Mini-Mac Server as an NAS

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I would start with a new external array rather than add to the internals. 2TB external drives are now less than $100. I would get a couple of those for data storage and a few more for backup. A program like Super Duper can manage the backups.

I have three 1.5TB drives in a concatenated array so it looks to the OS like a single 4.5 TB drive. The advantage is it is easier to manage the library but if any drive fails you lose everything on all discs. Of course you will have a backup or 2 in case that happens.

Supposedly you can add drives to a concatenated array but the one time I tried it it didn't work properly. The drive got added but it didn't add the extra capacity. I could go to disk utilities and see that the array had 3 drives but I had three 1.5 TB drives in an array with only 3 TB of space. You can't remove a drive so I ended up having to reformat those drives as a new array and restore from backup.

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No, do not make a RAID with mixed internal and external drives. It won't work. Software RAID requires all drives in the RAID set to start up within a short period of time which is very difficult to do with external drives. As soon as one external drive didn't power up in time, that drive would be considered damaged and the RAID set would be in degraded state. I have tried it before. It is very massy. Don't do it.

4TB: Wow, you got quite a music collection! Let us know how long it takes to rip that much music.

I have a couple of thousand CDs. Some of these are SACD and DVD-A and I won't be ripping these but I would like to get rid of the bulk of my collection so that I don't feel like I am living in a CD warehouse. I figure 4 TB will handle the collection and leave enough room for new acquisitions.
I kind of expect that the ripping process will take a few years, during which time I can reconnect with a lot of music that I haven't heard in a while.
What is "concancinated"?

Richard,
You can rip DVD-A discs and get the hi-rez PCM. Also, when Herman mentioned concatinated he's probably using software that acts as a "volume manager". Multiple drives can be used to present one sum-of-the-parts big drive to the user. And usually you can add drives to make the volume bigger over time.

If you plan to make a big volume of some sort and it will be over 2.2TB, make sure your O/S can handle it. I would think current Apple O/S can do it and Windows 7 can do it (and linux). And also be careful that there are new disks that are being sold now that use 4K physical sector sizes and use software in the drive to do 512 byte sector emulation for the O/S. Stay away from them. And I believe there are some type of "hybrid" drives out that have 4K sectors and somewhat large solid state caches to help overcome the performance degradation of 512 byte emulation when using physical 4K sectors. Stay away from them also.

larry

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Apple Osx disk utilities has functions built in to build disk arrays

From Mac disk utility help files

About concatenated disk sets

You can create a single, large disk from several smaller disks by creating a concatenated disk set, which is also called “Just a Bunch of Disks” (JBOD) or “spanning.” The concatenated disk set acts as one large disk with the combined capacity of all the smaller disks. You can increase the size of a concatenated disk set after it’s been created by dragging more disks to it using Disk Utility.

A concatenated disk set is helpful if you have a file, such as a database, that’s larger than any of your disks. It’s also useful if you need to create a mirrored or striped RAID set with one large disk and two smaller disks.

If all the disks in the RAID set are about the same size, consider using a striped RAID set. A striped RAID set lets you access your data quicker.

Be sure to back up your data frequently. If any one of the disks is damaged, you will lose the data that’s on all the disks.

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Wow. This is great. I will have to further investigate "concatenation" (to coin a phrase). It sounds like what I've been looking for.
Any suggested references? I wish there was a Dummies book for this (I've looked and there isn't).
Another newbie question: I understand that most NAS do not have any disc ripping abilities. My understanding is that one can use their pc to perform the rip. What I'm wondering is if the NAS software allows the pc to rip and store on the NAS without having to store it one the pc? I know that I can ultimately delete
the files from the pc, when I don't relish the thought of deleting thousands of CDs from my pc.

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You really don't need a reference, it is built into the Apple operating system.

