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Need help setting up SMART & ZFS Scrubs

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Nov 11, 2013
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#1
Hello everyone!

I need some help setting up ZFS Scrubs and SMART. I have read the documentation for both, but I don't fully understand how to best setup and schedule these two.

I have a HP Proliant Microserver N54L running two WD Red 3TB in a mirror, which has been going strong for about a month now. Pretty easy workload for the NAS, small environment with 4-5 users and mostly 1-2 actually using the NAS at once. However, there's not a lot of downtime where it's okay for the NAS to be unavailable, which is why I'm having some difficulty scheduling scrubs and SMART tests.

I want to perform both of these early monday mornings (02:00-06:00 preferably, but 00:00-08:00 is okay), as this is the only time guaranteed to be non-critical. Reading the documentation, the best schedule I could come up with was to run SMART (long self test) one monday a month and ZFS-scrubs the other three.

Firstly, If anyone has any input on my scheduling, that would be great. I have no clue how taxing these operations actually are, as I am quite new to all of this. Maybe it would be fine to run them during operational hours?

Second, how does one go about configuring for a schedule that specific? Is it even possible via the GUI? So far I have managed to make the NAS run a ZFS scrub every monday (but no specific time, so I guess it starts at midnight?), but I also have a SMART test scheduled for the same day, and since there is no "treshold days" setting for SMART tests, I guess that one is going to run every single monday too, at the exact time of the ZFS scrub?

Lastly, is there any downside to doing these tests, other than a performance decrease when they are being run?

Thankful for all help, since I am a bit lost here.
 
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#2
Scrubs can hurt performance. How much depends on a lot of factors. It can range from you never noticing(my situation) to the server not being able to do its designed function.

I'm sorry, but I won't go into detail on my setup because I've discussed this to death. But this is my configuration for what its worth. The situation is really complex so I recommend you either rigidly follow my schedule(recommended) or read up on all the stuff you should and shouldn't do and make up your own.

Scrubs: 1st and 15th, 10 day threshold, 0200, every month, every day of the week, and enabled.

SMART monitoring: check interval = 30 minutes, difference = 0, informational = 0, critical = 40. For email to report I do my email address.(Do make sure you can send test emails from FreeNAS!!!! System->Settings->Email) If you get warnings that your hard drives are too hot do take action to cool them.

SMART testing:

Long Self Test - All disks, Long Self-Test, Each selected hour = 02, each selected day of month = 08 & 22, all months, all days of week

Short Self Test - All disks, Short Self-Test, Each selected hour = 01, every N day of month = 2, all months, all days of the week

This pretty much meets your requirements. Like I said, either use every single setting I use or do all the research and come up with your own. It's imperative to make sure tests never overlap while making sure they are frequent enough to be useful without being overly frequent or excessively wearing out your drives.
 
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#3
The situation is really complex so I recommend you either rigidly follow my schedule(recommended) or read up on all the stuff you should and shouldn't do and make up your own.
Thank you, I decided to follow your recommendation and copy your settings. Does this look all right to you?





Also set up smart monitoring & email the way you suggested, test email reached me without a problem. Is there anything else I should look into (besides upgrading from 2GB to 16GB and getting a UPS) ?

Thanks again for some solid help! :)
 

gpsguy

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#4
This is RAM I put in my N54L. Boots to 16Gb every time.

Kingston 16GB (2 x 8GB) 240-Pin DDR3 SDRAM DDR3 1333
ECC Unbuffered Server Memory Model KVR1333D3E9SK2/16G
 
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#5
Your settings look good to me. :)
 
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#7
Those settings recommended by cyberjock should cover all the drives. You must ensure you select all of them.
 

Wade

FreeNAS Experienced
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#8
ECCfrenaslover, nice avatar...

didnt realize you could select multiple drives at once by click hold dragging to select all, thanks
 
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#9
Glad you got it bro! Let's stay on topic eh? :D
 

Liriel

FreeNAS Aware
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#10
I have followed cyberJock's recommendations for my smart tests and email notifications.

I have three different pools and wasn't sure if it was better to run the scrubs simultaneously or stagger them. So far I have them staggered as follows:


Is there any reason why I shouldn't run them simultaneously? Would be nicer for managing reports if there is no downside to this approach.
 
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#11
I have 2 pools and they both scrub simultaneously.
 
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#12
Thanks for the test schedule!

My test emails work but I don't see anywhere that the S.M.A.R.T. test is going to email me if anything is wrong. Is this a settings I need to turn on or is it just common knowledge?
 

danb35

FreeNAS Wizard
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#13
The SMART email settings are separate, and part of the SMART service configuration. Make sure you've entered a valid email address there, and you should be good to go. If you want to test, set the "critical" temp threshold in the SMART configuration to something less than room temperature in celsius--you should get email notifications pretty quickly.
 
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#14
The SMART email settings are separate, and part of the SMART service configuration. Make sure you've entered a valid email address there, and you should be good to go. If you want to test, set the "critical" temp threshold in the SMART configuration to something less than room temperature in celsius--you should get email notifications pretty quickly.
Thanks it worked. This is the same email used by the S.M.A.R.T. tests?
 
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#18
This is an old thread but it is being referenced in newer threads. I have a couple questions, and a tip, that I think will be relevant to future readers.

1.) You say to run S.M.A.R.T. tests on *all* drives. My boot drives are a pair of mirrored consumer-grade USB Thumb Drives. I don't think they support S.M.A.R.T. testing. Any reason to include (or exclude) them from the S.M.A.R.T. tests?

2.) Scrubs for Pools are their own "Tasks", but Scrubs for the Boot Pool are listed under System / Boot Environments. You can set an interval (in days) but nothing else. I assume that setting this to 10 is recommended?

And now for the tip. For those running FreeNAS 11.2 or newer (with the new UI): You can define an interval of "Every 2 Days" by typing "*/2" into the "Days/*" field. See the screenshot below.
days.png


Thanks,
begleysm
 
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