NAS or DAS?

[Mindprey]

So my iTunes library is starting to grow out of control in size (mostly due to my movie collection). I only use the Mac Mini as a server essentially, and all pertinent data and iTunes are on an external hard drive. I'm considering a storage increase, but am trying to figure out if going with a NAS is better, or a direct attached storage. I want to run some kind of Raid configuration so that I can keep a duplicate copy of my library, and I would like to have at least 8gb available.

I have heard nightmares with NAS and iTunes, and I know there are also downsides to DAS as well (or rather limitations).

Can anyone comment on their experience with NAS and iTunes? Any recommendations for a 4 bay NAS or DAS from current users?

 

[tmanto02]

So my iTunes library is starting to grow out of control in size (mostly due to my movie collection). I only use the Mac Mini as a server essentially, and all pertinent data and iTunes are on an external hard drive. I'm considering a storage increase, but am trying to figure out if going with a NAS is better, or a direct attached storage. I want to run some kind of Raid configuration so that I can keep a duplicate copy of my library, and I would like to have at least 8gb available.

I have heard nightmares with NAS and iTunes, and I know there are also downsides to DAS as well (or rather limitations).

Can anyone comment on their experience with NAS and iTunes? Any recommendations for a 4 bay NAS or DAS from current users?

Do you mean 8tb?

 

[Mindprey]

Do you mean 8tb?

Yeah, typo, 8tb minimum.

 

[ChrisA]

So my iTunes library is starting to grow out of control in size (mostly due to my movie collection). I only use the Mac Mini as a server essentially, and all pertinent data and iTunes are on an external hard drive. I'm considering a storage increase, but am trying to figure out if going with a NAS is better, or a direct attached storage. I want to run some kind of Raid configuration so that I can keep a duplicate copy of my library, and I would like to have at least 8gb available.

I have heard nightmares with NAS and iTunes, and I know there are also downsides to DAS as well (or rather limitations).

Can anyone comment on their experience with NAS and iTunes? Any recommendations for a 4 bay NAS or DAS from current users?

Only use NAS if you need to access the data from multiple computers that are on the same network. If you don't need that then you have no need for NAS.

Raid is NOT backup. do NOT depend on raid to save you data from a crash. The only way to prevent that is backups. You need to have at least three copies of the data in at least two geographic locations and maintain this even while a backup operation is under way.

For most people Tie Machine is the first copy and then you rotate disk drives to an off site location.

Just get an external storage system that is no more then 1/2 full on day one. Connect it directly to the Mini and if it needs t be shard the Mni can share it.

Then buy enough disks to backup the DAS system twice at least.

 

[ahughes03]

If you're strictly looking for additional storage space, there's really no reason to go NAS. Here's a link to a DAS box that should meet all of your needs.

http://eshop.macsales.com/item/Other World Computing/MEQX2KIT0GB/

The thing has a variety of connection options and variable RAID configurations. You can pick up matching hard drives from various online providers (all drives should be the exact same brand and model, ideally down to item number).

I personally have a 12TB NAS solution from Synology, set up in a RAID 5 (equaling 9 usable TBs), and enjoy having the additional features a NAS provides (email server, photo host, audio server, blog, etc). Basically, my whole movie, photo and music library is available on any computer or device that gets an internet connection.

Again, while NAS is nice, DAS will do exactly what you need if you are really only looking to increase storage space and have a little bit of "backup."

I'm sure you've read this elsewhere, but don't assume RAID is a backup. While RAID is better than nothing, RAID volumes can become corrupt during the rebuild process, meaning you have the capacity to lose everything. A true backup is something that is stored away from the original, and has limited contact with your day to day system (outside of syncs).

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Only use NAS if you need to access the data from multiple computers that are on the same network. If you don't need that then you have no need for NAS.

If you're running a mac environment, you don't need a NAS to do this. Simply enable file sharing in Preferences.

Looks like Chris beat me to the scary RAID warning!

 

[opinio]

So my iTunes library is starting to grow out of control in size (mostly due to my movie collection). I only use the Mac Mini as a server essentially, and all pertinent data and iTunes are on an external hard drive. I'm considering a storage increase, but am trying to figure out if going with a NAS is better, or a direct attached storage. I want to run some kind of Raid configuration so that I can keep a duplicate copy of my library, and I would like to have at least 8gb available.

I have heard nightmares with NAS and iTunes, and I know there are also downsides to DAS as well (or rather limitations).

Can anyone comment on their experience with NAS and iTunes? Any recommendations for a 4 bay NAS or DAS from current users?

I run 2 seagate 4tb external USB 3.0 drives in a software Apple RAID 0. In other words 8tb. I get around 280 MB/s read write. I run 2tb of iTunes from it. If I run the same drives in a hardware RAID (OWC or Guardian Maximus) I get 230MB/s on both USB 3.0 or esata on a tbolt hub. So Apple RAID is the fastest for me.

 

[John Kotches]

ChrisA:

Most "civilian" users will not go to the trouble or effort of having 3 copies of their data. You're lucky to get a backup.

