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View Full Version : Storing Images - Internal, External, NAS, RAID???



convergent
11-08-2006, 09:52 AM
This topic comes up quite a bit and I thought I'd give a little overview of what I see as the choices availble and where to find information. I am planning to upgrade my storage to something more capable, and this is a summary of what I've found.

As people move into digital photography, storage is something that they don't usually think through well when getting started. Often, I've seen people that don't even move the images off their flash card for months. They deal with them like film... take them to their local photo lab to get prints made from a kiosk, and often don't even save them. This is the legacy film mentality that even some of the most experienced photographers can fall prey to. My father-in-law just went on a trip to Alaska and they rented a 35 foot boat for a ten days and sailed around. They ended up losing all the digital images from the trip because of inexperience with storage, and largely trying to transition from this technique to storage on their computer.

Usually after a disaster, or after their flash card is full, people will look to get their images onto their computer for storage. A lot of the time the method chosen will be to connect the camera to the computer using a USB cable. While this works, it is usually incredibly slow in comparison to using an inexpensive flash card reader. By using a reader, the card can be removed and inserted in the reader for uploading. If you have more than one card, you can be uploading one, while still taking pictures with the other. This gets you to the much larger storage that most current compters have (in comparison to flash card sizes). The problem though, is even though there is much more capacity, the images are no more safe than being on the flash card. Once the card is reused, then the only copy of the images is the hard drive. Hard drives do fail, and in this scenario it would result in all images being lost. Imagine having 2 or 3 years of images lost.

The next step up from storing on your computer, is to use some method of backup to protect yourself against a drive failure. One of the most common methods is to back up images to CD or DVD. If this is done, then the images would end up being in two locations... on the hard drive, and on the CD/DVD. It is always good to have anything important in two places, so that a lost could be recovered. Probably the most reliable way to do this, is to make a CD of the images at the time that they are moved from flash card to computer. If this is not done, then I've found that it is easy to forget about doing it for months, in which case a drive failure would leave you with a lot lost. The problem with doing it at the time you load the images from your cards to the computer is that it takes a lot more time, and I'm not patient with this stuff.

An alternative to the CD/DVD backup is an external hard drive. These have dropped in price quite a bit in the last few years and now you can get a drive around 160GB for under $100 (if you watch the sales). External hard drives are very fast and easy to use. You connect them to an available USB port, and they will automatically be mounted for immediate use (Windows XP). You can then just drag and drop your image folders from your computer's hard drive to the external drive, and in a few seconds your most recent images will be backed up.

This is a point where many photographers can probably stay for a while. Using a combination of their hard drive, an external drive, and supplementing with backups on CD/DVD, a very safe and reliable storage workflow can be developed. The thing is though, that this approach still requires the individual to remember to copy and backup their images. If they forget, then there is an exposure for loss. There is also a limit to what can be done here. Most peoples computers tend to be loaded up with clutter, and although they may have a lot of disk space, it is usually full of stuff already. If not, then it quickly becomes full from images. On a computer running Windows XP, as the main hard drive begins to get full, then strange things start to happen with performance, and ultimately if the drive does get completely full then you won't be able to do anything.

Many homes and offices now have multiple computers in them, that all need to access the images. Together with the problems described above with space on your computer, there is another class of storage that has been becoming very popular just in the last few years, for home use. These are NAS or Network Attached Storage. A NAS is a specialized file server that connects to the network. Many homes now have networks, and while you can use Windows XP file sharing to make your images available, a NAS is a much better solution. A NAS device contains a slimmed-down operating system and file system (often some form of Linux) and supports comment file sharing methods used by Windows XP, Apple, and Linux systems. The NAS allows additional storage to be quickly added by plugging it into a network hub or switch. NAS devices range in price from under $200 to $xxx,xxx and higher for large business systems.

Entry level NAS devices look very similar to external hard drives. SimpleTech has a device called the SimpleShare which is a NAS, and a SimpleDrive which is an external USB hard drive. They look nearly identical, if not for the ethernet port on the back of the NAS. I have had good exerience with the SimpleTech drives and they frequently go on sale at places like Sams and Circuit City. A basic NAS provides no more data security than an external hard drive, but does provide easy access to all computers on the network, to your images. You plug it into the network port, and then configure it using a wizard or series of menus. Usually the device comes with a CD with software to manage the device, OR, you manage it through a browser by accessing it on the network. These devices usually have the ability to create multiple file shares (folders) with different security. They sometimes have an ability to setup automatic backups, either from your computer to the NAS, or from the NAS to some other device.

