Tunables value parameter definitions

When you create a tunables file for the installer you can only use the parameters in the following list.

Prior to making any updates to the tunables, refer to the Veritas Storage Foundation and High Availability Solutions Tuning Guide for detailed information on product tunable ranges and recommendations .

Table: Supported tunable parameters describes the supported tunable parameters that can be specified in a tunables file.

Table: Supported tunable parameters

Tunable

Description

dmp_cache_open

(Veritas Dynamic Multi-Pathing) Whether the first open on a device performed by an array support library (ASL) is cached. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_daemon_count

(Veritas Dynamic Multi-Pathing) The number of kernel threads for DMP administrative tasks. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_delayq_interval

(Veritas Dynamic Multi-Pathing) The time interval for which DMP delays the error processing if the device is busy. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_fast_recovery

(Veritas Dynamic Multi-Pathing) Whether DMP should attempt to obtain SCSI error information directly from the HBA interface. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_health_time

(Veritas Dynamic Multi-Pathing) The time in seconds for which a path must stay healthy. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_log_level

(Veritas Dynamic Multi-Pathing) The level of detail to which DMP console messages are displayed. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_low_impact_probe

(Veritas Dynamic Multi-Pathing) Whether the low impact path probing feature is enabled. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_lun_retry_timeout

(Veritas Dynamic Multi-Pathing) The retry period for handling transient errors. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_monitor_fabric

(Veritas Dynamic Multi-Pathing) Whether the Event Source daemon (vxesd) uses the Storage Networking Industry Association (SNIA) HBA API. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_monitor_osevent

(Veritas Dynamic Multi-Pathing) Whether the Event Source daemon (vxesd) monitors operating system events. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_monitor_ownership

(Veritas Dynamic Multi-Pathing) Whether the dynamic change in LUN ownership is monitored. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_native_support

(Veritas Dynamic Multi-Pathing) Whether DMP does multi-pathing for native devices. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_path_age

(Veritas Dynamic Multi-Pathing) The time for which an intermittently failing path needs to be monitored before DMP marks it as healthy. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_pathswitch_blks_shift

(Veritas Dynamic Multi-Pathing) The default number of contiguous I/O blocks sent along a DMP path to an array before switching to the next available path. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_probe_idle_lun

(Veritas Dynamic Multi-Pathing) Whether the path restoration kernel thread probes idle LUNs. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_probe_threshold

(Veritas Dynamic Multi-Pathing) The number of paths will be probed by the restore daemon. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_restore_cycles

(Veritas Dynamic Multi-Pathing) The number of cycles between running the check_all policy when the restore policy is check_periodic. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_restore_interval

(Veritas Dynamic Multi-Pathing) The time interval in seconds the restore daemon analyzes the condition of paths. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_restore_policy

(Veritas Dynamic Multi-Pathing) The policy used by DMP path restoration thread. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_restore_state

(Veritas Dynamic Multi-Pathing) Whether kernel thread for DMP path restoration is started. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_retry_count

(Veritas Dynamic Multi-Pathing) The number of times a path reports a path busy error consecutively before DMP marks the path as failed. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_scsi_timeout

(Veritas Dynamic Multi-Pathing) The timeout value for any SCSI command sent via DMP. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_sfg_threshold

(Veritas Dynamic Multi-Pathing) The status of the subpaths failover group (SFG) feature. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

dmp_stat_interval

(Veritas Dynamic Multi-Pathing) The time interval between gathering DMP statistics. This tunable must be set after Veritas Dynamic Multi-Pathing is started.

max_diskq

(Veritas File System) Specifies the maximum disk queue generated by a single file. The installer sets only the system default value of max_diskq. Refer to the tunefstab(4) manual page for setting this tunable for a specified block device.

read_ahead

(Veritas File System) The 0 value disables read ahead functionality, the 1 value (default) retains traditional sequential read ahead behavior, and the 2 value enables enhanced read ahead for all reads. The installer sets only the system default value of read_ahead. Refer to the tunefstab(4) manual page for setting this tunable for a specified block device.

read_nstream

(Veritas File System) The number of parallel read requests of size read_pref_io that can be outstanding at one time. The installer sets only the system default value of read_nstream. Refer to the tunefstab(4) manual page for setting this tunable for a specified block device.

read_pref_io

(Veritas File System) The preferred read request size. The installer sets only the system default value of read_pref_io. Refer to the tunefstab(4) manual page for setting this tunable for a specified block device.

vol_checkpt_default

(Veritas File System) Size of VxVM storage checkpoints (sectors). This tunable requires system reboot to take effect.

vol_cmpres_enabled

(Veritas Volume Manager) Allow enabling compression for VERITAS Volume Replicator.

vol_cmpres_threads

(Veritas Volume Manager) Maximum number of compression threads for VERITAS Volume Replicator.

