NAS and RAID

bastic

bastic

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I want to get a NAS..
Want to use it as a storage and backup...
what would be best setup for it ?
I know RAID5 would give best performance but would it be safe ?
I have 2x2TB drives I could use...when prices of HDD's go down, could get 2 more...

thanks
 
I have a Qnap 4 bay NAS with 2 hard drives set as raid 2 (I think - they mirror each other) It has done all it is meant to do for the last 18 months, I will be adding hard drives when needed but so far all I can say is that it has been problem free so comes recommended !
I run my Sonos music system off it and keep a back-up of all my photographs on it, and it just sits in the corner doing its job !
 
regarding safety no matter what raid level you use you should have a backup copy. no raid level is 100% safe.

you wont be able to do raid5 with 2 drives, 3 or more.

as for brands, i guess everyone has their preference. im in the synology boat. avoid netgear in my opinion.
 
stevewestern said:
I have a Qnap 4 bay NAS with 2 hard drives set as raid 2 (I think - they mirror each other) It has done all it is meant to do for the last 18 months, I will be adding hard drives when needed but so far all I can say is that it has been problem free so comes recommended !
I run my Sonos music system off it and keep a back-up of all my photographs on it, and it just sits in the corner doing its job !
Click to expand...

you mean raid1 for mirroring.
 
bastic said:
I want to get a NAS..
Want to use it as a storage and backup...
what would be best setup for it ?
I know RAID5 would give best performance but would it be safe ?
I have 2x2TB drives I could use...when prices of HDD's go down, could get 2 more...

thanks
Click to expand...
You'll need to define storage AND backup. It's pretty pointless to back something up to the same drive it is being stored on.

As Neil has said, RAID5 is 3+ disks. To be 100% safe even with RAID5, you will need a backup on a physically different medium.

If you want a RAID array, you should look at the specs carefully. I don't think you can generally add a disk to a RAID array (e.g. moving from a 3 disk RAID5 -> 4 disk RAID5 isn't just a case of "adding a disk").
 
arad85 said:
You'll need to define storage AND backup. It's pretty pointless to back something up to the same drive it is being stored on.

As Neil has said, RAID5 is 3+ disks. To be 100% safe even with RAID5, you will need a backup on a physically different medium.
Click to expand...

agreed. my raid5 is backed up to a separate raid device and photos off to blu-ray.

If you want a RAID array, you should look at the specs carefully. I don't think you can generally add a disk to a RAID array (e.g. moving from a 3 disk RAID5 -> 4 disk RAID5 isn't just a case of "adding a disk").
Click to expand...

normally you just have to slot the drive in, initialise it and extend the volume. but it will depend on the device.
 
I personally like RAID 1 with a hotspare. 2 disks are mirrored and if 1 fails, the hotspare replaces it automatically. So out of 3 disks, you can lose 2.

You waste a lot of space as you are using the 3 disks, but only have the space of 1 (RAID 5 uses 3 disks and gives you the space of 2, or 4 and the space of 3). RAID 1 is also generally easy to recover from in terms of disaster recovery, if if your NAS died, you would need another device that can access a RAID 5 array (and load in the foreign array) to access the data. With RAID1 each drive contains all of the data and so you can just use it in another machine.

In my experience most people are dropping the complexities of RAID 5 for either simpler RAID 1 or RAID 10.
 
NAS drives are great, but as already stated don't confuse backup with archiving.

Consideration should also be given to off-site backup of some description.

Belt, braces and a spare pair of trousers !
 
I still would use icy box with 1TB only for photos stored away :)
and RAID5 would be good for storage in general..
 
neil_g said:
not necessarily. depends on controller.

eg. i think it was someone on here that had a drobo in raid1 fail, that data was not accessible.
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Most of the time you can :)

EDIT :- Didn't know that about Drobo, some of the NAS boxes try to be too clever and don't do quite what you think they do.
 
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Its the complexities of the array and the performance hit with a degraded array and the performance hit during the rebuild.

If you want performance use RAID 10. If you just want security, RAID 1.

Microsoft recommend RAID 5 still, but people are moving away from it (it was recommended on the last MS course I was on to use RAID 10, but for the exam use RAID 5)
 
i see your point but for most companies shelf space and budget is usually the deciding factor ;)

rebuilt a couple TB RAID5 arrays with no major performance hit (over fibre).

but like i say horses for courses so no point bickering about it :D
 
The recommendations of using either raid 1 or raid 5 for performance are irrelevant if the NAS device itself is not upto the job.

And most "home" and entry-level style NAS devices can't max out a 3.5" drive (100mb/sec), so it does it matter?

;)

PS. Not to mention a users network and capacity/drive speeds on their host.
 
Zarch said:
The recommendations of using either raid 1 or raid 5 for performance are irrelevant if the NAS device itself is not upto the job.
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This is very true. I recently upgraded my filestore to run ZFS and a RAIDZ (RAID5 like configuration). The "server" is an AMD Athlon II x4 630 with 2Gbytes of memory and 4 disks in a 3+1 stripe. I was getting copy speeds fluctuating between zero and 70ish MBytes/sec. in a breathing pattern (burst, quiet, burst, quiet). With a bit of reading around, this is a memory starvation problem where you can't overlap writes to the disk with writes to memory. And I do a reasonable amount of large file copies as I recode all my media to put on my main filestore.

