[Gluster-users] ZFS, ZIL and ARC

[Gandalf Corvotempesta]

2016-10-30 15:05 GMT+01:00 Lindsay Mathieson <lindsay.mathieson at gmail.com>:
> zfs get secondarycache,primarycache

# zfs get secondarycache,primarycache
NAME                                 PROPERTY        VALUE           SOURCE
pci-0000:01:00.0-scsi-0:0:1:0        secondarycache  all             default
pci-0000:01:00.0-scsi-0:0:1:0        primarycache    all             default
pci-0000:01:00.0-scsi-0:0:2:0        secondarycache  all             default
pci-0000:01:00.0-scsi-0:0:2:0        primarycache    all             default
pci-0000:01:00.0-scsi-0:0:2:0 at prova  secondarycache  all             default
pci-0000:01:00.0-scsi-0:0:2:0 at prova  primarycache    all             default
pci-0000:01:00.0-scsi-0:0:5:0        secondarycache  all             default
pci-0000:01:00.0-scsi-0:0:5:0        primarycache    all             default
pci-0000:01:00.0-scsi-0:0:5:0 at prova  secondarycache  all             default
pci-0000:01:00.0-scsi-0:0:5:0 at prova  primarycache    all             default


>
>
> Also
>
>     zpool status

# zpool status
  pool: pci-0000:01:00.0-scsi-0:0:1:0
 state: ONLINE
  scan: none requested
config:

NAME                             STATE     READ WRITE CKSUM
pci-0000:01:00.0-scsi-0:0:1:0    ONLINE       0     0     0
 pci-0000:01:00.0-scsi-0:0:1:0  ONLINE       0     0     0

errors: No known data errors

  pool: pci-0000:01:00.0-scsi-0:0:2:0
 state: ONLINE
  scan: scrub repaired 0 in 1h9m with 0 errors on Sun Oct 30 15:16:43 2016
config:

NAME                             STATE     READ WRITE CKSUM
pci-0000:01:00.0-scsi-0:0:2:0    ONLINE       0     0     0
 pci-0000:01:00.0-scsi-0:0:2:0  ONLINE       0     0     0
logs
 sdd1                           ONLINE       0     0     0
cache
 sdd2                           ONLINE       0     0     0

errors: No known data errors

  pool: pci-0000:01:00.0-scsi-0:0:5:0
 state: ONLINE
  scan: none requested
config:

NAME                             STATE     READ WRITE CKSUM
pci-0000:01:00.0-scsi-0:0:5:0    ONLINE       0     0     0
 pci-0000:01:00.0-scsi-0:0:5:0  ONLINE       0     0     0

errors: No known data errors

>     arc_summary.py -p 2
>
> for stats on your ARC cache

# ./arc_summary.py -p 2

------------------------------------------------------------------------
ZFS Subsystem Report Sun Oct 30 18:59:59 2016
ARC Total accesses: 128.27m
Cache Hit Ratio: 68.86% 88.33m
Cache Miss Ratio: 31.14% 39.95m
Actual Hit Ratio: 36.67% 47.04m

Data Demand Efficiency: 98.67% 26.13m
Data Prefetch Efficiency: 0.00% 21.68m

CACHE HITS BY CACHE LIST:
 Anonymously Used: 43.25% 38.20m
 Most Recently Used: 31.54% 27.86m
 Most Frequently Used: 21.72% 19.18m
 Most Recently Used Ghost: 3.38% 2.99m
 Most Frequently Used Ghost: 0.10% 92.49k

CACHE HITS BY DATA TYPE:
 Demand Data: 29.19% 25.79m
 Prefetch Data: 0.00% 9
 Demand Metadata: 23.99% 21.19m
 Prefetch Metadata: 46.81% 41.35m

CACHE MISSES BY DATA TYPE:
 Demand Data: 0.87% 348.07k
 Prefetch Data: 54.27% 21.68m
 Demand Metadata: 32.60% 13.02m
 Prefetch Metadata: 12.26% 4.90m


> and
>
>     arc_summary.py -p 3
>
> for your l2arc cache


# ./arc_summary.py -p 3

------------------------------------------------------------------------
ZFS Subsystem Report Sun Oct 30 19:00:28 2016
L2 ARC Summary: (HEALTHY)
Low Memory Aborts: 0
Free on Write: 2
R/W Clashes: 0
Bad Checksums: 0
IO Errors: 0

L2 ARC Size: (Adaptive) 3.58 GiB
Compressed: 92.54% 3.31 GiB
Header Size: 0.06% 2.25 MiB

L2 ARC Evicts:
Lock Retries: 0
Upon Reading: 0

L2 ARC Breakdown: 413.37k
Hit Ratio: 0.00% 9
Miss Ratio: 100.00% 413.36k
Feeds: 18.56k

L2 ARC Writes:
Writes Sent: 100.00% 2.31k