vol_default_iodelay

(Veritas Volume Manager) Time to pause between I/O requests from VxVM utilities (10ms units). This tunable requires system reboot to take effect.

vol_fmr_logsz

(Veritas Volume Manager) Maximum size of bitmap Fast Mirror Resync uses to track changed blocks (KBytes). This tunable requires system reboot to take effect.

vol_max_adminio_poolsz

(Veritas Volume Manager) Maximum amount of memory used by VxVM admin I/O's (bytes). This tunablle rquires system reboot to take effect.

vol_max_nmpool_sz

(Veritas Volume Manager) Maximum name pool size (bytes).

vol_max_rdback_sz

(Veritas Volume Manager) Storage Record readback pool maximum (bytes).

vol_max_wrspool_sz

(Veritas Volume Manager) Maximum memory used in clustered version of VERITAS Volume Replicator (bytes).

vol_maxio

(Veritas Volume Manager) Maximum size of logical VxVM I/O operations (sectors). This tunable requires system reboot to take effect.

vol_maxioctl

(Veritas Volume Manager) Maximum size of data passed into the VxVM ioctl calls (bytes). This tunable requires system reboot to take effect.

vol_maxparallelio

(Veritas Volume Manager) Number of I/O operations vxconfigd can request at one time. This tunable requires system reboot to take effect.

vol_maxspecialio

(Veritas Volume Manager) Maximum size of a VxVM I/O operation issued by an ioctl call (sectors). This tunable requires system reboot to take effect.

vol_min_lowmem_sz

(Veritas Volume Manager) Low water mark for memory (bytes).

vol_nm_hb_timeout

(Veritas Volume Manager) Veritas Volume Replicator timeout value (ticks).

vol_rvio_maxpool_sz

(Veritas Volume Manager) Maximum memory requested by VERITAS Volume Replicator (bytes).

vol_stats_enable

(Veritas Volume Manager) Enable VxVM I/O stat collection.

vol_subdisk_num

(Veritas Volume Manager) Maximum number of subdisks attached to a single VxVM plex. This tunable requires system reboot to take effect.

voldrl_max_drtregs

(Veritas Volume Manager) Maximum number of dirty VxVM regions that can exist on a non-sequential DRL. This tunable requires system reboot to take effect.

voldrl_max_seq_dirty

(Veritas Volume Manager) Maximum number of dirty regions in sequential mode. This tunable requires system reboot to take effect.

voldrl_min_regionsz

(Veritas Volume Manager) Minimum size of a VxVM Dirty Region Logging (DRL) region (sectors). This tunable requires system reboot to take effect.

voldrl_volumemax_drtregs

(Veritas Volume Manager) Max per volume dirty regions in log-plex DRL.

voldrl_volumemax_drtregs_20

(Veritas Volume Manager) Max per volume dirty regions in DCO version 20.

voldrl_dirty_regions

(Veritas Volume Manager) Number of regions cached for DCO version 30.

voliomem_chunk_size

(Veritas Volume Manager) Size of VxVM memory allocation requests (bytes). This tunable requires system reboot to take effect.

voliomem_maxpool_sz

(Veritas Volume Manager) Maximum amount of memory used by VxVM (bytes). This tunable requires system reboot to take effect.

voliot_errbuf_dflt

(Veritas Volume Manager) Size of a VxVM error trace buffer (bytes). This tunable requires system reboot to take effect.

voliot_iobuf_default

(Veritas Volume Manager) Default size of a VxVM I/O trace buffer (bytes). This tunable requires system reboot to take effect.

voliot_iobuf_limit

(Veritas Volume Manager) Maximum total size of all VxVM I/O trace buffers (bytes). This tunable requires system reboot to take effect.

voliot_iobuf_max

(Veritas Volume Manager) Maximum size of a VxVM I/O trace buffer (bytes). This tunable requires system reboot to take effect.

voliot_max_open

(Veritas Volume Manager) Maximum number of VxVM trace channels available for vxtrace commands. This tunable requires system reboot to take effect.

volpagemod_max_memsz

(Veritas Volume Manager) Maximum paging module memory used by Instant Snapshots (Kbytes).

volraid_rsrtransmax

(Veritas Volume Manager) Maximum number of VxVM RAID-5 transient reconstruct operations in parallel. This tunable requires system reboot to take effect.

vxfs_mbuf

(Veritas File System) Maximum memory used for VxFS buffer cache. This tunable requires system reboot to take effect.

vxfs_ninode

(Veritas File System) Number of entries in the VxFS inode table. This tunable requires system reboot to take effect.

write_nstream

(Veritas File System) The number of parallel write requests of size write_pref_io that can be outstanding at one time. The installer sets only the system default value of write_nstream. Refer to the tunefstab(4) manual page for setting this tunable for a specified block device.

write_pref_io

(Veritas File System) The preferred write request size. The installer sets only the system default value of write_pref_io. Refer to the tunefstab(4) manual page for setting this tunable for a specified block device.