Any disadvantage to a huge L2ARC?

[jenksdrummer]

Generally speaking, the larger the SSD, the more lifespan one can expect from it - for example, the 4TB WD Red M.2 2280 SN700...5.1PBW lifespan equates to a .87 Drive Writes-Per-Day rating over 5 years = 3.49TB/Day/5Years; I don't believe I could be capable to churning that much data.

Even the 2TB model is rated for 2.5PBW life; which is .68 Drive Writes Per Day over 5 years; or 1.36TBW/Day/5 Years. Still really high.

So, all this has me asking the question, is there's any negative impact to having a > 1TB Cache VDEV

My TrueNAS Core system has 256GB RAM. I could make a case for not using a cache VDEV; but it's there.

 

[rvassar]

The L2ARC will use memory for reference tables, etc... The question you should ask is: "Would my workload benefit from an L2ARC?"

That would require you to analyze your "L1ARC", aka the ARC data your system is already collecting. You can access it via the CLI / SSH using the command "arc_summary".

Example:

Code:

:~ % arc_summary

------------------------------------------------------------------------
ZFS Subsystem Report                            Sun Dec 03 20:55:59 2023
FreeBSD 13.1-RELEASE-p7                                    zpl version 5
Machine: (redacted) (amd64)                             spa version 5000

ARC status:                                                      HEALTHY
        Memory throttle count:                                         0

ARC size (current):                                    74.8 %   21.4 GiB
        Target size (adaptive):                        74.7 %   21.4 GiB
        Min size (hard limit):                         3.5 %  1021.5 MiB
        Max size (high water):                           28:1   28.7 GiB
        Most Frequently Used (MFU) cache size:         55.1 %   11.3 GiB
        Most Recently Used (MRU) cache size:           44.9 %    9.2 GiB
        Metadata cache size (hard limit):              75.0 %   21.5 GiB
        Metadata cache size (current):                 12.6 %    2.7 GiB
        Dnode cache size (hard limit):                 10.0 %    2.1 GiB
        Dnode cache size (current):                    18.6 %  408.9 MiB

ARC hash breakdown:
        Elements max:                                               1.3M
        Elements current:                              80.4 %       1.0M
        Collisions:                                                18.2M
        Chain max:                                                     6
        Chains:                                                   110.7k

ARC misc:
        Deleted:                                                   23.8M
        Mutex misses:                                                865
        Eviction skips:                                            14.8k
        Eviction skips due to L2 writes:                               0
        L2 cached evictions:                                     0 Bytes
        L2 eligible evictions:                                   2.3 TiB
        L2 eligible MFU evictions:                      0.3 %    5.9 GiB
        L2 eligible MRU evictions:                     99.7 %    2.3 TiB
        L2 ineligible evictions:                                 3.2 GiB

ARC total accesses (hits + misses):                                 2.4G
        Cache hit ratio:                               99.6 %       2.4G
        Cache miss ratio:                               0.4 %      10.0M
        Actual hit ratio (MFU + MRU hits):             99.6 %       2.4G
        Data demand efficiency:                        98.6 %     317.5M
        Data prefetch efficiency:                      12.7 %     731.9k

Cache hits by cache type:
        Most frequently used (MFU):                    96.2 %       2.3G
        Most recently used (MRU):                       3.8 %      90.7M
        Most frequently used (MFU) ghost:             < 0.1 %     141.1k
        Most recently used (MRU) ghost:               < 0.1 %     267.6k

Cache hits by data type:
        Demand data:                                   13.1 %     312.9M
        Prefetch data:                                < 0.1 %      92.9k
        Demand metadata:                               86.9 %       2.1G
        Prefetch metadata:                              0.1 %       1.4M

Cache misses by data type:
        Demand data:                                   46.1 %       4.6M
        Prefetch data:                                  6.4 %     639.0k
        Demand metadata:                               42.4 %       4.2M
        Prefetch metadata:                              5.0 %     502.9k

DMU prefetch efficiency:                                          282.3M
        Hit ratio:                                      1.6 %       4.6M
        Miss ratio:                                    98.4 %     277.7M

L2ARC not detected, skipping section

 

[jenksdrummer]

Not sure how to interpret these results?

