NAS disk setup questions

[MikeFromMesa]

I plan to buy an NAS enclosure for use with Time Machine. I don't have a lot of experience with this kind of setup but what I do have is some experience with an NAS drive that I use for regular storage and that setup allowed me to specify that the disk would shut down after x minutes of non-access or stay spinning all the time. On my Mac that seems to mean that I have to eject the disk and then, after the specified time period (10 minutes in this case) the disk spins down. It I leave it mounted it continues to spin continuously even if I am not accessing it. I don't know if that is normal or, perhaps, a product of the inexpensive enclosure I bought.

Because of that I have several questions about setting up a good quality NAS (perhaps Synology) enclosure for Time Machine. Can I set up a spin down time for a disk being used for Time Machine? Will Time Machine wake up such a disk on its own? Or will the attempt fail? Do users normally set up a spin down time for a home NAS system? Is my experience of having to manually eject an NAS device normal for a Mac? Or is it a byproduct of a $45 enclosure? And anything else that might help me in making the right purchase decision. This machine would probably only be serving a single Mac (a Mini).

Thank you for any help you can provide.

 

[Ember1205]

NAS is Network-Attached Storage, so "ejecting" a disk from the MAC has a slightly different meaning than if it were physically connected. Not sure if you're thinking of "eject" in the physical connection way or if you really mean unmounting a network share on a remote drive.

The NAS appliance would be where you would need to look for settings and controls that manage the actual physical disk and you would set parameters in there to allow the disk to spin down if it wasn't being accessed in a certain amount of time.

 

[MikeFromMesa]

NAS is Network-Attached Storage, so "ejecting" a disk from the MAC has a slightly different meaning than if it were physically connected. Not sure if you're thinking of "eject" in the physical connection way or if you really mean unmounting a network share on a remote drive.

The latter.

I currently have a very inexpensive (and so functionally limited) NAS drive attached on my system. The device only understands drives formatted as exFAT and, regardless of settings, will not spin down unless the device is ejected (i.e., unmounted) using Finder. That means that although I have it set to spin down after 10 minutes it will run continually once it is mounted until I manually "eject" it and then, 10 minutes later, it will stop spinning.

It is annoying in that I should not have to manually do something like that but, as I said, it is a very inexpensive NAS enclosure with my own disk mounted inside. The configuration is done through the web interface and it only has 3 options - spin continuously, stop after 10 minutes of non-use and stop after 20 minutes of non-use. That was the reason for my questions. I have ordered a new dual bay enclosure (by a more well known manufacturer) and wanted to know if my experience with my current NAS was representative of all such devices or not.

The NAS appliance would be where you would need to look for settings and controls that manage the actual physical disk and you would set parameters in there to allow the disk to spin down if it wasn't being accessed in a certain amount of time.

One would think so. However, as I mentioned, my present device will not spin down as long as it is mounted and that was the reason for my questions. I have to assume that more mainstream devices will function properly but I wanted to ask before I invested any "real money" in a device.

 

[Ember1205]

Maybe don't go the route of a NAS appliance, then?

I can't see the value in buying a NAS device - I use a no-longer-used PC, load it with Linux, attach whatever drives I want, then set all of the parameters and variables. My current "NAS" has 14TB of storage in it across four drives and is nothing more than a PC that I loaded Linux onto. I set it up as a SAMBA server and can access any file from any device (with the right client on mobile devices) this way so long as I have the correct user credentials. I've been doing it this way for well over a decade.

 

[MikeFromMesa]

I suppose that works if you have the space and the outlets for all of that. I have neither, nor do I trust my old laptop to work properly if I tried to set it up like you have done, nor do I have the external drives you talked about.

The cost of an NAS device with 2 drives is about $200 for me while the cost of hanging external usb drives off of a PC is probably about $250. I can set up the NAS as a RAID device but there is nothing native on a Linux laptop that I am aware of that will take care of mirroring unless I buy the software to keep the 2 disks in sync. For me I don't think your suggestion will work as easily as an NAS but it seems like an interesting alternative.

 

[Ember1205]

Linux includes RAID software in the OS which is almost certainly what the "NAS Appliance" is using (you aren't getting a device with a hardware controller and two drives for $200).

When I mentioned using a PC with Linux, I was specifically suggesting that you use -internal- drives (not sure if you might have thought I was saying to use USB-connected drives). And, since it's Network-Attached, it needs only be able to connect to your network in order for your devices to access it. My servers are all in the basement which is also where my switch is that creates my home network.

An unused PC costs you nothing. Linux costs you nothing. You spend money only on the drives that suit your needs. If you happen to have a couple of drives sitting around that each at least the size of space you require (because you would mirror them and only get the effective space of one), then you don't even need to buy drives. I recently bought a pair of 5TB drives for around $300, so you can certainly acquire a fair amount of disk space without spending gobs of money.

I will tell you that I also looked into FreeNAS as an alternative to simply building my own Linux server and, IMHO, it's way over-complicated and way over-powered for home use. Anything that uses that software internally will ALSO be over-complicated. So, be sure you know what you're buying with a NAS device if you still go that route.