I concur with your point with respect to RAID. The raison d'etre for the redundancy is to not lose data with a single drive failure. It is not replacement for a backup.

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ahughes:

A RAID array doesn't go corrupt during the rebuild. The array was corrupt before that and the rebuild uncovered it. I've seen this referred to as bit rot.

 

[famous600]

I run 2 seagate 4tb external USB 3.0 drives in a software Apple RAID 0. In other words 8tb. I get around 280 MB/s read write. I run 2tb of iTunes from it. If I run the same drives in a hardware RAID (OWC or Guardian Maximus) I get 230MB/s on both USB 3.0 or esata on a tbolt hub. So Apple RAID is the fastest for me.

I have a 4tb right now but plan on getting another and raiding. I found crashplan to be an EXCELLENT back up source.

 

[blanka]

DAS makes more noise.

 

[John Kotches]

I run 2 seagate 4tb external USB 3.0 drives in a software Apple RAID 0. In other words 8tb. I get around 280 MB/s read write. I run 2tb of iTunes from it. If I run the same drives in a hardware RAID (OWC or Guardian Maximus) I get 230MB/s on both USB 3.0 or esata on a tbolt hub. So Apple RAID is the fastest for me.

You're willing to put all your data at risk with a single drive failure?

Wow!

 

[opinio]

You're willing to put all your data at risk with a single drive failure?

Wow!

That seems a bit narrow minded to think I have 'all my data' on one RAID? Nice shooting from the hip tex. I have no idea how your read that from my post? I was outlining how to get the best speed from USB 3.0 through a software RAID option. I didn't outline or even imply it was my data redundancy plan? In fact I didn't even outline what I have on the drive apart from iTunes.

That drive I outlined is my primary high speed operating drive. I have run multiple RAID-0 configurations for over 15 years and I have found the Apple OSX software RAID is actually my fastest I have produced with my configurations. It has been faster than RAID enclosures I have bought.

However, to respond to your 'wow! I'm an idiot I have no idea' comment...

That 8TB RAID-0 is backed up nightly to an 8TB RAID-0 (GMAX) via a SuperDuper clone set to SmartUpdate. It is also backed up weekly to a 6TB RAID-0 (OWC Mercury Elite Pro Dual) that is kept off-site in case of fire/theft. So I have two copies of the drive plus the original. I also use SuperDuper and Time Machine to back up the primary OS drive. The SuperDuper image file is on the 8TB primary drive. So I have one copy of the primary HD in Time Machine (with all the multiple historic images), and one copy of the image via SuperDuper, which in turn is back up with the 8TB twice. So according to my calculations, my primary OS drive is on 5 separate drives, with one of those being offsite. I should note I have three mac minis and two MacBook airs that all follow that back system of the primary drive. So I have 5 macs with 5 copies of the primary OS drive which is 25 copies of OS X. I hold about 80gb of critically valuable files on each OS drive as well which is synced across all Macs and in the Cloud via DropBox as well. So my critical data is spread across all macs and all backup drives. Also I have 2 1TB and 1 3TB drive (3 separate drives) that are plugged in via USB to my AirPort Extreme which I use for Time Machine for my 4 secondary macs. My primary mac has its own TM drive.

So my data is spread across about 15 drives which is made up of about 20 disks of around 35-40TB as I run a number of fusion and RAID setups.

You need to think before you infer people don't know what they are doing.

 

[Zemzil]

I don't understand if 8TB is only your iTunes library or if you count it as both library + backup. But in short terms, there is no problem to use DAS disk for both data and backup, NAS is more for networking/sharing use or networking backup.

I have no personnal experience (in domestic environment) with iStuff and NAS, but most of the NAS I see mention "Airplay/iTunes server/Time Machine supported" in their spec and all suport DLNA for streaming. If you own an old Mac you can try this too for dedicated it as a server :

http://www.freenas.org

But for me, it duplicates what your Mini is, already a server. And don't forget that NAS almost never user HSF+ as drive format. The other things is that Time Machine don't exactly like network drive.


The quality of a backup is not entirely defined in the type of storage but more in the redundancy. It's more secure to have 8TB of cheap DVD-R in your grandma's closet and 12 USB no-name key in your uncle's cave than only one Cisco 25.000$ backup at your home (if I exaggerate, to be understanded).

If I have to do this for myself, at first I will use two different enclosure for online data and backup. In case of failure (included the failure of the enclosure), you have more flexibility. There are plenty great USB-3/FW800 SATA 3.5" enclosures with 1/2/3/4 drive on the market, so it's more a matter of personal choice than technical one.

Then, I will use Time Machine to backup Mini internal drive + "online enclosure" on the "backup enclosure". And at end, doing one every week/month on another different drives, to keep it in a total separated environment from my online backup system. But it's an option, the most important is to have one at first.

 

[opinio]

I don't understand if 8TB is only your iTunes library or if you count it as both library + backup.

The 8TB drive holds my iTunes library (about 2TB) and also about 4-5TB of other data.

My backup is another completely separate 8TB.

