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What are your ARC statistics?

Bidule0hm

Server Electronics Sorcerer
Joined
Aug 5, 2013
Messages
3,710
I'm just curious to see other member's ARC stats :)

I created a little script to help: http://pastebin.com/WBmxnikK

Just execute it, copy the result in your post (please copy the whole output (including the LIST tags), unless you'll break the bbcode...) and add your data type(s) in place of "Put your data type(s) here..." :)

Please note that this thread is meant to post the stats and not to ask about performance/problems regarding the ARC, I created this thread where you can ask your questions ;)

NB: Just to encourage posting so we have as most data as we can I'll give a thanks rating to each one who post his stats in this thread.

My stats:
  • Media, user documents
  • 1.76GiB / 7.44GiB (freenas-boot)
  • 3.50TiB / 21.8TiB (tank)
  • 11.76GiB (MRU: 10.84GiB, MFU: 971.10MiB) / 16.00GiB
  • Hit ratio -> 97.23% (higher is better)
  • Prefetch -> 52.11% (higher is better)
  • Hit MFU:MRU -> 85.20%:12.59% (higher ratio is better)
  • Hit MRU Ghost -> 0.30% (lower is better)
  • Hit MFU Ghost -> 0.18% (lower is better)

My stats another day (after a greater warm-up time):
  • Media, user documents
  • 3.22GiB / 7.44GiB (freenas-boot)
  • 3.86TiB / 21.8TiB (tank)
  • 11.87GiB (MRU: 11.29GiB, MFU: 771.47MiB) / 16.00GiB
  • Hit ratio -> 99.88% (higher is better)
  • Prefetch -> 43.00% (higher is better)
  • Hit MFU:MRU -> 99.18%:0.59% (higher ratio is better)
  • Hit MRU Ghost -> 0.00% (lower is better)
  • Hit MFU Ghost -> 0.03% (lower is better)

//

Old format:
  • Storage used size / Storage total size (as outputted by zpool list to have the same standard)
  • Data type(s) (media, VMs, ...)
  • ARC size / RAM size
  • ARC hit ratio
 
Last edited:

cyberjock

Moderator
Joined
Mar 25, 2012
Messages
19,148
  • Documents and Media
  • 3.23G
    12.0T
    42.3TB / 29.8G
    16.2T
    54.5TB
  • 22.72
    (Adaptive)GB (MRU: 21.33GB, MFU: 1.39GB) / 32.00GB
  • Hit ratio -> 82.94% (higher is better)
  • Prefetch -> 3.07% (higher is better)
  • Hit MFU:MRU -> 76.92%:17.86% (higher ratio is better)
  • Hit MRU Ghost -> 0.15% (lower is better)
  • Hit MFU Ghost -> 1.82% (lower is better)
 
Last edited:

Bidule0hm

Server Electronics Sorcerer
Joined
Aug 5, 2013
Messages
3,710
In fact I used the GUI reporting tab to get the stats but it's a good idea, I'll add the commands, thanks for the idea ;)

Edit: grrr, cyberjock edited his post so this one doesn't make any sense now... :rolleyes:
 
Last edited:

Ericloewe

Not-very-passive-but-aggressive
Moderator
Joined
Feb 15, 2014
Messages
16,108
3.54T / 10.48T
Backups/System Images; pictures and videos; documents; [some TV]
12G /16G
99.94% (oddly high, not that I'm complaining)
 

BigDave

FreeNAS Enthusiast
Joined
Oct 6, 2013
Messages
2,480
  • 2.10T / 16.2T
  • Media
  • 1.88G / 16GB
  • 95.6%
Sorry, can't edit mine cause I have not yet learned to run scripts
:(
 
Last edited:

Bidule0hm

Server Electronics Sorcerer
Joined
Aug 5, 2013
Messages
3,710
I just edited the first post to add some stats and a script ;)

Who is kind enough to edit his post with the new format? :D
 

cyberjock

Moderator
Joined
Mar 25, 2012
Messages
19,148
I just edited the first post to add some stats and a script ;)

Who is kind enough to edit his post with the new format? :D
Why did you sneak that zpool destroy in there!? Jerk! ;)
 

BigDave

FreeNAS Enthusiast
Joined
Oct 6, 2013
Messages
2,480
Last edited:

Ericloewe

Not-very-passive-but-aggressive
Moderator
Joined
Feb 15, 2014
Messages
16,108

cyberjock

Moderator
Joined
Mar 25, 2012
Messages
19,148
Deleted my other post. Script works fine. User error.

