nMP, External Storage and Backup (NAS? RAID?)

[wheelhot]

Hello,
I have a question and would like to see what you guys think about it.

With my arriving-in-February 256GB SSD nMP, I already have my data on 4 external drive (3D CAD, Photo, Video, Music) and I'm now looking for a backup solution. All my external drive is Seagate FreeAgent GoFlex and I already own the GoFlex Thunderbolt adapter which I'll be using with the nMP.

Now for backing up, I'm planning to buy a 4 drive bay NAS. The thing I'm wondering is, am I able to use each of the NAS drive bay to backup each of the hard drive (3D CAD, Photo, Video, Music)? And what do they call this? Raid 1? Raid 5?

Oh and will they be any compatibility issues as I'm planning to get a USB 3 NAS (Thunderbolt NAS is too expensive) while my 4 external drives is connected to the nMP with Thunderbolt and the fact that not all 4 drives will be connected at once.

I guess depending on the NAS I buy, can I do manual backup? Cause not all my 4 external drive will be connected at once.

Thanks

 

[DJenkins]

The thing I'm wondering is, am I able to use each of the NAS drive bay to backup each of the hard drive (3D CAD, Photo, Video, Music)? And what do they call this? Raid 1? Raid 5?

You will need to manually back-up each drive individually to achieve what you want.
This is not a raid function, which typically merged drives together for either speed, redundancy or both depending on RAID level.

I think you may also need to know the difference between NAS (network attached storage) and DAS (direct attached storage).

NAS will connect via ethernet and will appear as a network device to OSX. They are self managed or managed by a web interface so I don't think they actually show up as a connected HDD in disk utility. A NAS is ideal if you have multiple users sharing data over a network.

DAS units (could be USB2, USB3, thunderbolt, Firewire800, mini-SAS etc.) will appear as a regular external HDD and can be configured directly using OSX disk utility. I think this is the sort of unit you should be looking at.

Your external device will likely come formatted in JBOD, which will show all 4 disks appearing as one large volume. It sound like you want to remove this formatting and return each disk to function on its own. This will depend on what sort of device you buy. Some NAS devices have their own web style internface but you may find functionality limited. I think if you get a standard external array and connect by USB3 you can do what you want using OSX Disk Utility. You will need to remove the JBOD group and reformat/partition each drive individually.

The you will need some software like Carbon Copy Cloner to manage your backups and scheduling. I have found CCC to be fantastic software.

Oh and will they be any compatibility issues as I'm planning to get a USB 3 NAS (Thunderbolt NAS is too expensive) while my 4 external drives is connected to the nMP with Thunderbolt and the fact that not all 4 drives will be connected at once.

I guess depending on the NAS I buy, can I do manual backup? Cause not all my 4 external drive will be connected at once.

There will be no compatibility issues here between thunderbolt and USB devices but if you really want everything backed up 1:1 across separate drives you will need to perform your backups manually.

This isn't so bad really - you can set up CCC to remember your tasks so you just open it up, choose your task and let it run. E.g. Clone "MOVIES" to MOVIES_BACKUP" and "PHOTOS" to "PHOTOS_BACKUP" as separate tasks.

It will only backup the files modified since last backup, leaving the files that haven't changed. This makes each incremental backup quite fast.

These tasks can be scheduled to complete at a predetermined time of day/week but in your case it will throw up a warning screen if your drives aren't attached.

There is other software out there, like chronosync but I've got the most experience with CCC and it's quite cheap too. I wouldn't recommend using time machine for these backups as it takes up a lot of data keeping temporary archives of your files whether you want it too or not. It's great for your main OSX drive but not so much for large data backups.

Hope this helps

 

[wheelhot]

NAS will connect via ethernet and will appear as a network device to OSX. They are self managed or managed by a web interface so I don't think they actually show up as a connected HDD in disk utility. A NAS is ideal if you have multiple users sharing data over a network.

DAS units (could be USB2, USB3, thunderbolt, Firewire800, mini-SAS etc.) will appear as a regular external HDD and can be configured directly using OSX disk utility. I think this is the sort of unit you should be looking at.

Aaah, the clears up some things. Hmm, so far Drobo, Synology and WD only offers NAS, any idea who manufactures a DAS? And since you mentioned NAS is connected via ethernet, why do manufactures like I mentioned above offers NAS with Thunderbolt and various connectors?

