mattlach
Patron
- Joined
- Oct 14, 2012
- Messages
- 280
Hey all,
So in my reading I have come across many references to ARC being ~7/8 of total system RAM.
In my system (disregard sig below, system is in flux) I currently have one pool with two 6 disk RAIDz2 vdevs and a mirrored SLOG. See below:
Total system RAM is 72GB, but both in top and in the arc_summary.py output, by arc is only 51GB. If the 7/8 rule were true, I should be at 63GB.
Any idea why this is? See below for details (no idea why it is reporting 80GB total ram. Definitely only 72GB installed as verified by physical count and verified in BIOS and memtest86+
Thanks,
Matt
So in my reading I have come across many references to ARC being ~7/8 of total system RAM.
In my system (disregard sig below, system is in flux) I currently have one pool with two 6 disk RAIDz2 vdevs and a mirrored SLOG. See below:
Code:
pool: zfshome state: ONLINE scan: resilvered 1.28T in 10h9m with 0 errors on Mon Aug 25 05:36:39 2014 config: NAME STATE READ WRITE CKSUM zfshome ONLINE 0 0 0 raidz2-0 ONLINE 0 0 0 gptid/85faf71f-2b00-11e4-bc04-d8d3855ce4bc ONLINE 0 0 0 gptid/86d3925a-2b00-11e4-bc04-d8d3855ce4bc ONLINE 0 0 0 gptid/87a4d43b-2b00-11e4-bc04-d8d3855ce4bc ONLINE 0 0 0 gptid/887d5e7f-2b00-11e4-bc04-d8d3855ce4bc ONLINE 0 0 0 gptid/89409ac9-2b00-11e4-bc04-d8d3855ce4bc ONLINE 0 0 0 gptid/3db34343-2bff-11e4-b231-001517168acc ONLINE 0 0 0 raidz2-1 ONLINE 0 0 0 gptid/56fb015b-2bfc-11e4-be49-001517168acc ONLINE 0 0 0 gptid/576cde68-2bfc-11e4-be49-001517168acc ONLINE 0 0 0 gptid/57dbbac1-2bfc-11e4-be49-001517168acc ONLINE 0 0 0 gptid/584a4dcc-2bfc-11e4-be49-001517168acc ONLINE 0 0 0 gptid/58f4ec2f-2bfc-11e4-be49-001517168acc ONLINE 0 0 0 gptid/5a0a813f-2bfc-11e4-be49-001517168acc ONLINE 0 0 0 logs mirror-2 ONLINE 0 0 0 gptid/0053fa01-2bfd-11e4-be49-001517168acc ONLINE 0 0 0 gptid/007bf444-2bfd-11e4-be49-001517168acc ONLINE 0 0 0 errors: No known data errors
Total system RAM is 72GB, but both in top and in the arc_summary.py output, by arc is only 51GB. If the 7/8 rule were true, I should be at 63GB.
Any idea why this is? See below for details (no idea why it is reporting 80GB total ram. Definitely only 72GB installed as verified by physical count and verified in BIOS and memtest86+
Thanks,
Matt
Code:
System Memory: 0.24% 171.39 MiB Active, 0.13% 89.70 MiB Inact 76.50% 53.42 GiB Wired, 0.00% 1.12 MiB Cache 23.13% 16.16 GiB Free, 0.00% 752.00 KiB Gap Real Installed: 80.00 GiB Real Available: 89.97% 71.98 GiB Real Managed: 97.02% 69.84 GiB Logical Total: 80.00 GiB Logical Used: 79.69% 63.76 GiB Logical Free: 20.31% 16.24 GiB Kernel Memory: 593.01 MiB Data: 96.11% 569.96 MiB Text: 3.89% 23.05 MiB Kernel Memory Map: 67.61 GiB Size: 74.87% 50.61 GiB Free: 25.13% 16.99 GiB Page: 1 ------------------------------------------------------------------------ ARC Summary: (HEALTHY) Storage pool Version: 5000 Filesystem Version: 5 Memory Throttle Count: 0 ARC Misc: Deleted: 165.57m Recycle Misses: 2.37m Mutex Misses: 9.26k Evict Skips: 9.26k ARC Size: 74.10% 51.01 GiB Target Size: (Adaptive) 74.10% 51.00 GiB Min Size (Hard Limit): 12.50% 8.60 GiB Max Size (High Water): 8:1 68.84 GiB ARC Size Breakdown: Recently Used Cache Size: 93.75% 47.82 GiB Frequently Used Cache Size: 6.25% 3.19 GiB ARC Hash Breakdown: Elements Max: 1.56m Elements Current: 95.55% 1.49m Collisions: 64.60m Chain Max: 18 Chains: 310.34k Page: 2 ------------------------------------------------------------------------ ARC Total accesses: 283.21m Cache Hit Ratio: 69.78% 197.62m Cache Miss Ratio: 30.22% 85.59m Actual Hit Ratio: 68.76% 194.74m Data Demand Efficiency: 99.52% 105.98m Data Prefetch Efficiency: 3.08% 85.89m CACHE HITS BY CACHE LIST: Anonymously Used: 0.85% 1.68m Most Recently Used: 