But the output from mine is a bit crazy....

  • Put your data type(s) here...
  • 3.23G
    12.0T
    42.3TB / 29.8G
    16.2T
    54.5TB
  • 22.72
    (Adaptive)GB (MRU: 21.33GB, MFU: 1.39GB) / 32.00GB
  • Hit ratio -> 82.94% (higher is better)
  • Prefetch -> 3.07% (higher is better)
  • Hit MFU:MRU -> 76.92%:17.86% (higher ratio is better)
  • Hit MRU Ghost -> 0.15% (lower is better)
  • Hit MFU Ghost -> 1.82% (lower is better)

LOTS of numbers there. I have more than 1 pool though and I don't think your script can handle that.

You want the truth!? YOU CAN'T HANDLE THE TRUTH!
 

Bidule0hm

Server Electronics Sorcerer
Joined
Aug 5, 2013
Messages
3,710
Why did you sneak that zpool destroy in there!? Jerk! ;)
I almost believed you... or not :D

You didn't put the pool name in argument (yeah, I know, it's not checked, but the script doesn't crash so... I'm just a little bit lazy right now...) and it handle only one pool (I've done it quick...). <-- edit: no need to put anything in argument now and it's multi-pool © capable :p

I'll probably edit the script later to add multi-pool capability ;) <-- edit: done :p² happy now? :p³

@BigDave no big deal :) But you should learn how to make and execute a script, mini-tuto:
  • Create a file and copy-paste the content of the pastebin in it, save, quit the editor
  • Make it executable chmod +x theNameOfYourFile
  • To execute it simply do ./theNameOfYourFile
  • NB: for the scripts we use the .sh extension by convention. Be careful to not execute any script found on the net without reading it before to ensure that there is no dangerous commands in it.
 
Last edited:
Joined
Nov 14, 2013
Messages
30
  • Media storage (Video, Music, Photo)
  • 5.99TB / 14.5TB (tank)
  • 11.50GB (MRU: 10.49GB, MFU: 1.01GB) / 16.00GB
  • Hit ratio -> 98.63% (higher is better)
  • Prefetch -> 37.94% (higher is better)
  • Hit MFU:MRU -> 97.16%:1.50% (higher ratio is better)
  • Hit MRU Ghost -> 0.04% (lower is better)
  • Hit MFU Ghost -> 0.50% (lower is better)
 

DifferentStrokes

FreeNAS Experienced
Joined
Jan 9, 2015
Messages
428
  • Jails, Backups, User Home Directories, Music, Movies
  • 4.01TB / 21.8TB (WD6REDS)
  • 1.99GB / 14.4GB (freenas-boot)
  • 23.21GB (MRU: 21.65GB, MFU: 1.59GB) / 32.00GB
  • Hit ratio -> 94.23% (higher is better)
  • Prefetch -> 32.54% (higher is better)
  • Hit MFU:MRU -> 78.11%:6.88% (higher ratio is better)
  • Hit MRU Ghost -> 0.17% (lower is better)
  • Hit MFU Ghost -> 0.50% (lower is better)
 

titan_rw

FreeNAS Experienced
Joined
Sep 1, 2012
Messages
591
Here's mine:

  • Mostly media / streaming
  • 15.4TB / 32.5TB (nas1pool)
  • 46.25GB (MRU: 35.56GB, MFU: 10.72GB) / 64.00GB
  • Hit ratio -> 99.16% (higher is better)
  • Prefetch -> 2.95% (higher is better)
  • Hit MFU:MRU -> 98.12%:1.58% (higher ratio is better)
  • Hit MRU Ghost -> 0.00% (lower is better)
  • Hit MFU Ghost -> 0.00% (lower is better)

98% of ARC hits on 23% of the overall ARC.
 

