1-bay NAS for 80 Mbyte/s?

[jan]

Hi all,

I need to save 48 jpg images of 1.6 Megabyte each per second.
That is 80 Mbyte/s.
By Gigabit Ethernet.

A single-bay NAS is preferred.
I am thinking of a SSD. We have good experience with Samsung series 840.

What is the bottleneck?
What NAS would you recommend?

Your general thoughts and ideas?
Suggestions and alternatives?

Thanks,
Jan

 

[stevech]

I'd not get a 1-bay NAS. Minimum of 2, so you can use two volumes for backup (I don't recommend RAID in a 2 bay). Synology and QNAP have 2 bay NASes (diskless) for well under $200. They have on-line demos at the web site. I am pleased with the 2 bay Synology I've had for some time.

If you buy a 1 bay, you'll have to have a like-sized USB3 or eSATA to use as backup, so the cost is a wash.

SSD in a NAS - I don't think they make sense for consumers. Too little storage for too little cost. And the Ethernet will become the bottleneck, leaving the SSD's speed untapped.

Unless you do a lot of GB file transfers, you won't see high speeds like 80MB/s. The limitation is the file system overhead, then the LAN speed, then the disk speeds on each end.

 

[jan]

Why do you think there is no 80 MB/s?
There are 48 files of about 1.6 Megabyte each, that is 80Megabyte/sec.
And it is continously. Each second. For hours.

When finished with recording the tray is pulled and shipped from the recording site to the office by courier.
Therefore a SSD is needed for robustness.

No backup is needed, we just do the recording itself, then at the office move the data to another system once. The the empty SSD is send back and re-used.

For easy operation I'd like a single SSD, not two. Also we do not need high capacity.
A single 120 GB SSD will do just fine.

Does one have to use both bays in a 2-bay NAS?
Or can we just use one?

It seems a NAS needs to have 2 bays to also have a powerfull enough processor that can handle 80 MB/s?

 

[L&LD]

If you're continuously writing ~80MB/s you'd be filling that drive in less than half an hour.

48*1.6*60*60=276,480 MB per hour or ~270GB.

An SSD with 120GB nominal capacity is closer to a formatted capacity of ~111GB.


111*1024/48/1.6/60=less than 25 minutes of recording per drive.


And even with an SSD inside, I don't think an entry level NAS would be able to guarantee this kind of write performance, day in, day out.


You'd need one of the more robust solutions and yes; you would not need to fill all drive bays up to get any use out of it.

Also keep in mind that being this close to the top end of the GB LAN limits - you will need a wired connection (cameras, NAS, etc.) to achieve this consistently.

 

[jan]

The Samsung series 840 EVO SSDs are available in 120, 250 and 500 GB size.

Of course it's all wired.

Any suggestions for a particular NAS from personal experience?

Any way to have a 2-bay set up in a way that it automatically fills one SSD after the other?

 

[stevech]

The Samsung series 840 EVO SSDs are available in 120, 250 and 500 GB size.

Of course it's all wired.

Any suggestions for a particular NAS from personal experience?

Any way to have a 2-bay set up in a way that it automatically fills one SSD after the other?

My recommendation is Synology. They have a few different 2 bay products. QNAP is commonly thought of as nearly equivalent but the admin software is not as polished as is Synology's. Look at those vendors' web pages.

I have several Samsung 840's, 120GB. Barely affordable. Used as the boot drive in PCs. Too small for use in a NAS. And in practical use, the speed of 7200 RPM disks can't be sustained in NAS transfers across a gigE LAN, except when doing huge files. Sending lots of smallish files increases the overhead. E.g., create files per second, in SMB on a LAN and with OS overhead, is 50 or so creates / sec. Overhead is compute times in the file system plus more head movement/latency. A 500GB SSD is $300 or more, vs. $80 for a 1TB 7200 RPM hard disk.

You'll see 20-30MB/s PC to/from NAS, sometimes faster with best case situations. When copying folders with lots of small files, you'll see 5MB/s average.

I suggest you think through your 3-2-1 backup strategy before buying hardware.

 

[TonyH]

Hi,
That is a catch 22 situation. Small NAS generally are not performance monster. You may need minimum 2 bay one to start looking at. I have
Synology DS713+ which is pretty decent performer. Look for one with dual cpu, good amount of memory.

 

[L&LD]

The Samsung series 840 EVO SSDs are available in 120, 250 and 500 GB size.

Of course it's all wired.

Any suggestions for a particular NAS from personal experience?

Any way to have a 2-bay set up in a way that it automatically fills one SSD after the other?

I realize you can get bigger SSD's (even 1TB EVO) - they won't help though if they need to be exchanged from more than 48 times a day to just under 7 times a day depending on the capacity of the drive used.


I don't know of any NAS units that fill one drive than another (except via JBOD - not recommended) properly.

Of course, a script has probably been written that will do just that (I have no experience in that though).


I am most familiar with QNAP 4 bay (RAID5) setups. Fully populated.

With a wired connection; I can see up to 115MB/s to those 3TB WD RED drives.


Hope you find a solution that works for your needs.