I am not so much suggesting what you do with iTunes, I was more providing a fast storage solution that is way faster than iTunes needs, but gives you good read/write on your other data transfers.

 

[Zemzil]

Question was for Mindprey, sorry for the confusion

 

[opinio]

Question was for Mindprey, sorry for the confusion

cool

 

[karpich1]

If you're running a mac environment, you don't need a NAS to do this. Simply enable file sharing in Preferences.

Looks like Chris beat me to the scary RAID warning!

While technically true (for Windows and Mac), a NAS is quite handy.

With the NAS, I don't need a host-PC to be turned on. As I often turn off my main desktop for power issues and would prefer it didn't sleep. So with the NAS, I can access my files from my laptop (via the couch) without having to worry about whether I left my desktop on.

Plus, I have friends who only have laptops (plural). Which are always being carried everywhere around the house and never permanently on the desk or something. So they love having their little WD LiveBook NAS.


BUT... for the OP's scenario a regular USB3 / FireWire / Thunderbolt external drive would be fine so long as the Mini is always on and he buys the correct drive for his machine's ports.

 

[John Kotches]

opinio:

Here's my issue with your approach:

RAID-0 with 2 disks is twice as likely to fail with loss of data between last backup and time of failure. Then you use the same approach with your backup drive, i.e. 2x the likelihood of failure, compounded by your off site which is also 2x the likelihood of failure. Is it likely that you'll see this level of failure? Nope. Most likely bad scenario is you are failing to restore from the primary backup and having to roll forward from your offsite to present.

It's nice to rattle off the impressive numbers with throughput, but in the end how valuable is your time and your data? Recovery time is time to restore from backup + time to recreate the data you lost between last backup and the point of failure.

Sorry I didn't put the -v flag on my previous post, but in case you couldn't tell I'm not a big fan or RAID-0 for any application.

 

[opinio]

opinio:

Here's my issue with your approach:

RAID-0 with 2 disks is twice as likely to fail with loss of data between last backup and time of failure. Then you use the same approach with your backup drive, i.e. 2x the likelihood of failure, compounded by your off site which is also 2x the likelihood of failure. Is it likely that you'll see this level of failure? Nope. Most likely bad scenario is you are failing to restore from the primary backup and having to roll forward from your offsite to present.

It's nice to rattle off the impressive numbers with throughput, but in the end how valuable is your time and your data? Recovery time is time to restore from backup + time to recreate the data you lost between last backup and the point of failure.

Sorry I didn't put the -v flag on my previous post, but in case you couldn't tell I'm not a big fan or RAID-0 for any application.

There is no compounding between risk factors. They are all mutually exclusive.

I hear what you are saying though.

I only choose RAId for my situation because I have to move large amounts of data and therefore need good speed. I have used RAID 5 before. The enclosure failed, I lost all data because I could not rebiuld the array. But I had a good backup (as already noted) so rebuilt from scratch.

You know you are clutching at straws to suggest my backup strategy has compounded risks. That is like saying by intrucing a single back drive you increase the risk because you intruduce another drive and the chance of a drive failure. I would have to have multiple catastrophic failures in separate parts of the city and world. Considering the offsite is not even live that is very hard. I would also need some form of major disaster thrown in there.

Anyway each to their own.

 

[Pheo]

One does wonder what happens if a data error / bit rot happens in your backup, and then that is replicated across all the backups.

Still, probably at the level where you can't do much about it </paranoid>

 

[opinio]

One does wonder what happens if a data error / bit rot happens in your backup, and then that is replicated across all the backups.

Still, probably at the level where you can't do much about it </paranoid>

Yeah, always a problem. But that is always a fundamental underlying problem with all backup strategies. If you amend/delete (accidently) your base files or they are corrupted that is replicated through.

If I ever do a complete rebuild of the master from a backup, I always do a check of the files numbers or folder size etc to check it is identical to the backups before I restart. I.e. you hit CMD i and check the figures gainst the backup to see if they match. It is not bullet proof but it helps.

Time Machine rectifies that to a certain extent by keeping multiple copies of changed files so you can go back. But I cannot run 6TB through TM as I edit it so much and I would need a progressivly bigger drive for backup.

 

[Pheo]

Sage words!

I've been wondering whether a DAS or NAS is better for me. So far the conclusion has been that DAS units eg DROBO are just too expensive - dont understand how essentially a whole computer (synology) is cheaper than a drobo mini!

Maybe they are easier to get hold of in the states but here they are expensive I think (UK)

 

[Mindprey]

Thank you all for you input and experiences. I still have a bit more research to do, but I think DAS is a better solution as I will only be sharing the media within my home (iOS devices already see the data and play it, so I think moving everything to a NAS is redundant for me).

 

[Zemzil]

I'm having an eye on this NAS (±150 € diskless) : http://koobrick.com/boxi/

Upper side seems to fit Mini size and specs (PDF) looks great (AFP, Time Machine, iTunes etc) for domestic use.

I'm just waiting a response of the manufacturer to know if it supports 4Tb drive.