 

[MikeFromMesa]

> you aren't getting a device with a hardware controller and two drives for $200

Actually I am getting a dual drive NAS device that is diskless and that cost me about $160. I also bought a 2TB bare bones drive that cost me another $70 and had a second 2TB drive so the total cost was about $230.

> not sure if you might have thought I was saying to use USB-connected drives

That is exactly what I thought you were saying.

> An unused PC costs you nothing

Unless you don't already have one, and then it closes quite a bit.

 

[Ember1205]

> you aren't getting a device with a hardware controller and two drives for $200

Actually I am getting a dual drive NAS device that is diskless and that cost me about $160. I also bought a 2TB bare bones drive that cost me another $70 and had a second 2TB drive so the total cost was about $230.

Not bad in terms of total cost - but I'm still betting it doesn't have a hardware RAID controller. The easy way to differentiate is this: If you have to configure the drives and the RAID status as the device boots, it's hardware (or pseudo-hardware). If you configure drive striping / mirroring through a command line or GUI -after- booting, it's software.

> not sure if you might have thought I was saying to use USB-connected drives

That is exactly what I thought you were saying.

> An unused PC costs you nothing

Unless you don't already have one.

Many people have old PC's around that they've moved off of (to a newer one) or just don't use for whatever reason. Not everyone has one, and it seems you are in this group. You can often pick up a used one off of CraigsList or FreeCycle for free with no drives and possibly little or no RAM. Since all you're doing is controlling disk access, CPU quantity and speed isn't important - you need a high speed network connection (to match your network - no point in having a GIG interface if your home network only supports 100Mb), disk space, and some RAM to keep performance decent.

Sounds like you've got a plan, though, and it should work out to suit your needs.

 

[MikeFromMesa]

Not bad in terms of total cost - but I'm still betting it doesn't have a hardware RAID controller. The easy way to differentiate is this: If you have to configure the drives and the RAID status as the device boots, it's hardware (or pseudo-hardware). If you configure drive striping / mirroring through a command line or GUI -after- booting, it's software.

I don't know as the device (a Western Digital 2 bay diskless NAS - Series EX2 Ultra) has not yet arrived. This device, along with the Synology and QNAP NAP devices, were the ones I was considering. They are all RAID compatible but I can not say if that is hardware or software.

As for network speed, my current router is ac compatible and although I would like faster wireless speed than I have I do not believe that is currently available. In any case Wireless ac should be fast enough for Time Machine backups as well as network storage and, perhaps, streaming support. I will know more when the device arrives and I have it set up.

 

[Ember1205]

When considering network speed for a NAS device, you have to look at the wired speed, not the wireless. NAS devices require a physical connection.

 

[MikeFromMesa]

When considering network speed for a NAS device, you have to look at the wired speed, not the wireless. NAS devices require a physical connection.

The NAS device requires an ethernet connection. That connection is surely faster than the wireless speed, regardless. Wireless AC has a theoretical speed of 1.3Gb/sec while the theoretical top speed of ethernet is 10Gb/sec. Both of these are theoretical but it seems fairly clear that ethernet is much faster than Wireless AC and would remain so in the "real world".

The final speed to the device is, of course, dependent upon the slowest connection, but that seems like it must be the Wireless AC so I am not sure why you are talking about the ethernet part of the connection. Or are you referring to something else?

 

[Ember1205]

There's not much point being concerned with your wireless speeds for a NAS device. You have to look at the physical network connectivity because that's how the NAS device connects. Go with the highest speed your physical connections will support. I previously had a gigabit switch and a router with 100Mb ports. So, even though my main switched network would support gigabit, any wireless devices would only be able to connect through the router which capped out at 100Mb. Still, I looked to the gigabit switch as the piece that would govern what kind of connection I should run in my NAS / Server.

 

[MikeFromMesa]

There's not much point being concerned with your wireless speeds for a NAS device. You have to look at the physical network connectivity because that's how the NAS device connects. Go with the highest speed your physical connections will support. I previously had a gigabit switch and a router with 100Mb ports. So, even though my main switched network would support gigabit, any wireless devices would only be able to connect through the router which capped out at 100Mb. Still, I looked to the gigabit switch as the piece that would govern what kind of connection I should run in my NAS / Server.

OK. So if I understand you correctly I need to think about the connection speed of the ethernet ports in the router. In my case the router is an Apple Airport Extreme (model A1521) and the Apple spec sheet lists the ethernet connections as Gigabit LAN ethernet ports. I assume from that that the wired part of the connection is in line with the Wireless AC speeds (in the real world). Is that what you were referring to?

I had already done a test to see what the transfer speeds actually were. I transmitted a folder of files at both the N and AC connections and found that the AC was about double the N speeds which, I believe, is in line with the theoretical speeds. Both, of course, were noticeably lower than the theoretical max speeds, but the AC was about twice the speed of the N.