The reason why I thought NAS would be my solution cause I thought I could have my backup hard disks all kept in a single enclosure with only 1 USB cable coming out from it, rather then having 4 USB cables to be connected to my computer. For backing up, I don't mind the slower speed of USB 3 compared to Thunderbolt.

The you will need some software like Carbon Copy Cloner to manage your backups and scheduling. I have found CCC to be fantastic software.

I've used CCC before but never thought of using it like you said. Does it backups NTFS hard disks as well? Or I'll need to use a Windows equivalent software to do that? Cause only my 3D CAD HDD is partitioned to NTFS, the rest (Photo, Video, Music) is partitioned to MacOS Journaled.

This isn't so bad really - you can set up CCC to remember your tasks so you just open it up, choose your task and let it run. E.g. Clone "MOVIES" to MOVIES_BACKUP" and "PHOTOS" to "PHOTOS_BACKUP" as separate tasks.

It will only backup the files modified since last backup, leaving the files that haven't changed. This makes each incremental backup quite fast.

These tasks can be scheduled to complete at a predetermined time of day/week but in your case it will throw up a warning screen if your drives aren't attached.

Oh, that'll be neat especially it'll only backup files that has changed, I didn't know CCC has that feature (I only use it to clone the whole drive), does this feature work for NTFS-formatted HDD as well?

There is other software out there, like chronosync but I've got the most experience with CCC and it's quite cheap too. I wouldn't recommend using time machine for these backups as it takes up a lot of data keeping temporary archives of your files whether you want it too or not. It's great for your main OSX drive but not so much for large data backups.

Thanks for the advice! Cause I thought of using TimeMachine

Oh and thanks for taking your time to reply my questions! I'm a backup noob

 

[bcuzawd]

Aaah, the clears up some things. Hmm, so far Drobo, Synology and WD only offers NAS, any idea who manufactures a DAS? And since you mentioned NAS is connected via ethernet, why do manufactures like I mentioned above offers NAS with Thunderbolt and various connectors?

The reason why I thought NAS would be my solution cause I thought I could have my backup hard disks all kept in a single enclosure with only 1 USB cable coming out from it, rather then having 4 USB cables to be connected to my computer. For backing up, I don't mind the slower speed of USB 3 compared to Thunderbolt.

Drobo has the 5D, which is DAS.

I think you're just getting confused about the connection or something. The USB and TB connections are DAS (Direct Attached Storage). Meaning: they are directly plugged into your computer in some way via a cable other than an ethernet cable.

You would only use 1 cable (TB1 or USB 3.0 in the 5D example) to connect the external array. I'm not sure if you can configure the Drobo the way you are wanting to though.

The NAS (Network Attached Storage) uses the ethernet cable.

 

[wheelhot]

Drobo has the 5D, which is DAS.

I think you're just getting confused about the connection or something. The USB and TB connections are DAS (Direct Attached Storage). Meaning: they are directly plugged into your computer in some way via a cable other than an ethernet cable.

You would only use 1 cable (TB1 or USB 3.0 in the 5D example) to connect the external array. I'm not sure if you can configure the Drobo the way you are wanting to though.

The NAS (Network Attached Storage) uses the ethernet cable.

Aah, ok so NAS connects via Ethernet while DAS connects with regular ports. So is it possible for DAS to have NAS features as well or vice versa?

Product description regarding the Synology DS214

Designed with both safety and convenience in mind, DS214 contains the brand new tool-less hard drive trays, allowing users to fixate 3.5” hard drives without a screwdriver. Meanwhile, DS214 also supports hot-swappable hard drive trays, enabling instant and risk-free hard disk replacement. External storage access is made fast and easy, with two SuperSpeed USB 3.0 interfaces in the back, alongside one USB 2.0 interface in the front panel for quick access.

 

[ozbimmer]

What sort of NAS features u are looking for? RAID? I understand DAS functions are rather limited.

 

[VirtualRain]

Aah, ok so NAS connects via Ethernet while DAS connects with regular ports. So is it possible for DAS to have NAS features as well or vice versa?

Product description regarding the Synology DS214

Generally, a NAS enclosure can't work as a DAS enclosure and vice-versa. However in terms of RAID features, they obviously both can support a variety of RAID levels from 0, 1, 5, 10, etc. NAS usually offers other features like access via the internet (when you're away from home or off the network) and even media streaming/server functions. DAS is typically a dumb box of disks with RAID at most... no other features.

NAS is generally great when 100MB/s is sufficient... backups, archives, media collections and when multiple computers need access to this data or you want access to your data when off the network (eg. via the cloud).