Code:

arc_summary

------------------------------------------------------------------------
ZFS Subsystem Report                            Mon Dec 04 07:29:39 2023
FreeBSD 13.1-RELEASE-p7                                    zpl version 5
Machine:  (amd64)                       spa version 5000

ARC status:                                                      HEALTHY
        Memory throttle count:                                         0

ARC size (current):                                    96.9 %  222.8 GiB
        Target size (adaptive):                        96.9 %  222.8 GiB
        Min size (hard limit):                          3.5 %    8.0 GiB
        Max size (high water):                           28:1  230.0 GiB
        Most Frequently Used (MFU) cache size:         77.6 %  172.3 GiB
        Most Recently Used (MRU) cache size:           22.4 %   49.7 GiB
        Metadata cache size (hard limit):              75.0 %  172.5 GiB
        Metadata cache size (current):                  1.1 %    1.9 GiB
        Dnode cache size (hard limit):                 10.0 %   17.3 GiB
        Dnode cache size (current):                     1.1 %  197.1 MiB

ARC hash breakdown:
        Elements max:                                              11.4M
        Elements current:                              26.5 %       3.0M
        Collisions:                                                22.8M
        Chain max:                                                     7
        Chains:                                                   128.5k

ARC misc:
        Deleted:                                                   33.4M
        Mutex misses:                                              29.8k
        Eviction skips:                                              768
        Eviction skips due to L2 writes:                               0
        L2 cached evictions:                                     3.8 TiB
        L2 eligible evictions:                                  20.4 TiB
        L2 eligible MFU evictions:                     14.2 %    2.9 TiB
        L2 eligible MRU evictions:                     85.8 %   17.5 TiB
        L2 ineligible evictions:                                 4.7 GiB

ARC total accesses (hits + misses):                                 3.0G
        Cache hit ratio:                               99.4 %       3.0G
        Cache miss ratio:                               0.6 %      19.6M
        Actual hit ratio (MFU + MRU hits):             99.3 %       3.0G
        Data demand efficiency:                        91.2 %      90.2M
        Data prefetch efficiency:                       4.0 %      10.3M

Cache hits by cache type:
        Most frequently used (MFU):                    97.7 %       3.0G
        Most recently used (MRU):                       2.3 %      68.5M
        Most frequently used (MFU) ghost:             < 0.1 %       1.4M
        Most recently used (MRU) ghost:               < 0.1 %     616.4k

Cache hits by data type:
        Demand data:                                    2.7 %      82.2M
        Prefetch data:                                < 0.1 %     414.0k
        Demand metadata:                               95.9 %       2.9G
        Prefetch metadata:                              1.3 %      40.4M

Cache misses by data type:
        Demand data:                                   40.7 %       8.0M
        Prefetch data:                                 50.4 %       9.9M
        Demand metadata:                                5.5 %       1.1M
        Prefetch metadata:                              3.5 %     679.7k

DMU prefetch efficiency:                                           98.6M
        Hit ratio:                                     19.9 %      19.6M
        Miss ratio:                                    80.1 %      79.0M

L2ARC status:                                                    HEALTHY
        Low memory aborts:                                             7
        Free on write:                                             10.0k
        R/W clashes:                                                   0
        Bad checksums:                                                 0
        I/O errors:                                                    0

L2ARC size (adaptive):                                           1.5 TiB
        Compressed:                                    89.5 %    1.4 TiB
        Header size:                                  < 0.1 %  140.3 MiB
        MFU allocated size:                            92.4 %    1.3 TiB
        MRU allocated size:                             7.6 %  107.4 GiB
        Prefetch allocated size:                      < 0.1 %   11.3 MiB
        Data (buffer content) allocated size:          99.9 %    1.4 TiB
        Metadata (buffer content) allocated size:       0.1 %    1.0 GiB

