Infrastructure Software

Recently capped the ZFS arcsize to 1G and after that facing performance degrade. Below is the arc size summary. Is it due to it? Is these values looks good?

root@xxxxx# ./arc_summary.pl
System Memory:
Physical RAM: 32168 MB
Free Memory : 12858 MB
LotsFree: 502 MB

ZFS Tunables (/etc/system):
set zfs:zfs_arc_min = 536870912
set zfs:zfs_arc_max = 1073741824

ARC Size:
Current Size: 1024 MB (arcsize)
Target Size (Adaptive): 1024 MB (c)
Min Size (Hard Limit): 512 MB (zfs_arc_min)
Max Size (Hard Limit): 1024 MB (zfs_arc_max)

ARC Size Breakdown:
Most Recently Used Cache Size: 100% 1024 MB (p)
Most Frequently Used Cache Size: 0% 0 MB (c-p)

ARC Efficency:
Cache Access Total: 1561586074
Cache Hit Ratio: 63% 989868770 [Defined State for buffer]
Cache Miss Ratio: 36% 571717304 [Undefined State for Buffer]
REAL Hit Ratio: 57% 902266992 [MRU/MFU Hits Only]

Data Demand Efficiency: 87%
Data Prefetch Efficiency: 15%

CACHE HITS BY CACHE LIST:
Anon: 2% 25767928 [ New Customer, First Cache Hit ]
Most Recently Used: 48% 483324813 (mru) [ Return Customer ]
Most Frequently Used: 42% 418942179 (mfu) [ Frequent Customer ]
Most Recently Used Ghost: 5% 56475843 (mru_ghost) [ Return Customer Evicted, Now Back ]
Most Frequently Used Ghost: 0% 5358007 (mfu_ghost) [ Frequent Customer Evicted, Now Back ]
CACHE HITS BY DATA TYPE:
Demand Data: 35% 352951714
Prefetch Data: 8% 88499481
Demand Metadata: 53% 533008980
Prefetch Metadata: 1% 15408595
CACHE MISSES BY DATA TYPE:
Demand Data: 8% 49456114
Prefetch Data: 84% 480835089
Demand Metadata: 3% 20283710
Prefetch Metadata: 3% 21142391
---------------------------------------------
root@xxxxx# kstat -m zfs
module: zfs instance: 0
name: arcstats class: misc
c 1073741824
c_max 1073741824
c_min 536870912
crtime 63.365458
data_size 1024267264
deleted 538471458
demand_data_hits 352972102
demand_data_misses 49456561
demand_metadata_hits 533072382
demand_metadata_misses 20284002
evict_l2_cached 0
evict_l2_eligible 3996707256320
evict_l2_ineligible 1622412401152
evict_skip 700357539324
hash_chain_max 7
hash_chains 14289
hash_collisions 145136629
hash_elements 133566
hash_elements_max 247911
hdr_size 27198096
hits 989962896
l2_abort_lowmem 0
l2_cksum_bad 0
l2_evict_lock_retry 0
l2_evict_reading 0
l2_feeds 0
l2_free_on_write 0
l2_hdr_size 0
l2_hits 0
l2_io_error 0
l2_misses 0
l2_read_bytes 0
l2_rw_clash 0
l2_size 0
l2_write_bytes 0
l2_writes_done 0
l2_writes_error 0
l2_writes_hdr_miss 0
l2_writes_sent 0
memory_throttle_count 0
mfu_ghost_hits 5358007
mfu_hits 418994815
misses 571783495
mru_ghost_hits 56501170
mru_hits 483355968
mutex_miss 14204711
other_size 25673376
p 1073741824
prefetch_data_hits 88509816
prefetch_data_misses 480900525
prefetch_metadata_hits 15408596
prefetch_metadata_misses 21142407
recycle_miss 239284243
size 1077138736
snaptime 247915.3975403

module: zfs instance: 0
name: vdev_cache_stats class: misc
crtime 63.3654957
delegations 1406403
hits 3751966
misses 35800190
snaptime 247915.4001108

module: zfs instance: 0
name: zfetchstats class: misc
bogus_streams 0
colinear_hits 382948
colinear_misses 322805915
crtime 63.3634604
hits 470793292
misses 323188863
reclaim_failures 317205222
reclaim_successes 5600693
snaptime 247915.4007111
streams_noresets 281329975
streams_resets 746321
stride_hits 189463317
stride_misses 2657012