£40 on an extra 8GByte of memory solved it and I can now copy files from my 1Tb disk locally to the remote disk at 100+MBytes a sec (which is probably limited by the Gbit network). This is 3x my previous network copy speeds onto a single disk XP system where I was limited to ~35Bytes/sec. Fundamentally, networked disk performance is limited by the single slowest element in the chain.
 
agreed that low end NAS units can be horribly slow, my old netgear was aweful.

spend a bit more and get one with upgradable memory and at least 1 gigabit connection, preferably 2 which can be teamed.
 
arad85 said:
Fundamentally, networked disk performance is limited by the single slowest element in the chain.
Click to expand...

Exactly!

I have posted this NAS Basics guide before, which I did for AVForums. Hopefully people might find it useful: http://www.avforums.com/forums/netw...rotection-performance-configuration-more.html


neil_g said:
agreed that low end NAS units can be horribly slow, my old netgear was aweful.

spend a bit more and get one with upgradable memory and at least 1 gigabit connection, preferably 2 which can be teamed.
Click to expand...

Sadly Neil,

People look at bottom dollar and expect their cheap NAS to perform...... it won't.

Better to massage their expectations now, rather than after they've shelled out. :)
 
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love all the thechno d!ck waving ;)

for your data to be 'secure' it needs to exist seperately in 3 places. i.e. locally, on your archive and a backup.

think about your system of what is stored at each level such that its easier to only backup what you really need.

your nas (archive) will be limited by its throughput in terms of disks which is related to the type and how/if you use raid, but also the performance of the box theyre in and the network connection you have to them. e.g. a wireless network accessing at c200Mbps vs a nas that can deliver 80 MB/s....the latter will be held back by the network...

you may find plugging a usb hdd into your pc and sharing it is the simplest and fastest solution without having to resort to changing to a wired network in your house etc.

(Im asuming this is a home setup?)
 
Yes its a flat setup and go do it, I wanted to get home plugs.
By the looks of what you are saying guys, I will get a NAS but only as a storage for media etc to be streamed to a TV other computers.
Will keep my backup system how it is now :) (photos in 3 places)
Or maybe even cheaper would be to get good N router and just try streaming...
 
arwesa said:
love all the thechno d!ck waving ;)

for your data to be 'secure' it needs to exist seperately in 3 places. i.e. locally, on your archive and a backup.

think about your system of what is stored at each level such that its easier to only backup what you really need.

your nas (archive) will be limited by its throughput in terms of disks which is related to the type and how/if you use raid, but also the performance of the box theyre in and the network connection you have to them. e.g. a wireless network accessing at c200Mbps vs a nas that can deliver 80 MB/s....the latter will be held back by the network...

you may find plugging a usb hdd into your pc and sharing it is the simplest and fastest solution without having to resort to changing to a wired network in your house etc.

(Im asuming this is a home setup?)
Click to expand...

no willy waving at all, just different pros having different opinions.

example i think you can have secure data on 2 media as long as 1 of those is taken off site away from the first.

ive actually seen faster sustained transfer with my NAS over gigabit than a USB2 ;) but yes no doubt as several others have said its only going to be as fast as the weakest link.
 
I use my laptop/computers as my main storage and backup to the NAS.

I then have copies on 3 physical disks, but in 1 physical location. I have a external hard disk I use to backup to another location, this is currently manual, but hopefully with an internet upgrade this can also be automated.
 
neil_g said:
stream media, host raw files for lightroom.. etc etc etc..

no reason why it couldnt be your primary storage (providing gigabit cabled).
Click to expand...

500Mbit should be sufficient
 
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They don't do that speed though is my point.

You will find a 100Mbit ethernet link will probably outperform a 500Mbit homeplug link.

I have dropped most of my 200Mbit homeplugs and gone back to wireless.
 
ok,
bought WDTV media thingy today and should have it with me tomorrow.
So tomorrow, will see how it goes(streaming of movies) via WiFi..
 
neil_g said:
you need roughly 75mbps to stream HD content if i remember rightly
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That depends on the bitrate it is coded at ;) Most of my 1.5hr rips @ 720p are ~4Gbytes = 4096MBytes which is less than 1MByte/sec (or 8Mbits/sec)...
 
neil_g said:
true, assuming full fat rips :D
Click to expand...
Well, to get ~75Mbit/sec rips, you'd need more than 10x that which would bring you to 50GByte rips - which is the capacity of a dual layer BluRay.
 
In theory 802.11n should be sufficient...
I do have few 720p but couple of 1080p as well ( don't ask me how big lol )
Will let u guys know if it does its job over WiFi
 
bastic said:
In theory 802.11n should be sufficient...
Click to expand...
It is - assuming not too big a rip and you have something above "appalling" as your connection. We stream to the laptops wirelessly here and have had 2x 720p's going simultaneously.
 
google/avforums to the rescue.. an uncompressed blu-ray rip with DTS-HD stream tops out around 40~50mbps. then add in a decent overhead as you wouldnt want it rattling off the max bandwidth.
 
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neil_g said:
google/avforums to the rescue.. an uncompressed blu-ray rip with DTS-HD stream tops out around 40~50mbps. then add in a decent overhead as you wouldnt want it rattling off the max bandwidth.
Click to expand...
Yes, tops out, but not consistently. A decent prefetch buffer should sort that.

Having said that, I don't play BluRay rips without recoding them.
 
I think I need better router ;D
any ideas ?
good but not over expensive...
 
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