L2ARC breakdown:                                                   19.6M
        Hit ratio:                                     15.0 %       2.9M
        Miss ratio:                                    85.0 %      16.6M
        Feeds:                                                      1.4M

L2ARC writes:
        Writes sent:                                    100 %     655.8k

L2ARC evicts:
        Lock retries:                                               1.7k
        Upon reading:                                                  0

Tunables:
        abd_scatter_enabled                                            1
        abd_scatter_min_size                                        4097
        allow_redacted_dataset_mount                                   0
        anon_data_esize                                                0
        anon_metadata_esize                                            0
        anon_size                                                7368192
        arc.average_blocksize                                       8192
        arc.dnode_limit                                                0
        arc.dnode_limit_percent                                       10
        arc.dnode_reduce_percent                                      10
        arc.evict_batch_limit                                         10
        arc.eviction_pct                                             200
        arc.grow_retry                                                 0
        arc.lotsfree_percent                                          10
        arc.max                                             246969000000
        arc.meta_adjust_restarts                                    4096
        arc.meta_limit                                                 0
        arc.meta_limit_percent                                        75
        arc.meta_min                                                   0
        arc.meta_prune                                             10000
        arc.meta_strategy                                              1
        arc.min                                                        0
        arc.min_prefetch_ms                                            0
        arc.min_prescient_prefetch_ms                                  0
        arc.p_dampener_disable                                         1
        arc.p_min_shift                                                0
        arc.pc_percent                                                 0
        arc.prune_task_threads                                         1
        arc.shrink_shift                                               0
        arc.sys_free                                                   0
        arc_free_target                                          1390487
        arc_max                                             246969000000
        arc_min                                                        0
        arc_no_grow_shift                                              5
        async_block_max_blocks                      18446744073709551615
        autoimport_disable                                             1
        btree_verify_intensity                                         0
        ccw_retry_interval                                           300
        checksum_events_per_second                                    20
        commit_timeout_pct                                             5
        compressed_arc_enabled                                         1
        condense.indirect_commit_entry_delay_ms                        0
        condense.indirect_obsolete_pct                                25
        condense.indirect_vdevs_enable                                 1
        condense.max_obsolete_bytes                           1073741824
        condense.min_mapping_bytes                                131072
        condense_pct                                                 200
        crypt_sessions                                                 0
        dbgmsg_enable                                                  1
        dbgmsg_maxsize                                           4194304
        dbuf.cache_shift                                               5
        dbuf.metadata_cache_max_bytes               18446744073709551615
        dbuf.metadata_cache_shift                                      6
        dbuf_cache.hiwater_pct                                        10
        dbuf_cache.lowater_pct                                        10
        dbuf_cache.max_bytes                        18446744073709551615
        dbuf_state_index                                               0
        ddt_data_is_special                                            1
        deadman.checktime_ms                                       60000
        deadman.enabled                                                1
        deadman.failmode                                            wait
        deadman.synctime_ms                                       600000
        deadman.ziotime_ms                                        300000
        debug                                                          0
        debugflags                                                     0
        dedup.prefetch                                                 0
        default_bs                                                     9
        default_ibs                                                   15
        delay_min_dirty_percent                                       60
        delay_scale                                               500000
        dirty_data_max                                        4294967296
        dirty_data_max_max                                    4294967296
        dirty_data_max_max_percent                                    25
        dirty_data_max_percent                                        10
        dirty_data_sync_percent                                       20
        disable_ivset_guid_check                                       0
        dmu_object_alloc_chunk_shift                                   7
        dmu_offset_next_sync                                           1
        dmu_prefetch_max                                       134217728
        dtl_sm_blksz                                                4096
        embedded_slog_min_ms                                          64
        flags                                                          0
