX system dump remains unchanged, but the dump compression time is improved. In this mode, the LPAR has access to the NX GZIP accelerator.īy using this hardware capability, the time required to compress an AIX system dump image can be reduced significantly. running in “POWER9” or “Power10” processor compatibility mode). This feature is enabled by default when your logical partition (LPAR) is configured to run in POWER9 or Power10 mode (i.e. The AIX Firmware Assisted Dump (FWAD) can now be compressed using the on-chip (POWER9 and later) Nest Accelerator (NX) GZIP compression accelerator. The AIX system dump facility has been enhanced to improve performance using hardware-accelerated compression on IBM POWER9 and Power10 systems. I wanted to take a moment to talk about some of the new enhancements that caught my attention with AIX 7.3 TL1. IBM AIX 7.3 TL1, IBM AIX 7.2 TL5, IBM AIX 7 Standard Edition, IBM AIX 7 Enterprise Edition 1.9, IBM Private Cloud Edition 1.9, and IBM Private Cloud Edition 1.9 with AIX 7 have been updated and enhanced.You can find the official list of announcements and “what’s new” information at the following links: Many new features and functions were delivered with this TL. In December 2022, AIX 7.3 Technology Level (TL) 1 became available.
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