DAS (with Thunderbolt or USB3) is preferable when speed is more important and the data is primarily only consumed by the computer to which it's attached since this data is only reachable when the DAS computer is up and running.

I use both. My Mac Mini has DAS which I use as a NAS, and my nMP has DAS of it's own.

 

[djarum69]

Aah, ok so NAS connects via Ethernet while DAS connects with regular ports. So is it possible for DAS to have NAS features as well or vice versa?

Product description regarding the Synology DS214

I have the Synology 414, and the USB ports it has are to attach USB devices to the NAS, not to attach the NAS to your computer. I have a couple of USB drives hung on mine that do local backups of my household shared directory. You could hang drives that you want to share on your LAN there, or install a printer to make it network accessible. They also use it for their WiFi and BlueTooth dongles. The Synology management software is proving to be super cool.

I do wonder why you want to have physical hard-drives in a box that mimic the ones you have on your computer. It would be easier and more economical to put a few really big drives in the NAS and make shared folders to mimic the disks. That way you could buy a 2 bay NAS like the 214 and a couple of 4 Gig drives that could back up everything… and then some.

 

[Sinx2oic]

Generally, a NAS enclosure can't work as a DAS enclosure and vice-versa. However in terms of RAID features, they obviously both can support a variety of RAID levels from 0, 1, 5, 10, etc. NAS usually offers other features like access via the internet (when you're away from home or off the network) and even media streaming/server functions. DAS is typically a dumb box of disks with RAID at most... no other features.

NAS is generally great when 100MB/s is sufficient... backups, archives, media collections and when multiple computers need access to this data or you want access to your data when off the network (eg. via the cloud).

DAS (with Thunderbolt or USB3) is preferable when speed is more important and the data is primarily only consumed by the computer to which it's attached since this data is only reachable when the DAS computer is up and running.

I use both. My Mac Mini has DAS which I use as a NAS, and my nMP has DAS of it's own.

I have always wondered about this. Why can't a NAS connect straight to your mac and also to your modem. This way you would benefit from speed of thunderbolt when working at home but also be able to pick up your files from anywhere you go using the NAS side of it. Sorry if this is a stupid question.

 

[Wuiffi]

I have always wondered about this. Why can't a NAS connect straight to your mac and also to your modem. This way you would benefit from speed of thunderbolt when working at home but also be able to pick up your files from anywhere you go using the NAS side of it. Sorry if this is a stupid question.

isn't gigabit ethernet way faster than the SATA HDDs (even in RAID) in most NAS ?- so as long as there is no SSD raid in the NAS I don't think there is much of a performance difference. (I could be totally wrong too ^^)

 

[theSeb]

isn't gigabit ethernet way faster than the SATA HDDs (even in RAID) in most NAS ?- so as long as there is no SSD raid in the NAS I don't think there is much of a performance difference. (I could be totally wrong too ^^)

No, that is not correct. Gigabit ethernet is basically a maximum of around 100 MB/s. A single 7200 RPM hard drive is capable of reading/writing faster than that.

 

[Gav Mack]

The Drobo 5D users can stick a 60Gb mSATA accelerator card inside their boxes to speed up transfers. A client has stuck one in his box and is pleased with the big boost in file copying to the 5D which is fully stocked with 4tb WD Reds. Not been back to see it working in the flesh yet though!

 

[shaunp]

isn't gigabit ethernet way faster than the SATA HDDs (even in RAID) in most NAS ?- so as long as there is no SSD raid in the NAS I don't think there is much of a performance difference. (I could be totally wrong too ^^)

With Gigabit Ethernet it in theory does 1000 Mb/s (1Gb/s). That's Megabits, not Megabytes. Roughly divide it by 10 and you get the throughput in megabytes per second.

SATA these days is either 3 or 6 Gb/s. SATA is much quicker than ethernet. If you connect a Thunderbolt array there is 10 or 20Gb/s depending upon the version you use. A typical HDD can sustain around 100-150MB/s, so you'd need a few of them to saturate a thunderbolt connection, but a single disk can easily saturate 1Gb/s ethernet with sequential workloads.

 

[Wuiffi]

No, that is not correct. Gigabit ethernet is basically a maximum of around 100 MB/s. A single 7200 RPM hard drive is capable of reading/writing faster than that.

With Gigabit Ethernet it in theory does 1000 Mb/s (1Gb/s). That's Megabits, not Megabytes. Roughly divide it by 10 and you get the throughput in megabytes per second.

