mastering_zfs/ch06

ch06

dz / mastering_zfs / ch06

Summary

Chapter 6: Disk Space management

Node Tree

Nodes

reading_zfs_disk_usage
content reading zfs disk usage
children referenced_data, AVAIL

AVAIL
content AVAIL
parents reading_zfs_disk_usage

REFER
content REFER
parents referenced_data

referenced_data
content Referenced Data
children stuff_in_fs_or_dataset (description), REFER, exclues_snaps_clones_descendents, multiple_datasets_same_data
parents prop_refreservation, reading_zfs_disk_usage

stuff_in_fs_or_dataset
content Stuff tha texists within filesystem or dataset
parents referenced_data

multiple_datasets_same_data
content Multiple datasets can refer to the same data
parents referenced_data

freeing_space
content Freeing Space
children remove_large_files_older_snaps, zfs_ops_free_async, deleting_files_doesnt_free_space, freeing_property

freeing_property
content Freeing property
parents freeing_space

deleting_files_doesnt_free_space
content Deleting files doesn't enduing freeing space
children snapshots_metadata
parents freeing_space

snapshots_metadata
content Snapshots metadata
parents deleting_files_doesnt_free_space

zfs_ops_free_async
content ZFS operations free space asynchronously
parents freeing_space

remove_large_files_older_snaps
content Remove larger files by removing older snapshots
parents freeing_space

disk_space_details
content Disk space details
children see_where_disk_space_went, USED, USEDBYSNAP, USEDCHILD, USEDDS, pool_space_usage

USED
content USED
parents disk_space_details

zfs_cli
content zfs
children zfs_list

zfs_list
content list
children zroot, dash_o
parents zfs_cli

pool_space_usage
content Pool space usage
children zroot, df_incorrect, includes_space_for_parity
parents disk_space_details

USEDBYSNAP
content USEDBYSNAP
parents disk_space_details

dash_o
content -o
parents see_where_disk_space_went, zfs_list

see_where_disk_space_went
content See where disk space went
children dash_o
parents disk_space_details

zroot
content zroot
parents zfs_list, pool_space_usage

USEDCHILD
content USEDCHILD
parents disk_space_details

USEDDS
content USEDDS
parents disk_space_details

df_incorrect
content df utility gives incorrect answers about ZFS
parents pool_space_usage

includes_space_for_parity
content Includes space required for parity information
parents pool_space_usage

limiting_dataset_size
content Limiting dataset sizes
children quota, reservation

quota
content quota
children quota_properties, setting_quotas, user_group_quotas, viewing_quotas, dataset_quotas, exceeded_quotas, max_amt_space (description)
parents limiting_dataset_size

reservation
content Reservation
children reservation_properties, setting_removing, viewing, dictates_amt_space_for_dataset (description)
parents limiting_dataset_size

reservation_properties
content Properties
children prop_refreservation, prop_reservation, quota_properties (similar)
parents reservation

dictates_amt_space_for_dataset
content Dictates amt of space set aside for dataset
parents reservation

prop_reservation
content reservation
children set_none_to_remove, violating_res_yields_error, includes_snaps_child_datasets
parents reservation_properties

prop_refreservation
content refreservation
children referenced_data
parents reservation_properties

violating_res_yields_error
content Violating reservation property generates out-of-space error.
parents prop_reservation

includes_snaps_child_datasets
content includes snapshots, child datasets, etc
parents prop_reservation

exclues_snaps_clones_descendents
content Exclues snapshots, clones, other descendents
parents referenced_data

viewing
content Viewing
parents reservation

setting_removing
content setting/removing
children set_none_to_remove
parents reservation

set_none_to_remove
content Set to "none" to remove
parents setting_removing, prop_reservation

max_amt_space
content Max amount of space that a dataset, user, or usergroup may see.
parents quota

dataset_quotas
content Dataset Quotas
parents quota

setting_quotas
content Setting Quotas
parents quota

user_group_quotas
content User/Group quotas
parents quota

viewing_quotas
content Viewing
parents quota

exceeded_quotas
content Exceeded Quotas
parents quota

quota_properties
content Properties
children prop_quota, prop_refquota
parents reservation_properties, quota

prop_quota
content Quota
parents quota_properties

prop_refquota
content Refquota
parents quota_properties

zfs_compression
content ZFS compression
children comp_algorithms, comp_properties, enabling