Performance is a consideration with using external devices for storage. Usually the fastest storage is your internal hard drive on your computer, followed closely by an external USB attached hard drive, if the device supports USB2. Note that USB1 devices are much slower than your internal hard drive and should be avoided. This holds true with flash card readers as well. The USB2 flash card readers, along with a high speed flash card load to your computer much, much faster than USB1. Now, that said, there is a vast difference in performance of using a NAS device, when compared to a USB2 attached hard drive. Most home LANs run at 100Mbps (1 BIT per second is 1/8 of a BYTE per second in speed, so 80Mbps = 10MBps ... usually a "b" means "bit", and a "B" means "byte"). USB2 is spec'd at 480Mbps. USB1.1 can run at 12Mbps or 1.5Mbps, so painfully slow in comparison. Some external drives also support a Firewire attachment which can be Firewire400 at 400Mbps or Firewire800 at 800Mbps. The point being that any of the above is quite a bit faster than LAN speed. These are all rated speeds, and actual throughput can vary greatly from rated speed.

So what does all this mean? It means that your basic LAN attached device, best case, can only run at about 1/5 the speed of a USB2 device. That means that if you need to move 100 images, then you could move 100 images 5 times on one device, vs. once on the other.... thats a huge difference if you deal with a lot of images. We'll come back to the LAN speed question in a moment, as there is a faster LAN option that is just now becoming popular.

Lets focus on security again for a moment, as the real power of a NAS is there. Many NAS devices offer a real time mirroring capability called RAID. There are actually different RAID methods that do totally different things, but the point is that this is one of the main reasons for getting a NAS. It should be noted that you can also implement RAID in your PC, buy getting an adapter card or motherboard that supports it. The problem is, that having everything in one box can be complicated... and is more the realm of do-it-yourselfers... who probably don't need this tutorial to help them. If you are a photographer first and want a box that works, then a standalone box is a simpler solution... and cost wise you don't usually save much in building your own anyways.

RAID stands for Redundant Array of Inexpensive Disks... a mouth full. In layman terms, it is a method of using a collection of hard disk drives together as one big drive with greater capability than using them alone. There are different RAID levels and I'll describe a few of the more common ones here. RAID Level 0 has nothing to do with data security, and in fact decreases it. With RAID Level 0, you take two hard disks and treat them as one big disk. The capacity is roughly equal to 1x... so with two 100GB drives, you'd have 200GB. What happens is that the drives are striped. As data comes in, a bit of it goes to one drive, then a bit to the other, then back and forth. This lets you effectively double the throughput of the drive. The problem is that if either drive fails, you lose everything. RAID Level 0 is often used for high speed streaming, as in video recording. It is typically not used for permanent storage.

RAID Level 1 is a simple mirroring scenario. For many photographers, this is exactly what you want. You have two drives configured for 0.5x capacity... so with two 100GB drice, you'd have 100GB. You setup the mirror in configuration menus, and then as data is written to the drive(s), internally the data is also automatically written to the second drive. If either drive were to fail, you'd still be OK. The SimpleTech SimpleShare NAS has a single drive internally, but has a couple of USB ports that allow you to connect a SimpleDrive and configure it in a RAID Level 1 configuration. I have 3 of these pairs running now and they work great. For many photographers, this is an ideal setup providing security and capacity. SimpleTech offers these in sizes up to 500GB.

As capacity goes up and you go beyond two drives, you have more options. One of the most common RAID levels is RAID Level 5. You need at least 3 drives to implement RAID Level 5, and the way it works is that you get x-1 capacity, with the ability to lose any single drive and not lose any data. So if you had four 100MB drives, you'd have 300GB capacity, with full recovery from a failure of one drive. With RAID Level 5, many NAS devices also add the ability to do a "hot swap". With hot swapping, the NAS would identify a failing drive and allow you to replace it without shutting down the NAS. Everything would continue to be available while the NAS rebuilt the failed drive. The only downside is that if you lost 2 drives, then you'd lose everything, but this is very unlikely if you were prompt in repairs.