Fraoch

FreeNAS Experienced
Joined
Aug 14, 2014
Messages
395
  • Mac Time Machine backups, Linux backups, misc. files
  • 3.51GB / 58.5GB (freenas-boot)
  • 1.29TB / 7.25TB (volume1)
  • 9.37GB (MRU: 7.66GB, MFU: 6.79GB) / 16.00GB
  • Hit ratio -> 99.81% (higher is better)
  • Prefetch -> 55.53% (higher is better)
  • Hit MFU:MRU -> 98.98%:0.73% (higher ratio is better)
  • Hit MRU Ghost -> 0.00% (lower is better)
  • Hit MFU Ghost -> 0.00% (lower is better)

Yay! I have the highest hit MFU:MRU ratio!

Step 1: Achieve highest hit MFU:MRU ratio.
Step 2: ???
Step 3: PROFIT!
 

Ericloewe

Not-very-passive-but-aggressive
Moderator
Joined
Feb 15, 2014
Messages
16,108
Updated:


  • Backups/System Images; pictures and videos; documents; [some TV]
  • 5.32TB / 16.2TB (Bender)
  • 2.55GB / 14.4GB (freenas-boot)
  • 11.64GB (MRU: 10.26GB, MFU: 1.42GB) / 16.00GB
  • Hit ratio -> 99.94% (higher is better)
  • Prefetch -> 14.25% (higher is better)
  • Hit MFU:MRU -> 73.76%:0.19% (higher ratio is better)
  • Hit MRU Ghost -> 0.01% (lower is better)
  • Hit MFU Ghost -> 0.01% (lower is better)
 

cyberjock

Moderator
Joined
Mar 25, 2012
Messages
19,148
Here's my updated info:

  • Both pools are documents/media stuff.
  • 3.23GB / 29.8GB (freenas-boot)
  • 12.0TB / 16.2TB (encrypted)
  • 42.3TB / 54.5TB (tank)
  • 23.16
    (Adaptive)GB (MRU: 21.74GB, MFU: 1.46GB) / 32.00GB
  • Hit ratio -> 83.95% (higher is better)
  • Prefetch -> 4.16% (higher is better)
  • Hit MFU:MRU -> 79.56%:15.44% (higher ratio is better)
  • Hit MRU Ghost -> 0.17% (lower is better)
  • Hit MFU Ghost -> 2.10% (lower is better)

My hit ratio is low because I've been doing nasty things to this server and haven't rebooted.

As a general rule, if your hit ratio is below 90%, you will likely benefit from more ARC. My prefetch is also horri-bad because I've been doing replication from the server all morning. ;)
 

Bidule0hm

Server Electronics Sorcerer
Joined
Aug 5, 2013
Messages
3,710
It's very interesting, there is several common values and ratios of values across everyone stats despite the variations in RAM and storage size but there also a few oddities (MRU size:MFU size ratio of Fraoch or the very low prefetch of titan_rw for example).

I wonder if it's correlated to the type of data stored (backups vs live data maybe?) or to anything else. Hard to tell without having more stats to see if there is a pattern but definitely interesting :)

@cyberjock it's unfortunate that you've martyrized your server (poor server... :D) because you've one pool almost full and it would be interesting to see if it impacts the ARC stats.

And what's the "(Adaptive)" after the ARC size doing here? nobody has it. Something special about your server?

"Yay! I have the highest hit MFU:MRU ratio!" nop, beated by Ericloewe :D

BTW Thanks for all your posts guys ;)
 
Last edited:

Fraoch

FreeNAS Experienced
Joined
Aug 14, 2014
Messages
395
My server is very very lightly loaded. Once an hour except overnight, a Mac does a Time Machine backup to it. At midnight, my primary Linux workstation does an rsync backup to it. There are some digital photos and some large recovery files (DVD .ISOs) but that's it. CPU usage is never above 10%.
"Yay! I have the highest hit MFU:MRU ratio!" nop, beated by Ericloewe :D
At first I was going to say "98.98%:0.73% > 73.76%:0.19%" but then I broke out my calculator. You're right, of course.:mad:

OK. Highest prefetch then. @Ericloewe's got my hit ratio beat by a tiny smidgen.:)
 
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