Hi all,
I am trying to figure out why a new server i have configured is getting a hit ratio of around 53% and what i could do to improve it. Please note FreeNAS is virtualised (i know this isn't recommended).
System specs:
I have double checked configuration and all are the same.
arc_summary results
Happy to provide any additional information required.
Cheers
I am trying to figure out why a new server i have configured is getting a hit ratio of around 53% and what i could do to improve it. Please note FreeNAS is virtualised (i know this isn't recommended).
System specs:
- Server RAX XS8-2260
- 2 vCPU
- 48GB RAM
- 28TB pool in mirror
- Freenas installed onto a Sata DOM and mirrored
- PCIE SSD 400gb set as slog
- Intel X550T Dual 10gb NIC
- Server is used to store various types of files, documents, zip files, videos of varying sizes and accessed by upto 30 people at random times
- Hosts VMs and uses NFS
I have double checked configuration and all are the same.
arc_summary results
Code:
root@FREENAS1LAF:~ # arc_summary.py System Memory: 0.06% 26.62 MiB Active, 1.16% 557.04 MiB Inact 69.87% 32.66 GiB Wired, 0.00% 0 Bytes Cache 28.84% 13.48 GiB Free, 0.07% 31.99 MiB Gap Real Installed: 48.00 GiB Real Available: 99.92% 47.96 GiB Real Managed: 97.46% 46.74 GiB Logical Total: 48.00 GiB Logical Used: 70.78% 33.97 GiB Logical Free: 29.22% 14.03 GiB Kernel Memory: 370.00 MiB Data: 89.65% 331.72 MiB Text: 10.35% 38.28 MiB Kernel Memory Map: 46.74 GiB Size: 67.61% 31.61 GiB Free: 32.39% 15.14 GiB Page: 1 ------------------------------------------------------------------------ ARC Summary: (HEALTHY) Storage pool Version: 5000 Filesystem Version: 5 Memory Throttle Count: 0 ARC Misc: Deleted: 7.64m Mutex Misses: 4.33k Evict Skips: 4.33k ARC Size: 67.64% 30.94 GiB Target Size: (Adaptive) 92.43% 42.28 GiB Min Size (Hard Limit): 12.50% 5.72 GiB Max Size (High Water): 8:1 45.74 GiB ARC Size Breakdown: Recently Used Cache Size: 80.00% 33.83 GiB Frequently Used Cache Size: 20.00% 8.46 GiB ARC Hash Breakdown: Elements Max: 891.08k Elements Current: 48.98% 436.47k Collisions: 1.22m Chain Max: 4 Chains: 11.26k Page: 2 ------------------------------------------------------------------------ ARC Total accesses: 19.46m Cache Hit Ratio: 53.76% 10.46m Cache Miss Ratio: 46.24% 9.00m Actual Hit Ratio: 47.71% 9.28m Data Demand Efficiency: 64.57% 12.96m Data Prefetch Efficiency: 24.73% 5.69m CACHE HITS BY CACHE LIST: Anonymously Used: 3.56% 372.58k Most Recently Used: 71.02% 7.43m Most Frequently Used: 17.73% 1.85m Most Recently Used Ghost: 4.42% 462.83k Most Frequently Used Ghost: 3.27% 341.89k CACHE HITS BY DATA TYPE: Demand Data: 80.02% 8.37m Prefetch Data: 13.46% 1.41m Demand Metadata: 6.30% 658.58k Prefetch Metadata: 0.22% 