HDDs don't go to standby

[mik3]

Hi everybody. I'm new to NAS in general and FreeNAS. Built my own box with 3 HDDs each being 4TB.

I have watched the box for a few days now and even though I told FreeNAS to put my HDDs to standby as I'm not using the data very often, they are "always on".

Here are the current settings:

http://awesomescreenshot.com/0b442mcg96

Any ideas what I did wrong?

Thanks!
Mike

 

[Blues Guy]

Hi, everybody!

I do have the same problem, so I watched the system carefully and noticed a very short HDD-access (access-LED flashing once for a very short time) every 5 seconds with all the clients turned off. I'm sure, noone accessed the FreeNAS-system.

The only thing that came to my mind is that ARC does a reorganisation every 5 seconds. Could it be that the ARC writes small amounts of data back to the disks every few seconds?

My system is:
HP Z210, Intel Xeon E3-1270 (3,4GHz, 4C, HT), 16GB ECC-Ram, 4*2TB Samsung 7200rpm SATA-drives, single RAIDZ1-pool, latest 9.3-release.

Thanks everyone for your great support!

Bernhard

 

[danb35]

Could be the ARC, could be something in the system logs, could be one or more of the reporting databases, could be something with Samba. ZFS in general writes to the disks in bursts about five seconds apart. What you're seeing is pretty much normal. The only decent way to avoid it would be to create a separate pool on an SSD or two, and place the .system dataset (along with any jails) on that pool. Or you could just not worry about it, which is what I do.

 

[Blues Guy]

I tried shutting down all the jails, which didn't change anything. So, it must definitely be a system thing. Does this mean, there's no easy way to spin down the drives, when nobody is using the server, because the system is always writing something to the disks?

 

[Blues Guy]

By the way, the only thing that is in my debug.log every minute is:
-----------------------
Dec 22 20:51:02 jarvis autosnap.py: [tools.autosnap:58] Popen()ing: /sbin/zfs list -t snapshot -H
Dec 22 20:51:02 jarvis alert.py: [middleware.notifier:226] Popen()ing: /sbin/zpool status -x freenas-boot
Dec 22 20:51:02 jarvis alert.py: [middleware.notifier:226] Popen()ing: zpool list -H -o health brain
Dec 22 20:51:02 jarvis alert.py: [middleware.notifier:226] Popen()ing: /sbin/zpool status -x brain
Dec 22 20:51:02 jarvis alert.py: [middleware.notifier:226] Popen()ing: zpool list -H -o health brain
Dec 22 20:51:02 jarvis alert.py: [middleware.notifier:226] Popen()ing: zpool get -H -o value version brain
Dec 22 20:51:04 jarvis autorepl.py: [tools.autorepl:117] Autosnap replication started
Dec 22 20:51:04 jarvis autorepl.py: [tools.autorepl:118] temp log file: /tmp/repl-44531
Dec 22 20:51:04 jarvis autorepl.py: [tools.autorepl:445] Autosnap replication finished
-------------------------
Other than that, there's nothing in the debug.log

 

[danb35]

Pretty much.

 

[Blues Guy]

I tried shutting off all the jails and disabling all the services (exept smart), didn't change anything. is there a way to disable the reporting to check, if it's that?

The logs should be writtin in RAM and if I disable all the jails and services, except the reporting database, what could access my data pool?

 

[Blues Guy]

I just had a look at my (totally idle) server and I'm seeing 100kB/s data write at all times. Is this normal?

 

[mik3]

I have the described behavior after fresh install, no jails, no shares. Nobody accesses the NAS, still the discs are always on. This cannot be the wanted behavior of the FreeNAS system, otherwise the options don't make sense...

 

[danb35]

Yes, this is the expected behavior. Stuff is being written to, and read from, the .system dataset all the time. If you want your disks to spin down, the .system dataset needs to be somewhere else, like on an SSD. Yes, this means that 90+% of the time, the spin-down options will be irrelevant.

 

[Blues Guy]

Is it okay to put the .system dataset on a single SSD or is it important enough to be mirrored? How big does the SSD need to be?