        fletcher_4_impl [fastest] scalar superscalar superscalar4 sse2 ssse3 avx                                                                            2 avx512f
        free_bpobj_enabled                                             1
        free_leak_on_eio                                               0
        free_min_time_ms                                            1000
        history_output_max                                       1048576
        immediate_write_sz                                         32768
        initialize_chunk_size                                    1048576
        initialize_value                            16045690984833335022
        keep_log_spacemaps_at_export                                   0
        l2arc.exclude_special                                          0
        l2arc.feed_again                                               1
        l2arc.feed_min_ms                                            200
        l2arc.feed_secs                                                1
        l2arc.headroom                                                 2
        l2arc.headroom_boost                                         200
        l2arc.meta_percent                                            33
        l2arc.mfuonly                                                  0
        l2arc.noprefetch                                               0
        l2arc.norw                                                     0
        l2arc.rebuild_blocks_min_l2size                       1073741824
        l2arc.rebuild_enabled                                          1
        l2arc.trim_ahead                                               0
        l2arc.write_boost                                       40000000
        l2arc.write_max                                         10000000
        l2arc_feed_again                                               1
        l2arc_feed_min_ms                                            200
        l2arc_feed_secs                                                1
        l2arc_headroom                                                 2
        l2arc_noprefetch                                               0
        l2arc_norw                                                     0
        l2arc_write_boost                                       40000000
        l2arc_write_max                                         10000000
        l2c_only_size                                                  0
        livelist.condense.new_alloc                                    0
        livelist.condense.sync_cancel                                  0
        livelist.condense.sync_pause                                   0
        livelist.condense.zthr_cancel                                  0
        livelist.condense.zthr_pause                                   0
        livelist.max_entries                                      500000
        livelist.min_percent_shared                                   75
        lua.max_instrlimit                                     100000000
        lua.max_memlimit                                       104857600
        max_async_dedup_frees                                     100000
        max_auto_ashift                                               14
        max_dataset_nesting                                           50
        max_log_walking                                                5
        max_logsm_summary_length                                      10
        max_missing_tvds                                               0
        max_missing_tvds_cachefile                                     2
        max_missing_tvds_scan                                          0
        max_nvlist_src_size                                            0
        max_recordsize                                           1048576
        metaslab.aliquot                                         1048576
        metaslab.bias_enabled                                          1
        metaslab.debug_load                                            0
        metaslab.debug_unload                                          0
        metaslab.df_alloc_threshold                               131072
        metaslab.df_free_pct                                           4
        metaslab.df_max_search                                  16777216
        metaslab.df_use_largest_segment                                0
        metaslab.find_max_tries                                      100
        metaslab.force_ganging                                  16777217
        metaslab.fragmentation_factor_enabled                          1
        metaslab.fragmentation_threshold                              70
        metaslab.lba_weighting_enabled                                 1
        metaslab.load_pct                                             50
        metaslab.max_size_cache_sec                                 3600
        metaslab.mem_limit                                            25
        metaslab.preload_enabled                                       1
        metaslab.preload_limit                                        10
        metaslab.segment_weight_enabled                                1
        metaslab.sm_blksz_no_log                                   16384
        metaslab.sm_blksz_with_log                                131072
        metaslab.switch_threshold                                      2
        metaslab.try_hard_before_gang                                  0
        metaslab.unload_delay                                         32
        metaslab.unload_delay_ms                                  600000
        mfu_data_esize                                      178334507520
        mfu_ghost_data_esize                                 99519249920
        mfu_ghost_metadata_esize                              4452267008
        mfu_ghost_size                                      103971516928
        mfu_metadata_esize                                     648274944
        mfu_size                                            185039536640
        mg.fragmentation_threshold                                    95
        mg.noalloc_threshold                                           0
        min_auto_ashift                                                9
        min_metaslabs_to_flush                                         1
        mru_data_esize                                       47987300864