Hook up the drives and open disk utilities. Select one of the drives and then select Raid. Name it, use the default format, and select concatenated. Drag all of the drives you want into the box and select create. When it is done you will have what appears to the computer as one disk drive that is the sum of all the drives you included.

You'll use a program running on the Mac to rip. In the preferences for whatever program you choose you can tell it to store the files directly on your array.

go poke around at these sites to learn more

http://www.audioasylum.com/forums/pcaudio

http://www.computeraudiophile.com/

http://www.usbdacs.com/

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07-30-11: Richardfinegold
What I'm wondering is if the NAS software allows the pc to rip and store on the NAS without having to store it one the pc?

The ripping program should allow the target drive to be selected from among all drives that can be seen by the operating system, including a NAS drive.

07-30-11: Larry_s
And also be careful that there are new disks that are being sold now that use 4K physical sector sizes and use software in the drive to do 512 byte sector emulation for the O/S. Stay away from them. And I believe there are some type of "hybrid" drives out that have 4K sectors and somewhat large solid state caches to help overcome the performance degradation of 512 byte emulation when using physical 4K sectors. Stay away from them also.

These are what are often referred to as "Advanced Format" drives, which are becoming increasingly prevalent among large capacity drives. The issue is that if partitions aren't aligned with the 4K sector boundaries, speed may be compromised. However,

1)Mac os's from Tiger onward, as well as Windows Vista and Windows 7 under most circumstances (i.e., if a cloning utility is not used), will correctly align the partitions when the drive is formatted, without doing anything special.

2)Western Digital provides an alignment utility for use with Windows XP and other older os's (see the links below).

3)In a NAS or other external drive application, the speed compromise that would result from misalignment is likely to be nil, because read and write speeds will be limited by the network interface (unless it is a wired gigabit ethernet connection), as well as by the cd drive during ripping, and by the audio data rate during playback, not by the hard drives in the NAS.

See the following for additional information:

http://www.wdc.com/wdproducts/library/WhitePapers/ENG/2579-771430.pdf

http://www.wdc.com/global/products/features/?id=7&language=1

http://wdc.custhelp.com/app/answers/detail/a_id/5655

I'll add that I recently installed an external (USB) Western Digital advanced format drive on a Windows XP system, without using the alignment utility, and its speed as measured with HD Tune was as good as I would expect from any USB-connected drive.

Regards,
-- Al

One more reference:

http://www.terabyteunlimited.com/kb/article.php?id=546

Regards,
-- Al

07-30-11: Almarg
I'll add that I recently installed an external (USB) Western Digital advanced format drive on a Windows XP system, without using the alignment utility, and its speed as measured with HD Tune was as good as I would expect from any USB-connected drive.

I should have mentioned in this statement that prior to performing the speed measurement I had re-formatted the drive into multiple partitions, using Windows XP, which defeats the alignment the drive was originally supplied with, and supposedly makes it necessary to use the WD alignment utility. But no speed compromise resulted, even though I didn't use the utility.

Regards,
-- Al

Al, notice there were no performance numbers in the marketing mumbo jumbo. For audio file storage, there is really no problem because it's basically sequential write once, then sequential reads. Anything that leans more towards random reads, and especially random writes, stick with "regular" drives if performance is somewhat critical or more so. That being said, these drives won't be used in "enterprise" class systems or arrays - at least the products I work on won't be using them - where performance counts.

larry

I just read the last few posts after the one I commented on. No surprise about the USB based drives showing little or no impact on performance. My original comments reflected my own experience with the drives which is not comsumer PC home use. Although, as a purist, I still wouldn't use them at home because there is still extra overhead using the drives. And since I don't have to pay for disk drives, I can use the best available... :)

larry

you can pull the superdrive and expose the sata connector and turn it into an esata and then run that to a 4-5 drive estata enclosure externally... the new lion os has the option to be a server or a workstation... your choice for $29...

Stick with Firewire on the Mac if you don't go this route... WD makes a 2 and a 4 drive external drop in drive setup for firewire.