22.93k CACHE MISSES BY DATA TYPE: Demand Data: 51.04% 4.59m Prefetch Data: 47.64% 4.29m Demand Metadata: 1.27% 114.26k Prefetch Metadata: 0.05% 4.61k Page: 3 ------------------------------------------------------------------------ Page: 4 ------------------------------------------------------------------------ DMU Prefetch Efficiency: 98.80m Hit Ratio: 9.47% 9.36m Miss Ratio: 90.53% 89.44m Page: 5 ------------------------------------------------------------------------ Page: 6 ------------------------------------------------------------------------ ZFS Tunable (sysctl): kern.maxusers 3405 vm.kmem_size 50191597568 vm.kmem_size_scale 1 vm.kmem_size_min 0 vm.kmem_size_max 1319413950874 vfs.zfs.vol.immediate_write_sz 32768 vfs.zfs.vol.unmap_enabled 1 vfs.zfs.vol.recursive 0 vfs.zfs.vol.mode 2 vfs.zfs.sync_pass_rewrite 2 vfs.zfs.sync_pass_dont_compress 5 vfs.zfs.sync_pass_deferred_free 2 vfs.zfs.zio.dva_throttle_enabled 1 vfs.zfs.zio.exclude_metadata 0 vfs.zfs.zio.use_uma 1 vfs.zfs.zil_slog_limit 786432 vfs.zfs.cache_flush_disable 0 vfs.zfs.zil_replay_disable 0 vfs.zfs.version.zpl 5 vfs.zfs.version.spa 5000 vfs.zfs.version.acl 1 vfs.zfs.version.ioctl 7 vfs.zfs.debug 0 vfs.zfs.super_owner 0 vfs.zfs.immediate_write_sz 32768 vfs.zfs.min_auto_ashift 12 vfs.zfs.max_auto_ashift 13 vfs.zfs.vdev.queue_depth_pct 1000 vfs.zfs.vdev.write_gap_limit 4096 vfs.zfs.vdev.read_gap_limit 32768 vfs.zfs.vdev.aggregation_limit 131072 vfs.zfs.vdev.trim_max_active 64 vfs.zfs.vdev.trim_min_active 1 vfs.zfs.vdev.scrub_max_active 2 vfs.zfs.vdev.scrub_min_active 1 vfs.zfs.vdev.async_write_max_active 10 vfs.zfs.vdev.async_write_min_active 1 vfs.zfs.vdev.async_read_max_active 3 vfs.zfs.vdev.async_read_min_active 1 vfs.zfs.vdev.sync_write_max_active 10 vfs.zfs.vdev.sync_write_min_active 10 vfs.zfs.vdev.sync_read_max_active 10 vfs.zfs.vdev.sync_read_min_active 10 vfs.zfs.vdev.max_active 1000 vfs.zfs.vdev.async_write_active_max_dirty_percent60 vfs.zfs.vdev.async_write_active_min_dirty_percent30 vfs.zfs.vdev.mirror.non_rotating_seek_inc1 vfs.zfs.vdev.mirror.non_rotating_inc 0 vfs.zfs.vdev.mirror.rotating_seek_offset1048576 vfs.zfs.vdev.mirror.rotating_seek_inc 5 vfs.zfs.vdev.mirror.rotating_inc 0 vfs.zfs.vdev.trim_on_init 1 vfs.zfs.vdev.bio_delete_disable 0 vfs.zfs.vdev.bio_flush_disable 0 vfs.zfs.vdev.cache.bshift 16 vfs.zfs.vdev.cache.size 0 vfs.zfs.vdev.cache.max 16384 vfs.zfs.vdev.metaslabs_per_vdev 200 vfs.zfs.vdev.trim_max_pending 10000 vfs.zfs.txg.timeout 5 vfs.zfs.trim.enabled 1 vfs.zfs.trim.max_interval 1 vfs.zfs.trim.timeout 30 vfs.zfs.trim.txg_delay 32 vfs.zfs.space_map_blksz 4096 vfs.zfs.spa_min_slop 134217728 vfs.zfs.spa_slop_shift 5 vfs.zfs.spa_asize_inflation 24 vfs.zfs.deadman_enabled 0 vfs.zfs.deadman_checktime_ms 