        mru_ghost_data_esize                                 89944699904
        mru_ghost_metadata_esize                               275579904
        mru_ghost_size                                       90220279808
        mru_metadata_esize                                      16269312
        mru_size                                             53320974336
        multihost.fail_intervals                                      10
        multihost.history                                              0
        multihost.import_intervals                                    20
        multihost.interval                                          1000
        multilist_num_sublists                                         0
        no_scrub_io                                                    0
        no_scrub_prefetch                                              0
        nocacheflush                                                   0
        nopwrite_enabled                                               1
        obsolete_min_time_ms                                         500
        pd_bytes_max                                            52428800
        per_txg_dirty_frees_percent                                   30
        prefetch.array_rd_sz                                     1048576
        prefetch.disable                                               0
        prefetch.max_distance                                   67108864
        prefetch.max_idistance                                  67108864
        prefetch.max_sec_reap                                          2
        prefetch.max_streams                                           8
        prefetch.min_distance                                    4194304
        prefetch.min_sec_reap                                          1
        read_history                                                   0
        read_history_hits                                              0
        rebuild_max_segment                                      1048576
        rebuild_scrub_enabled                                          1
        rebuild_vdev_limit                                      33554432
        reconstruct.indirect_combinations_max                       4096
        recover                                                        0
        recv.queue_ff                                                 20
        recv.queue_length                                       16777216
        recv.write_batch_size                                    1048576
        removal_suspend_progress                                       0
        remove_max_segment                                      16777216
        resilver_disable_defer                                         0
        resilver_min_time_ms                                        3000
        scan_blkstats                                                  0
        scan_checkpoint_intval                                      7200
        scan_fill_weight                                               3
        scan_ignore_errors                                             0
        scan_issue_strategy                                            0
        scan_legacy                                                    0
        scan_max_ext_gap                                         2097152
        scan_mem_lim_fact                                             20
        scan_mem_lim_soft_fact                                        20
        scan_strict_mem_lim                                            0
        scan_suspend_progress                                          0
        scan_vdev_limit                                          4194304
        scrub_min_time_ms                                           1000
        send.corrupt_data                                              0
        send.no_prefetch_queue_ff                                     20
        send.no_prefetch_queue_length                            1048576
        send.override_estimate_recordsize                              0
        send.queue_ff                                                 20
        send.queue_length                                       16777216
        send.unmodified_spill_blocks                                   1
        send_holes_without_birth_time                                  1
        slow_io_events_per_second                                     20
        spa.asize_inflation                                           24
        spa.discard_memory_limit                                16777216
        spa.load_print_vdev_tree                                       0
        spa.load_verify_data                                           1
        spa.load_verify_metadata                                       1
        spa.load_verify_shift                                          4
        spa.slop_shift                                                 5
        space_map_ibs                                                 14
        special_class_metadata_reserve_pct                            25
        standard_sm_blksz                                         131072
        super_owner                                                    0
        sync_pass_deferred_free                                        2
        sync_pass_dont_compress                                        8
        sync_pass_rewrite                                              2
        sync_taskq_batch_pct                                          75
        top_maxinflight                                             1000
        traverse_indirect_prefetch_limit                              32
        trim.extent_bytes_max                                  134217728
        trim.extent_bytes_min                                      32768
        trim.metaslab_skip                                             0
        trim.queue_limit                                              10
        trim.txg_batch                                                32
        txg.history                                                  100
        txg.timeout                                                    5
        unflushed_log_block_max                                   131072
        unflushed_log_block_min                                     1000
        unflushed_log_block_pct                                      400
        unflushed_log_txg_max                                       1000
        unflushed_max_mem_amt                                 1073741824
