-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


On Mon, 15 Feb 2010 16:20, 000.fbsd@ wrote:
Alexander Leidinger wrote:

[...]

kstat.zfs.misc.arcstats.c
kstat.zfs.misc.arcstats.c_min
kstat.zfs.misc.arcstats.c_max

c_max is vfs.zfs.arc_max, c_min is vfs.zfs.arc_min.

kstat.zfs.misc.arcstats.evict_skip
kstat.zfs.misc.arcstats.memory_throttle_count
kstat.zfs.misc.arcstats.size

I'm not very sure about size and c... both represent some kind of
current size, but they are not the same.


About the tuning I would recommend to depend upon a more human readable
representation. I've seen someone posting something like this, but I do
not know how it was generated (some kind of script, but I do not know
where to get it).

I think you are referring to this script:
http://cuddletech.com/arc_summary/
and its FreeBSD version
http://bitbucket.org/koie/arc_summary/changeset/dbe14d2cf52b/

It gives output like this:

# arc_summary.sh

System Memory:
        Physical RAM:  4978 MB
        Free Memory :  755 MB

ARC Size:
        Current Size:             1028 MB (arcsize)
        Target Size (Adaptive):   1028 MB (c)
        Min Size (Hard Limit):    50 MB (zfs_arc_min)
        Max Size (Hard Limit):    1205 MB (zfs_arc_max)

ARC Size Breakdown:
        Most Recently Used Cache Size:          93%    963 MB (p)
        Most Frequently Used Cache Size:         6%    65 MB (c-p)

ARC Efficency:
        Cache Access Total:             358720716
Cache Hit Ratio: 97% 350351031 [Defined State for buffer] Cache Miss Ratio: 2% 8369685 [Undefined State for Buffer]
        REAL Hit Ratio:       76%       272917080      [MRU/MFU Hits Only]

        Data Demand   Efficiency:    96%
        Data Prefetch Efficiency:    27%

       CACHE HITS BY CACHE LIST:
Anon: 22% 77179355 [ New Customer, First Cache Hit ] Most Recently Used: 45% 158252587 (mru) [ Return Customer ] Most Frequently Used: 32% 114664493 (mfu) [ Frequent Customer ] Most Recently Used Ghost: 0% 9777 (mru_ghost) [ Return Customer Evicted, Now Back ] Most Frequently Used Ghost: 0% 244819 (mfu_ghost) [ Frequent Customer Evicted, Now Back ]
       CACHE HITS BY DATA TYPE:
         Demand Data:                 1%        4375918
         Prefetch Data:               0%        150148
         Demand Metadata:            76%        267830502
         Prefetch Metadata:          22%        77994463
       CACHE MISSES BY DATA TYPE:
         Demand Data:                 1%        135956
         Prefetch Data:               4%        400434
         Demand Metadata:            73%        6177748
         Prefetch Metadata:          19%        1655547
---------------------------------------------


Another useful script is arcstat.pl from
http://blogs.sun.com/realneel/entry/zfs_arc_statistics
There are FreeBSD version floating around but I can't find a link to it, so I am sending it as attachment.

It would be nice to have some "standardized" scripts for monitoring & debugging ZFS issues attached to FreeBSD Wiki page about ZFS tuning. Then everebody will use the same scripts, same output format. It will be easier to compare results in discussions etc.

So if anybody of you have write permissions to Wiki, can you add those two scripts? (or make some better ;])

Understanding to tuning of ZFS is really hard with lack of documentation ;(

Miroslav Lachman


It is funny that you guys are all of a sudden talking about this, as I was just working on some modifications to the arc_summary.pl script for some better formatting and inclusion of kmem statistics.

My intent on the modifications is to make the output more usable to the whole community by revealing the relevant system information that can be included in an email to the lists for diagnosis by others.

Previously the output of the script was a little bit groggy, had long lines and did not include relevant "other" system information.

Currently I am working on cleaning up the code a little and moving the ZFS Tunable section to the bottom of the output where it will actually contain the values of the sysctl's instead of just being a blank list.