SATA these days is either 3 or 6 Gb/s. SATA is much quicker than ethernet. If you connect a Thunderbolt array there is 10 or 20Gb/s depending upon the version you use. A typical HDD can sustain around 100-150MB/s, so you'd need a few of them to saturate a thunderbolt connection, but a single disk can easily saturate 1Gb/s ethernet with sequential workloads.

you both are absolutely right. Somehow I was thinking about the thunderbolt (2) speeds while talking about Gbit/s E. I need a beer ^^

 

[Sinx2oic]

So why can't we have both? A DAS that is also a NAS? getting the max speed at home from the hard drives and still being able to access files at a slower speed on the move

I'm guessing there is a reason for this, If anyone could explain I would appreciate it.

 

[echoout]

I have 2 really nice QNAP NASeseses. One thing I do which isn't EXACTLY what you're talking about is use a mobile USB 3.0 drive when I'm out and about that I then plug into my NAS when I get home. Then, all my Mac and PCs can access it via 10GbE and it gets backed up at the same time.

Just a thought and another possibility...

 

[djarum69]

I have 2 really nice QNAP NASeseses. One thing I do which isn't EXACTLY what you're talking about is use a mobile USB 3.0 drive when I'm out and about that I then plug into my NAS when I get home. Then, all my Mac and PCs can access it via 10GbE and it gets backed up at the same time.

Just a thought and another possibility...

I believe that you could do this with a Synology NAS. USB 3 drives can be added and exposed to the network as a shared drive, and you can use the local backup features to back the contents up internally as often as you would like. I've done both independently, but not in combination.

 

[echoout]

I believe that you could do this with a Synology NAS. USB 3 drives can be added and exposed to the network as a shared drive, and you can use the local backup features to back the contents up internally as often as you would like. I've done both independently, but not in combination.

Yeah, I wasn't saying it was QNAP specific, just another possibility.

 

[danny_w]

With Gigabit Ethernet it in theory does 1000 Mb/s (1Gb/s). That's Megabits, not Megabytes. Roughly divide it by 10 and you get the throughput in megabytes per second.

SATA these days is either 3 or 6 Gb/s. SATA is much quicker than ethernet. If you connect a Thunderbolt array there is 10 or 20Gb/s depending upon the version you use. A typical HDD can sustain around 100-150MB/s, so you'd need a few of them to saturate a thunderbolt connection, but a single disk can easily saturate 1Gb/s ethernet with sequential workloads.

While true that SATA (and even USB3) is much faster than GigE, most home NAS devices don't get even close to GigE speed. The slow processors in these boxes are a major limiting factor.

 

[FireWire2]

While Drobo give you ability to use different drives but it's a proprietary raid. it is a night mare to recover data, while conventional RAID you can drop in Linux and recover that
http://community.spiceworks.com/topic/208362-drobo-nightmare

You can use driver less raid like this for DAS:
http://www.newegg.com/Product/Product.aspx?Item=N82E16816119031
or
http://www.newegg.com/Product/Product.aspx?Item=9SIA0ZX0YB1379

 

[mikepj]

So why can't we have both? A DAS that is also a NAS? getting the max speed at home from the hard drives and still being able to access files at a slower speed on the move

I'm guessing there is a reason for this, If anyone could explain I would appreciate it.

It's not impossible, but it is a difficult problem to solve. A DAS has electronics in it to convert SATA hard drive instructions and data to travel over a bus like USB or Thunderbolt. The computer that you connect a DAS to is what controls how the bits are written to the drive (the file system, and lower level stuff like the partition table, etc).

A NAS is different. NAS devices usually are whole embedded computers in a hard drive box (most run some form of Linux). So the embedded Linux computer is controlling the filesystem, etc. In order for the NAS to act as a DAS, it somehow has to transfer control of the internal disks to another computer. This would require both computers (the client and the internal NAS computer) to support the same partitioning, file systems, etc.

That would just be the software side of things. Then you would need the hardware to correctly handle the transfer. Many NAS devices have USB ports, so you might think it shouldn't be a problem to plug it in to another computer. The problem is that the USB ports on the NAS are set to be masters on the USB chain, and that would conflict with your Mac wanting to be the bus master. The NAS hardware would have to somehow set the port to be a slave device, and then correctly handle instructions being passed to it over that port.

There are just a lot of details that would have to be dealt with before you could have a NAS/DAS combo, and in a lot of cases (like if the filesystem support doesn't match up), it wouldn't work at all.