        unflushed_max_mem_ppm                                       1000
        user_indirect_is_special                                       1
        validate_skip                                                  0
        vdev.aggregate_trim                                            0
        vdev.aggregation_limit                                   1048576
        vdev.aggregation_limit_non_rotating                       131072
        vdev.async_read_max_active                                     3
        vdev.async_read_min_active                                     1
        vdev.async_write_active_max_dirty_percent                     60
        vdev.async_write_active_min_dirty_percent                     30
        vdev.async_write_max_active                                    5
        vdev.async_write_min_active                                    1
        vdev.bio_delete_disable                                        0
        vdev.bio_flush_disable                                         0
        vdev.cache_bshift                                             16
        vdev.cache_max                                             16384
        vdev.cache_size                                                0
        vdev.def_queue_depth                                          32
        vdev.default_ms_count                                        200
        vdev.default_ms_shift                                         29
        vdev.file.logical_ashift                                       9
        vdev.file.physical_ashift                                      9
        vdev.initializing_max_active                                   1
        vdev.initializing_min_active                                   1
        vdev.max_active                                             1000
        vdev.max_auto_ashift                                          14
        vdev.min_auto_ashift                                           9
        vdev.min_ms_count                                             16
        vdev.mirror.non_rotating_inc                                   0
        vdev.mirror.non_rotating_seek_inc                              1
        vdev.mirror.rotating_inc                                       0
        vdev.mirror.rotating_seek_inc                                  5
        vdev.mirror.rotating_seek_offset                         1048576
        vdev.ms_count_limit                                       131072
        vdev.nia_credit                                                5
        vdev.nia_delay                                                 5
        vdev.queue_depth_pct                                        1000
        vdev.read_gap_limit                                        32768
        vdev.rebuild_max_active                                        3
        vdev.rebuild_min_active                                        1
        vdev.removal_ignore_errors                                     0
        vdev.removal_max_active                                        2
        vdev.removal_max_span                                      32768
        vdev.removal_min_active                                        1
        vdev.removal_suspend_progress                                  0
        vdev.remove_max_segment                                 16777216
        vdev.scrub_max_active                                          3
        vdev.scrub_min_active                                          1
        vdev.sync_read_max_active                                     10
        vdev.sync_read_min_active                                     10
        vdev.sync_write_max_active                                    10
        vdev.sync_write_min_active                                    10
        vdev.trim_max_active                                           2
        vdev.trim_min_active                                           1
        vdev.validate_skip                                             0
        vdev.write_gap_limit                                        4096
        version.acl                                                    1
        version.ioctl                                                 15
        version.module                         v2023072100-zfs_0eb787a7e
        version.spa                                                 5000
        version.zpl                                                    5
        vnops.read_chunk_size                                    1048576
        vol.mode                                                       2
        vol.recursive                                                  0
        vol.unmap_enabled                                              1
        wrlog_data_max                                        8589934592
        xattr_compat                                                   1
        zap_iterate_prefetch                                           1
        zevent.len_max                                               512
        zevent.retain_expire_secs                                    900
        zevent.retain_max                                           2000
        zfetch.max_distance                                     67108864
        zfetch.max_idistance                                    67108864
        zil.clean_taskq_maxalloc                                 1048576
        zil.clean_taskq_minalloc                                    1024
        zil.clean_taskq_nthr_pct                                     100
        zil.maxblocksize                                          131072
        zil.min_commit_timeout                                      5000
        zil.nocacheflush                                               0
        zil.replay_disable                                             0
        zil.slog_bulk                                             786432
        zio.deadman_log_all                                            0
        zio.dva_throttle_enabled                                       1
        zio.exclude_metadata                                           0
        zio.requeue_io_start_cut_in_line                               1
        zio.slow_io_ms                                             30000
        zio.taskq_batch_pct                                           80
        zio.taskq_batch_tpq                                            0
        zio.use_uma                                                    1