enabling
content enabling
children compression_prop
parents zfs_compression

compression_prop
content Compression Property
children use_lz4_almost_always
parents enabling

use_lz4_almost_always
content Use lz4 compression in almost all cases
parents compression_prop

comp_algorithms
content algorithms
children zle, gzip, lz4, lzjb
parents zfs_compression

lzjb
content lzjb
children quick_compress_modest_ratio, default_algo, designed_for_filesystems
parents comp_algorithms

default_algo
content Default compression algorithm
parents lzjb

designed_for_filesystems
content Specifically designed for filesystem usage
parents lzjb

quick_compress_modest_ratio
content Quick compression/decompression. Modest compression ratio.
parents lzjb

lz4
content lz4
children more_cpu_than_lz4 (more cpu, but can be more effective), newer_faster
parents comp_algorithms

newer_faster
content newer, faster
parents lz4

zle
content zle
children compress_string_of_zeros
parents comp_algorithms

compress_string_of_zeros
content Compresses strings of zeros
parents zle

gzip
content gzip
children 9_compression_levels, more_cpu_than_lz4
parents comp_algorithms

more_cpu_than_lz4
content more cpu than lz4, but can be more effective
parents gzip, lz4

9_compression_levels
content 9 compression levels
children default_6
parents gzip

default_6
content Default level is 6
parents 9_compression_levels

comp_properties
content Properties
children compression_scenarios, compressratio_refcompressratio, deactivating_comp, insight_into_compression, logical_referenced, logical_used
parents zfs_compression

insight_into_compression
content Offers insight into how ZFS is compressing data
parents comp_properties

deactivating_comp
content Deactivating
children comp_to_off (how to turn off)
parents comp_properties

comp_to_off
content set compression propertie to "off"
parents deactivating_comp

compressratio_refcompressratio
content compressratio/refcompressratio
parents comp_properties

logical_used
content logical used
children amt_of_uncomp (description)
parents comp_properties, compression_scenarios

amt_of_uncomp
content Amount of uncompressed data in dataset
parents logical_used

compression_scenarios
content Compression Scenarios
children logical_referenced, logical_used
parents comp_properties

logical_referenced
content Logical Referenced
children amt_reference_space_uncomp (description)
parents comp_properties, compression_scenarios

amt_reference_space_uncomp
content Amount of reference space uncompressed
parents logical_referenced

deduplication
content deuplication
children ddup_at_fs_level, dedup_files, disabling_ddup, does_not_improve_reads, effectiveness, enabling_ddup, memory_needs

ddup_at_fs_level
content ZFS deduplicates at filesystem block level
children smaller_blocks_impact, dedup_files, fs_block_exact_alignment
parents deduplication

dedup_files
content Deduplicates files
parents ddup_at_fs_level, deduplication

fs_block_exact_alignment
content Filesystem blocks must line up exactly
parents ddup_at_fs_level

smaller_blocks_impact
content Smaller blocks increase deduplication effectiveness as well as increasing memory requirements
parents ddup_at_fs_level

memory_needs
content Memory needs
children fs_block_ddup_size, memory_rule_of_thumb
parents deduplication

memory_rule_of_thumb
content approximately 1TB of data uses 5 gigs of RAM
parents memory_needs

fs_block_ddup_size
content one filesystem block on deduplicated system uses approximately 320 bytes of RAM
parents memory_needs

zdb
content zdb -b [pool] memory_needs
children zdb_dash_s, how_many_blocks_used

how_many_blocks_used
content How many blocks used?
parents zdb

effectiveness
content Effectiveness
children zdb_dash_s, can_improve_cache_hit_rates
parents deduplication

does_not_improve_reads
content Does not improve disk read speeds
parents deduplication

zdb_dash_s
content zdb -s
children how_well
parents zdb, effectiveness

how_well
content How well?
parents zdb_dash_s

can_improve_cache_hit_rates
content Can improve cache hit rates
parents effectiveness

enabling_ddup
content Enabling
children dedup_on
parents deduplication

dedup_on
content dedup = on
children dedup_off
parents enabling_ddup

disabling_ddup
content Disabling
children dedup_off
parents deduplication

dedup_off
content dedup = off
parents disabling_ddup, dedup_on