That's why you don't see combo NAS/DAS devices.

 

[wheelhot]

What sort of NAS features u are looking for? RAID? I understand DAS functions are rather limited.

Well I now know that I'm not looking for NAS and instead looking for a DAS.

Mainly cause I'm looking for a solution to backup my 3D CAD, Photos, Videos and Music hard disks, they are currently located in separate portable drives.

I might consider to consolidate Photos, Videos and Music into 1 hard drive and do a RAID backup with it.

The thing that bugs me the most regarding DAS like Drobo or Synology is, what happens when my hard disk becomes full? Cause Video take loads amount of space and if I swap it with a larger capacity hard drive, what happen to my files in that hard disk? And what happens when I max out, let say 8TB of space (4 bay DAS), and a single HDD max capacity at that time is 2TB?

----------

While Drobo give you ability to use different drives but it's a proprietary raid. it is a night mare to recover data, while conventional RAID you can drop in Linux and recover that
http://community.spiceworks.com/topic/208362-drobo-nightmare

You can use driver less raid like this for DAS:
http://www.newegg.com/Product/Product.aspx?Item=N82E16816119031
or
http://www.newegg.com/Product/Product.aspx?Item=9SIA0ZX0YB1379

Aah, so the horror story about file recovery with Drobo prevails. I thought after so many years they would've ironed out the problems.

Hmm, the Lacie DAS solution is surprisingly cheaper then I thought, could it be that you have to buy your own 2TB drives?

----------

And wow, I learn many new things about bandwidth, NAS, DAS and etc! Thanks guys!

 

[Sinx2oic]

It's not impossible, but it is a difficult problem to solve. A DAS has electronics in it to convert SATA hard drive instructions and data to travel over a bus like USB or Thunderbolt. The computer that you connect a DAS to is what controls how the bits are written to the drive (the file system, and lower level stuff like the partition table, etc).

A NAS is different. NAS devices usually are whole embedded computers in a hard drive box (most run some form of Linux). So the embedded Linux computer is controlling the filesystem, etc. In order for the NAS to act as a DAS, it somehow has to transfer control of the internal disks to another computer. This would require both computers (the client and the internal NAS computer) to support the same partitioning, file systems, etc.

That would just be the software side of things. Then you would need the hardware to correctly handle the transfer. Many NAS devices have USB ports, so you might think it shouldn't be a problem to plug it in to another computer. The problem is that the USB ports on the NAS are set to be masters on the USB chain, and that would conflict with your Mac wanting to be the bus master. The NAS hardware would have to somehow set the port to be a slave device, and then correctly handle instructions being passed to it over that port.

There are just a lot of details that would have to be dealt with before you could have a NAS/DAS combo, and in a lot of cases (like if the filesystem support doesn't match up), it wouldn't work at all.

That's why you don't see combo NAS/DAS devices.

Thanks for clearing that up a bit. When my nMP comes I am considering getting:
DAS: 12TB http://www.caldigit.com/T3/ for my main work
NAS: 6TB Synology DS214play mostly for films/photos/plugins
Thanks for the help

 

[phrehdd]

Just some thoughts here...

If you are looking for back up - do DAS. There are lots of options out there from simple Western Digital (or Seagate) back up devices to more involved DAS that includes ability for RAID.

DAS RAID - this comes in two flavours: a box with multiple drives that has built in hardware/firmware to create and handle RAID and then there are simple multi-drive enclosures where you opt to create RAID 1 or 0 or O+1 or 1+0 via your Mac.

NAS is an entirely different beast and any NAS with 3 or more drives often will offer items such as RAID 5. I would not consider NAS that is with RAID as the best back up and some would simply say it is not a real back up solution.

My guess is you would be best off to go DAS and if you are insistent on RAID then simply go for mirrored drives controlled by your MAC rather than external device hardware/firmware. I say this because your are more likely to have success fixing things if they were to go wrong when the only controller is your Mac. (Please be aware OSX is not perfect and you may opt for a software solution that is installed on your Mac). In my opinion, I would use single drives for back ups. You can always rotate drives and update the deltas only (make one full backup, and the deltas are only the difference between your Mac and back up - both added files and removal of deleted if you choose).

FYI - I use two NAS units and also external drives for my system. The externals are for backups and also for mobile use and they are OSX formatted. This has worked well for me for many years.

 

[Cubemmal]

I got the Promise diskless 4 bay which is wonderful.