69.61% 137.57m Most Frequently Used: 28.93% 57.17m Most Recently Used Ghost: 0.26% 521.38k Most Frequently Used Ghost: 0.34% 679.21k CACHE HITS BY DATA TYPE: Demand Data: 53.37% 105.48m Prefetch Data: 1.34% 2.65m Demand Metadata: 45.17% 89.26m Prefetch Metadata: 0.12% 234.50k CACHE MISSES BY DATA TYPE: Demand Data: 0.59% 506.09k Prefetch Data: 97.26% 83.25m Demand Metadata: 2.07% 1.77m Prefetch Metadata: 0.08% 66.62k Page: 3 ------------------------------------------------------------------------ Page: 4 ------------------------------------------------------------------------ File-Level Prefetch: (HEALTHY)DMU Efficiency: 499.63m Hit Ratio: 98.21% 490.67m Miss Ratio: 1.79% 8.96m Colinear: 8.96m Hit Ratio: 0.02% 2.24k Miss Ratio: 99.98% 8.96m Stride: 409.58m Hit Ratio: 100.00% 409.58m Miss Ratio: 0.00% 2.06k DMU Misc: Reclaim: 8.96m Successes: 0.77% 68.63k Failures: 99.23% 8.89m Streams: 81.09m +Resets: 0.00% 1.95k -Resets: 100.00% 81.09m Bogus: 0 Page: 5 ------------------------------------------------------------------------ Page: 6 ------------------------------------------------------------------------ ZFS Tunable (sysctl): kern.maxusers 384 vm.kmem_size 74985517056 vm.kmem_size_scale 1 vm.kmem_size_min 0 vm.kmem_size_max 329853485875 vfs.zfs.l2c_only_size 0 vfs.zfs.mfu_ghost_data_lsize 46490845184 vfs.zfs.mfu_ghost_metadata_lsize 4209311232 vfs.zfs.mfu_ghost_size 50700287488 vfs.zfs.mfu_data_lsize 3118072320 vfs.zfs.mfu_metadata_lsize 163840 vfs.zfs.mfu_size 3131036160 vfs.zfs.mru_ghost_data_lsize 977477632 vfs.zfs.mru_ghost_metadata_lsize 3091430912 vfs.zfs.mru_ghost_size 4068908544 vfs.zfs.mru_data_lsize 50370951680 vfs.zfs.mru_metadata_lsize 476672 vfs.zfs.mru_size 50690304000 vfs.zfs.anon_data_lsize 0 vfs.zfs.anon_metadata_lsize 0 vfs.zfs.anon_size 36716544 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 18477943808 vfs.zfs.arc_meta_used 1240025272 vfs.zfs.arc_min 9238971904 vfs.zfs.arc_max 73911775232 vfs.zfs.dedup.prefetch 1 vfs.zfs.mdcomp_disable 0 vfs.zfs.nopwrite_enabled 1 vfs.zfs.zfetch.array_rd_sz 1048576 vfs.zfs.zfetch.block_cap 256 vfs.zfs.zfetch.min_sec_reap 2 vfs.zfs.zfetch.max_streams 8 vfs.zfs.prefetch_disable 0 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.write_to_degraded 0 vfs.zfs.mg_noalloc_threshold 0 vfs.zfs.mg_alloc_failures 9 vfs.zfs.condense_pct 200 vfs.zfs.metaslab.weight_factor_enable 0 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 10485760 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.gang_bang 131073 vfs.zfs.ccw_retry_interval 300 vfs.zfs.check_hostid 1 vfs.zfs.deadman_enabled 0 vfs.zfs.deadman_checktime_ms 5000 vfs.zfs.deadman_synctime_ms 1000000 vfs.zfs.recover 0 vfs.zfs.txg.timeout 5 vfs.zfs.max_auto_ashift 13 vfs.zfs.vdev.cache.bshift 16 vfs.zfs.vdev.cache.size 0 vfs.zfs.vdev.cache.max 16384 vfs.zfs.vdev.trim_on_init 1 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.write_gap_limit 4096 vfs.zfs.vdev.read_gap_limit 32768 vfs.zfs.vdev.aggregation_limit 131072 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.larger_ashift_minimal 0 vfs.zfs.vdev.bio_delete_disable 0 vfs.zfs.vdev.bio_flush_disable 0 vfs.zfs.vdev.trim_max_pending 64 vfs.zfs.vdev.trim_max_bytes 2147483648 vfs.zfs.cache_flush_disable 0 vfs.zfs.zil_replay_disable 0 vfs.zfs.sync_pass_rewrite 2 vfs.zfs.sync_pass_dont_compress 5 vfs.zfs.sync_pass_deferred_free 2 vfs.zfs.zio.use_uma 1 vfs.zfs.snapshot_list_prefetch 0 vfs.zfs.version.ioctl 3 vfs.zfs.version.zpl 5 vfs.zfs.version.spa 5000 vfs.zfs.version.acl 1 vfs.zfs.debug 0 vfs.zfs.super_owner 0 vfs.zfs.vol.mode 2 vfs.zfs.trim.enabled 1 vfs.zfs.trim.max_interval 1 vfs.zfs.trim.timeout 30 vfs.zfs.trim.txg_delay 32 Page: 7 ------------------------------------------------------------------------