 

[Glorious1]

I have a 120 GB SSD in a USB enclosure plugged into the back of my box. With System > System Dataset, I pointed everything to the volume/dataset I created on that SSD.

The other thing you have to do, not mentioned yet, is to set the SMART settings > Power Mode to Standby. Then SMART won't spin up the disks to check them. The check interval for SMART should probably be longer than your HDD Standby timer setting in the disk settings.. Then of course in the disk settings you need Advanced Power Management at 127 or lower. This worked for me, disks on the motherboard ports were able to spin down.

However, if you've got disks getting written to at 100 kB/s, you've got something else going on. If sharing is turned off, you must have a replication or rsync going on.

 

[SweetAndLow]

Keep in mind that spinning down your drives probably puts more wear and tear on your drives than keeping them running 24/7.

 

[Blues Guy]

@Glorious1 : Thank you for your pointers. Since I'll be upgrading the SSD in my desktop PC, I'll have a 120GB SSD ready and the FreeNAS-machine has an extra SATA3 port free. I can just try it. However, I can't use SMART Advanced Power Management below 128, otherwise, the drives are spinning down after a few seconds of inactivity and immediately spinning up again, because (as I've described), every 5 seconds, something is written to the disks.

@SweetAndLow : Yes, I've heard that, but I think, moving the heads every five seconds 24x7 isn't good for them either. I use 4 Samsung-drives (2TB, 7200rpm) and they've been in my Thecus-NAS-box for 3 1/2 years now without a problem. Nevertheless, I think, they might be near their end of life.

 

[Blues Guy]

@Glorious1 : Thank you for your pointers. Since I'll be upgrading the SSD in my desktop PC, I'll have a 120GB SSD ready and the FreeNAS-machine has an extra SATA3 port free. I can just try it. However, I can't use SMART Advanced Power Management below 128, otherwise, the drives are spinning down after a few seconds of inactivity and immediately spinning up again, because (as I've described), every 5 seconds, something is written to the disks.

I forgot about the replication-bit: I don't have replication or rsync configured, since I don't have a second machine to replicate data to or from. And it's about 300KB/s that is written (4 disc RAIDZ1, every disk writing 100KB/s minus parity).

 

[Ericloewe]

@Glorious1 : Thank you for your pointers. Since I'll be upgrading the SSD in my desktop PC, I'll have a 120GB SSD ready and the FreeNAS-machine has an extra SATA3 port free. I can just try it. However, I can't use SMART Advanced Power Management below 128, otherwise, the drives are spinning down after a few seconds of inactivity and immediately spinning up again, because (as I've described), every 5 seconds, something is written to the disks.

@SweetAndLow : Yes, I've heard that, but I think, moving the heads every five seconds 24x7 isn't good for them either. I use 4 Samsung-drives (2TB, 7200rpm) and they've been in my Thecus-NAS-box for 3 1/2 years now without a problem. Nevertheless, I think, they might be near their end of life.

Drives aren't limited by head movements, but they are limited by head parking cycles.

 

[mik3]

I'm aware of the lifspan issues, thanks for the explanation though. I'd rather have my NAS use 3W instead of 17 when I only need it an hour each day

 

[Glorious1]

So Blues Guy has something writing to his disks constantly. Obviously they're not going to sleep with that going on.

mik3, you may need to put your System Dataset to a separate volume to let the rest sleep. By the way, how do you know for certain your drives aren't sleeping?

 

[Glorious1]

Huh, I just noticed I've got similar continuous writing like Blues Guy. It's been going since I reconfigured my main pool and restored from backup two days ago.:

The good news is, it's on the System Dataset on the SSD, so it's not preventing my disks on the motherboard from spinning down. Wonder what all that is? There are no files being created.

 

[mik3]

I have an external power source that shows the Voltage and Current used at any give time. The system without HDDs draws around 4W and when the HDDs spin up it goes to around 18W. I have monitored this reading and it never drops below 18W. Also, you can hear the HDDs spinning since the case I use is still open