VDEV cache disabled, skipping section

ZIL committed transactions:                                        33.3M
        Commit requests:                                           12.8k
        Flushes to stable storage:                                 12.8k
        Transactions to SLOG storage pool:            0 Bytes          0
        Transactions to non-SLOG storage pool:       32.7 GiB     285.5k

That near-bottom line of "VDEV cache disabled, skipping section - seems...odd.

 

[jenksdrummer]

Guess I'll mention the system configuration.

Supermicro SYS-110P-WTR w/ 256GB ECC RAM, Xeon Silver 4310
Boot is 2x Supermicro SATA DOM 128GB; mirrored

Disks:
8x WD Red 4TB SATA SSD; RAIDZ2
2x Samsung PM9A3 1.92TB as Mirrored Metadata VDEV
Samsung 980 Pro 2TB M.2 w/ Heatsink as Cache

Pool details
recordsize=1M, special_small_slocks=512K, compression=zstd, checksum=SHA512

Autotune enabled
tuneable for powerd enabled, hiadaptive
tuneable for L2ARC persistence enabled

 

[HoneyBadger]

Frankly, given that you're using 8x SSDs as your pool devices, I'm struggling to find the advantage of a huge L2ARC here. You're already getting an extremely good hit ratio from your primary ARC of 256G, and your L2ARC is only hitting 15% of that tiny fraction you're missing.

Code:

ARC total accesses (hits + misses):                                 3.0G
        Cache hit ratio:                               99.4 %       3.0G

L2ARC breakdown:                                                   19.6M
        Hit ratio:                                     15.0 %       2.9M

You also have a (permanently attached) metadata mirror, which reduces the effective redundancy of your RAIDZ2 to single-disk failure tolerance (lose two pool SSDs and you're okay - lose both metadata PM9A3's and the pool's gone)

Can you elaborate a little more on what this pool is being used for that wasn't satisfied by an 8wZ2 of SSDs?

 

[jenksdrummer]

Use case? Insanity? It's a home lab SAN / file server / giant repo for my steam collection / etc.

 

[HoneyBadger]

With the special_small_blocks value there it's forcing all of the smaller files onto the metadata SSDs - as long as that's the expected behavior. :) Usually L2ARC doesn't make sense for an all-SSD setup is all.

 

[jenksdrummer]

With the special_small_blocks value there it's forcing all of the smaller files onto the metadata SSDs - as long as that's the expected behavior. :) Usually L2ARC doesn't make sense for an all-SSD setup is all.

Recordsize at 1M, most of my data is actually in the Z2 pool. I was aiming for a bit more balance; as just metadata alone would be less than1% and that just seems a waste for NVME ;)

Code:

zpool01                                         30.8T  8.88T  22.0T        -         -     1%    28%  1.00x    ONLINE  /mnt
  raidz2-0                                      29.1T  8.56T  20.5T        -         -     1%  29.4%      -    ONLINE
    gptid/68f3b133-85b9-11ee-9d5d-7cc255241120  3.64T      -      -        -         -      -      -      -    ONLINE
    gptid/68f1a0ce-85b9-11ee-9d5d-7cc255241120  3.64T      -      -        -         -      -      -      -    ONLINE
    gptid/68f91fd7-85b9-11ee-9d5d-7cc255241120  3.64T      -      -        -         -      -      -      -    ONLINE
    gptid/68e7c1da-85b9-11ee-9d5d-7cc255241120  3.64T      -      -        -         -      -      -      -    ONLINE
    gptid/68e45732-85b9-11ee-9d5d-7cc255241120  3.64T      -      -        -         -      -      -      -    ONLINE
    gptid/68dcdb7e-85b9-11ee-9d5d-7cc255241120  3.64T      -      -        -         -      -      -      -    ONLINE
    gptid/68f4cae1-85b9-11ee-9d5d-7cc255241120  3.64T      -      -        -         -      -      -      -    ONLINE
    gptid/68fb6bbc-85b9-11ee-9d5d-7cc255241120  3.64T      -      -        -         -      -      -      -    ONLINE
special                                             -      -      -        -         -      -      -      -  -
  mirror-1                                      1.73T   328G  1.41T        -         -     1%  18.5%      -    ONLINE
    gptid/68a82798-85b9-11ee-9d5d-7cc255241120  1.75T      -      -        -         -      -      -      -    ONLINE
    gptid/68a6ec22-85b9-11ee-9d5d-7cc255241120  1.75T      -      -        -         -      -      -      -    ONLINE
cache                                               -      -      -        -         -      -      -      -  -
  gptid/68b93d39-85b9-11ee-9d5d-7cc255241120    1.82T  1.38T   451G        -         -     0%  75.8%      -    ONLINE

I mean, I could probably push this a bit harder toward the special_small_blocks but I didn't want to set a custom record size outside what Core shows on the GUI. Something to experiment with on Scale ;)