5000 vfs.zfs.deadman_synctime_ms 1000000 vfs.zfs.debug_flags 0 vfs.zfs.debugflags 0 vfs.zfs.recover 0 vfs.zfs.spa_load_verify_data 1 vfs.zfs.spa_load_verify_metadata 1 vfs.zfs.spa_load_verify_maxinflight 10000 vfs.zfs.ccw_retry_interval 300 vfs.zfs.check_hostid 1 vfs.zfs.mg_fragmentation_threshold 85 vfs.zfs.mg_noalloc_threshold 0 vfs.zfs.condense_pct 200 vfs.zfs.metaslab.bias_enabled 1 vfs.zfs.metaslab.lba_weighting_enabled 1 vfs.zfs.metaslab.fragmentation_factor_enabled1 vfs.zfs.metaslab.preload_enabled 1 vfs.zfs.metaslab.preload_limit 3 vfs.zfs.metaslab.unload_delay 8 vfs.zfs.metaslab.load_pct 50 vfs.zfs.metaslab.min_alloc_size 33554432 vfs.zfs.metaslab.df_free_pct 4 vfs.zfs.metaslab.df_alloc_threshold 131072 vfs.zfs.metaslab.debug_unload 0 vfs.zfs.metaslab.debug_load 0 vfs.zfs.metaslab.fragmentation_threshold70 vfs.zfs.metaslab.gang_bang 16777217 vfs.zfs.free_bpobj_enabled 1 vfs.zfs.free_max_blocks 18446744073709551615 vfs.zfs.no_scrub_prefetch 0 vfs.zfs.no_scrub_io 0 vfs.zfs.resilver_min_time_ms 3000 vfs.zfs.free_min_time_ms 1000 vfs.zfs.scan_min_time_ms 1000 vfs.zfs.scan_idle 50 vfs.zfs.scrub_delay 4 vfs.zfs.resilver_delay 2 vfs.zfs.top_maxinflight 32 vfs.zfs.delay_scale 500000 vfs.zfs.delay_min_dirty_percent 60 vfs.zfs.dirty_data_sync 67108864 vfs.zfs.dirty_data_max_percent 10 vfs.zfs.dirty_data_max_max 4294967296 vfs.zfs.dirty_data_max 4294967296 vfs.zfs.max_recordsize 1048576 vfs.zfs.zfetch.array_rd_sz 1048576 vfs.zfs.zfetch.max_idistance 67108864 vfs.zfs.zfetch.max_distance 8388608 vfs.zfs.zfetch.min_sec_reap 2 vfs.zfs.zfetch.max_streams 8 vfs.zfs.prefetch_disable 0 vfs.zfs.send_holes_without_birth_time 1 vfs.zfs.mdcomp_disable 0 vfs.zfs.nopwrite_enabled 1 vfs.zfs.dedup.prefetch 1 vfs.zfs.l2c_only_size 0 vfs.zfs.mfu_ghost_data_esize 13137477632 vfs.zfs.mfu_ghost_metadata_esize 0 vfs.zfs.mfu_ghost_size 13137477632 vfs.zfs.mfu_data_esize 6645604864 vfs.zfs.mfu_metadata_esize 161513472 vfs.zfs.mfu_size 6817051648 vfs.zfs.mru_ghost_data_esize 4865523712 vfs.zfs.mru_ghost_metadata_esize 0 vfs.zfs.mru_ghost_size 4865523712 vfs.zfs.mru_data_esize 25995336192 vfs.zfs.mru_metadata_esize 143064064 vfs.zfs.mru_size 26296689664 vfs.zfs.anon_data_esize 0 vfs.zfs.anon_metadata_esize 0 vfs.zfs.anon_size 1259008 vfs.zfs.l2arc_norw 1 vfs.zfs.l2arc_feed_again 1 vfs.zfs.l2arc_noprefetch 1 vfs.zfs.l2arc_feed_min_ms 200 vfs.zfs.l2arc_feed_secs 1 vfs.zfs.l2arc_headroom 2 vfs.zfs.l2arc_write_boost 8388608 vfs.zfs.l2arc_write_max 8388608 vfs.zfs.arc_meta_limit 12279463936 vfs.zfs.arc_free_target 84997 vfs.zfs.compressed_arc_enabled 1 vfs.zfs.arc_shrink_shift 7 vfs.zfs.arc_average_blocksize 8192 vfs.zfs.arc_min 6139731968 vfs.zfs.arc_max 49117855744
Happy to provide any additional information required.
Cheers
