Network Attached Storage — What the Heck?

March 18, 2012 by  

On the podcast #112, Tim (Robertson) and Guy (Serle) discussed NAS (Network-Attached Storage) devices, and having worked with them myself, I thought I’d share my experiences.

My department purchased a Quantum SnapServer 4000 back in the mid-late 1990s, when our existing AppleShare server began showing some weakness handling the ever-increasing amount of content we had to manage in a technical publications organization (we filled up our two 1 GB hard drives…). the SnapServer had four 30GB drives in a RAID5 configuration, meaning after overhead and such, we had about 84 GB of storage available.

We ran a mixed-platform (Mac/PC) operation, but because we started as a PC organization well before Windows 3.1 graced us with its presence, we were all very used to using short filenames (the DOS 8.3 standard: 8 character file name and a three character file extension). When most of the users in the department moved to Macs, they still retained the mindset of using short filenames, which was real handy, as the SnapServer (this is the point I’m meandering toward) could only handle 31 character filenames when supporting the AFP (Apple File Protocol) standard.

We continued to use the SnapServer after we were forced to migrate to Windows NT, but thanks to disciplined filenaming conventions (and keeping file paths relatively short–that was a problem, too!), it worked well enough. I will give it credit: we never lost one byte of data, even when one of the drives took a bad dump. RAID works, friends. RAID is your friend.

In my experience, most NAS devices share common OS and file system storage roots. To this day, most NAS devices that support Macs do so with “extensions” to the older AFP (Apple File Protocols), adding OS X compatibility, but not completely supporting the newer Apple standards. This means it supports OS X (my employer had to pay Adaptec, who bought the SnapServer product line from Quantum, several hundred dollars to purchase a firmware upgrade to add OS X compatibility to the SnapOS), but it still can’t handle long file names (or names with “illegal” characters–more below).

When the evil IT folks forced my department to bid adieu to our SnapServer (they said it was a security risk because they didn’t know what was inside–and it didn’t fully support Windows 2000 Active Directory, so they couldn’t manage it), I signed it out for use at home as a media server. I replaced the farming thresher loud 30GB hard drives with virtually silent Seagate 200GB drives, and that’s when I rediscovered the filename size restrictions (not to mention restricted characters used in filenames). I got errors galore when I tried to drag copy my iTunes library (about 12,000 files) over to it, so I tried using FTP (file transfer protocol), which worked silently and effectively, or so I thought. After a day-long file transfer session moving over nearly 60 GB of content, I looked inside the various directories and found that the SnapServer had taken some really interesting liberties with my filenames. Heavy sigh!

My next project is to remove those four silent 200 GB Seagates, replace them with the noisy-as-heck 30 giggers it originally came with, and bring the bloody SnapServer 4000 back to my office, as it’s useless to me. It’ll probably get donated to a school or something like that.

To be totally fair, it’s quite possible that newer versions of the SnapServer NAS devices have improved operating system software, and the filenaming issues might be moot.

Most NAS’s will have this problem. Most of the NAS manufacturers say they support Macs, and yes they do–to a point. They cease supporting Macs when filenames exceed about 28 characters, when filenames have slashes and several other “illegal” characters in them, and I’m sure there are plenty of other incompatibilities.

Another option is to use OS X’s built-in Samba support, which emulates Windows. That would take care of the filename size problems, but not the illegal character restrictions, path name lengths, etc. Heck, I think the only restricted lower ASCII character in the Mac realm is the colon character, because Apple used to (and maybe still does) use the colon as a directory divider (like the backslash in Windows). There was also another character that interfered with Sony floppies if memory serves, and finally, you couldn’t put a period as the first character in a filename, but that’s also a Windows/DOS restriction, and a special-case usage in Unix (it’s how you hide files, IIRC).

Something else to watch for–on some RAID NAS devices, RAID 5 is only supported in software, meaning it can run a lot slower than RAID 0, 1, etc., which are usually hardware-based. The Buffalo TeraStation suffers from this performance handicap. Buyer beware.

While attending the Macworld Conference in San Francisco last week, I saw a possible answer in Axentra’s new HipServ. I spoke at length to the fellow manning the small booth and found the HipServ. It’s a 4 disk RAID array with 1 terabyte of storage, housed in a fairly small box (I don’t know how quiet, as the ambient noise in the hall made it impossible to judge). It is powered by a well-regarded distribution of Linux (he asked me not to say which one), which is automatically updated by Axcentra as required. Full details aren’t out yet, but he did say the server piece (there are a number of optional software components that can make the Hipserv the centerpiece of a media server) will cost around $900, and is claimed not to have the filename length problem described above. I’d still ask for a money-back guarantee, but the Hipserv is an attractive package, competitively priced, and might just do the trick as a media server, file server, and backup storage device.

So, a RAID-based NAS is a great way to safely store large amounts of shared data, but Mac users need to beware of filenaming issues and need to ask those questions.

Other options include making one of your old Macs a file server, or if you feel really adventurous, build a Linux server. Windows Server 2000 and 2003 support AFP, but share similar filenaming issues to the older NAS devices (I ran Windows 2000 Server at home on an older PC for a long time, but finally got tired of all the shortcomings (filenaming, mainly).

Author’s Note: Well, here’s the rest of the story. About two years ago (this supplement was written in March 2012), I bought a Synology DS-509+ with five 1.5 TB drives for a total capacity after RAID and system overhead, of around 6 TB. Last year, I bought the companion Synology DX-5 slave unit, which I loaded up with five 2 TB drives for a total, again after RAID and system overhead, of about 8.5 TB. I back up the DS-509+ to the DX-5, and back up my workstations and laptops to the DX-5. This has turned out to be a very useful investment, and with the RAID5 disk formatting, it also saved my behind when one of the drives in the DS-509+ failed. Thanks to RAID5, I was able to remove the defective drive, install a new one, and within 8 hours, all of the data that was on that disk was restored to all its former glory. My main purpose is to use it to store backups of my DVD collection. The backups are used with my media server software. This, too, is another story for another time and another category.