 

[Ember1205]

The gigabit ports are going to be your "limiting factor" - the wireless piece doesn't matter. You have to be considerate of the fact that all that matters is whether or not the NAS device itself is connected with the best option available. Because it's Network-Attached, it's "available" to any device on the network with the right credentials and such to connect to it. So, make certain that it's using the best connection available for your network.

For example: I have a couple of servers that I was previously using that had 100Mb cards in them. Connecting them to a gigabit switch didn't help them in any way and made transfers to/from those servers significantly slower for those machine that were connected with gigabit. Since they were intended to serve connections from multiple clients at the same time, the 100Mb cards in the servers were bottlenecks causing performance degradation. I upgraded the cards to gigabit and saw much smoother access from all clients, even wireless ones - remember that data transfers to/from the NAS will be cumulative of all devices accessing the device at the same time. So, even having two machines each attempting to connect at 54mb (802.1g) would outstrip a 100Mb network interface.

 

[MikeFromMesa]

The gigabit ports are going to be your "limiting factor" - the wireless piece doesn't matter.

Well, yes but ...

I first must say that I am not an expert in this area and, although I am thoroughly familiar with network software in general, I am not a "hardware guy". Having said that ...

It is obvious that any data transfer is limited by the slowest connection. But a theoretical 1.3 Gb/sec transfer in the lab is probably much more like 600 or 700Mb in the "real world" and if that is true, then the Gb wired connection is not the limiting factor, the wireless part is. Unless I am wrong in my calculations, of course. then again perhaps Apple's Gb LAN connection really is not up to 1 Gb but slower. How much slower than wireless AC can it be?

 

[Ember1205]

Well, yes but ...

I first must say that I am not an expert in this area and, although I am thoroughly familiar with network software in general, I am not a "hardware guy". Having said that ...

It is obvious that any data transfer is limited by the slowest connection. But a theoretical 1.3 Gb/sec transfer in the lab is probably much more like 600 or 700Mb in the "real world" and if that is true, then the Gb wired connection is not the limiting factor, the wireless part is. Unless I am wrong in my calculations, of course. then again perhaps Apple's Gb LAN connection really is not up to 1 Gb but slower. How much slower than wireless AC can it be?

You're looking at this with a specific use case in mind. When designing a solution like this, you have to step back and think of other use cases and possible ways you would leverage it. Your specific use case is 1:1 between your Mac and the drive and only for backup. What happens if you end up with a second Mac? And they're trying to back up at the same time? It then becomes significantly more important to have connected the NAS device via the gigabit connector.

Actual data throughput is dependent on many factors and can't be accurately measured on anything except test streams of data. Real-world numbers will fluctuate all over the map because of packet size, total amount of data to be transmitted, contention in the switching fabric to handle ACK packets, sliding TCP windows due to any number of network factors, etc.

My point in my previous post was basically forget about the wireless piece. It doesn't matter. Implementing something today should take into account all of your needs today any "most" of your possible needs over the next couple of years. Anything less and it's going to end up being a throw-away solution when you outgrow (which may well be much sooner than you might have thought).

If you have Gig connections on your network, then that's how the NAS should be wired in.

 

[MikeFromMesa]

> It then becomes significantly more important to have connected the NAS device via the gigabit connector

I am starting to think that I have made a basic mistake in understanding the point you were making. I have been assuming that when you referred to a gigabit connector you were talking about a wire capable of carrying data at that speed, that is, an ethernet cable. I am now starting to think that you are referring to an actual appliance rather than just a cable and I guess I need to ask specifically what you mean by "gigabit connector". Perhaps then I will see the point you are making.

> What happens if you end up with a second Mac?

I actually had wondered how this would work if I was trying to back up 2 Macs using Time Machine. Can two Macs use a single NAS disk with Time Machine? I have no idea.

 

[Ember1205]

What are the specifications of the device? Does it support 1000baseT (gigabit)?

What are the specifications of your router? Does it support it?

If so, connect it and you're good to go. If the NAS device doesn't support it, look into options to upgrade the network interface card.

 

[MikeFromMesa]

What are the specifications of the device? Does it support 1000baseT (gigabit)?

What are the specifications of your router? Does it support it?

If so, connect it and you're good to go. If the NAS device doesn't support it, look into options to upgrade the network interface card.

From what I have been able to ferret out of the specs the router (Airport Extreme) ethernet connections are Gigabit rated as are the connections on the NAS bay. Presumably that means that the theoretical maximum throughput is 1Gb so perhaps I am OK with this purchase.

 

[Ember1205]

From what I have been able to ferret out of the specs the router (Airport Extreme) ethernet connections are Gigabit rated as are the connections on the NAS bay. Presumably that means that the theoretical maximum throughput is 1Gb so perhaps I am OK with this purchase.

I wouldn't get wrapped up in "theoretical maximums" on any of this stuff. By leveraging the highest connections available (gigabit), you're future-proofing yourself to the best of your ability. The rest is all controlled by the software that manages the data transmissions and there isn't anything you can do about that.