I would certainly appreciate any feedback I could get from this & other things you think might be relevant in its output.

Thanks for bringing this subject up.

As I make final modifications to the script I will keep the below URLs updated and welcome any bug reports or modification requests to me personally.

Here is the URLs:
http://jhell.googlecode.com/files/arc_summary.pl
http://jhell.googlecode.com/files/arc_summary.pl.asc

MD5 (arc_summary.pl) = bff13dcf119ff979d9aa52b3d8ae53b9
SHA256 (arc_summary.pl) = 
a29260946760a89614f888d53d0f188fb24bcd96acd5e0917604d494ed843ada
SIZE (arc_summary.pl) = 9453


Example output:
- ---------------------------------------------------------------------
System Summary
OS Revision:                                    199506
OS Release Date:                                703100
Hardware Platform:                              i386
Processor Architecture:                         i386
Storage pool Version:                           13
Filesystem Version:                             3

Kernel Memory Usage
TEXT:                           8950208 KiB,    8 MiB
DATA:                           206347264 KiB,  196 MiB
TOTAL:                          215297472 KiB,  205 MiB

FreeBSD 7.3-STABLE #0 r203819M Sun Feb 14 15:40:02 EST 2010 root
- ---------------------------------------------------------------------

ZFS ARC Summary Report

System Memory:
        Physical RAM:                           1009 MiB

ZFS Tunable (sysctl):
        vfs.zfs
        vm.kmem_size
        vm.kmem_size_max

ARC Size:
        Current Size:                           180 MiB (arcsize)
        Target Size (Adaptive):                 182 MiB (c)
        Min Size (Hard Limit):                  80 MiB (arc_min)
        Max Size (Hard Limit):                  480 MiB (arc_max)

ARC Size Breakdown:
        Recently Used Cache Size:       99%     181 MiB (p)
        Frequently Used Cache Size:      0%     1 MiB (c-p)

ARC Efficiency:
        Cache Access Total:                     32355906
        Cache Hit Ratio:                97%     31473948
        Cache Miss Ratio:                2%     881958
        Actual Hit Ratio:               89%     28801408

        Data Demand Efficiency:         99%
        Data Prefetch Efficiency:       44%

        CACHE HITS BY CACHE LIST:
          Anonymous:                     7%     2303558
          Most Recently Used:           13%     4157073 (mru)
          Most Frequently Used:         78%     24644335 (mfu)
          Most Recently Used Ghost:      0%     151893 (mru_ghost)
          Most Frequently Used Ghost:    0%     217089 (mfu_ghost)

        CACHE HITS BY DATA TYPE:
          Demand Data:                  73%     23206273
          Prefetch Data:                 0%     14877
          Demand Metadata:              14%     4611670
          Prefetch Metadata:            11%     3641128

        CACHE MISSES BY DATA TYPE:
          Demand Data:                  23%     206991
          Prefetch Data:                 2%     18760
          Demand Metadata:              53%     471124
          Prefetch Metadata:            20%     185083
- ---------------------------------------------------------------------

- --
 jhell

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.14 (FreeBSD)

iQEcBAEBAgAGBQJLefm5AAoJEJBXh4mJ2FR+2wYIAIpC6zPj4/ioak8TspN1blCV
LSNG/JXbqat9/e6EAulBSDaF81AyxKrUNMZxQqgNZ+fobhT4AY3odrlhUNbNX9UX
r8juktvG2kXhgpKmjYeP+HSM5KKbXZToBNx+sHwaTGKAybyTBNuhupmrbeGoOZVX
tmH6C/ZoOANtxmcHVOGDi/fViC1tTf396iBietaCGtKNJ5S6ziqa3DgJgzrJkSQI
2lYNKqcdusUPyxl22ug24Ifsp3TFn2fFYB22durAaXL9ZPHWruWVD2wQ02EPxdND
FmdheGS6OPKEG6Ph2ARTuJpJLZCPoN2EQJivkXI6N2WgsK+QRuZhuylVzDvu/3A=
=SSRg
-----END PGP SIGNATURE-----
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"

Reply via email to