Now lets get back to the LAN speed question. There is a Gigabit LAN option avialable. Most switches and adapters only support 100Mbps, but some... usually designated as "gigabit"... support 1000Mbps. If you recall, USB2 is spec'd at 480Mbps, so a gigabit LAN could be twice as fast in theory. The reality is that real life implementation usually doesn't run that fast, but its still 10x what standard LANs can do. The real disappointment, as you look specifically at NAS devices is that many of the entry level NAS boxes that support gigabit are not much faster than the ones that don't. It is almost a marketing thing that they say they do, because the speed tests don't show it. In fact, I've seen benchmark data of some gigabit NAS devices that come in slower than my SimpleTech 100Mbps devices. That is a real disappointment. The good news, however, is that if you get out of the very basic devices, you do find some that run pretty fast.

From my research, I've found that the Thecus N5200B NAS is about the fastest one out there at present. It has 5 SATA drive bays, capable of up to 750GB drives each... which would be 3.75TB of storage, or 3TB in RAID 5 configuration. WOW! Benchmarks done by TomsHardware at http://www.tomsnetworking.com/nas/charts/index.html?chart=133 - showed real life performance around 300Mbps for read/write times with this device, only being bettered slightly by "build your own" boxes. In comparison, the fastest drives out there are only pumping out about 500Mbps throughput by themselves (internal), so this is pretty good stuff for a LAN attached device.

So, what would you need to implement a gigabit NAS? You'd need to make sure that all your computers had a gigabit capable ethernet adapter. These are usually pretty inexpensive at around $30. Next you'd need a good gigabit switch. You can find a home class switch for around $100-200 depending on the number of ports you need. Dell's PowerConnect 2716 is a great value here that is on sale this week for $188. It is a managed 16 port switch with jumbo frame support (To get the most speed out of a gigabit environment, you need jumbo frame support... and all the devices must support it in order to implement it). Beyond that, you'll need a NAS that supports gigabit and you are all set. Just make sure you check the benchmarks on that gigabit NAS, as I've seen many that perform no better than non-gigabit units.

I think I'm going to be going with the Thecus N5200B NAS. There are a few others out there in the same price range from Infrant Technologies, Synology and Buffalo... but the Thecus seems to have much better performance and plenty of features. The only downside of the Thecus is that they are a Taiwanese company so support could be tricky. I did find a great reseller for these though. In my research I found a strong recommendation for the Thecus, and to buy from eAegis.com. Following that recommendation, I sent an email to them with a few questions. Within an hour I was able to get on the phone with someone there that walked through all my requirements and questions. They explained how they help support the device, and also that they burn-in any NAS that you order for 48 hours an configure it so its ready to go when you receive it. This is the configuration I'm considering, although I'll probably go with 3 drives to start, rather than 4. With 5 bays, I can add two drives later as my storage needs grow... and the NAS will automatically add them to the RAID5 storage pool for me and not miss a beat.

http://www.eaegis.com/Browse_Item_Details.asp/Item_ID/954731/categ_id/115/parent_ids/0,3,34,64,115/Name/THECUS_N5200B_NAS_20TB_(4x500GB)_WD5000YS_Hard_Dis ks_5_x_HotSwap_Disk_Trays_RAID_015610_JBOD

trolleycar
11-08-2006, 11:01 AM
HI convergent
Thaks for the info about image storage . I have been looks the info that you just listed. does raid 5 make a second copy of the data at the same time like raid 1 does. At the present I am making three copies of the data one on a external 100GB laptop drive for use on my laptop and two copies of two external 500g drives connected to the Darkroom Computer. plus in the field as soon as the CF card is full I make a Copy on my Epson P400. I am looking for a way to cut down the time to backup the data. do you still think that you should make the copy on the CD/DVD as well.

Bob C

convergent
11-08-2006, 11:35 AM
RAID5 uses parity bits and some technical magic to make a duplicate copy of the data. It is not a simple mirror though. The basic situation is that if any one drive fails, you lose nothing. If two drives fail in the array at the same time, then you lose your data. As long as you replace a drive if it fails, then you should be fine. That said, I still backup to DVD about once every couple of months though... that way if there was a catastrophic failure then I wouldn't lose everything. The DVD thing is easier for me if I just do a big backup in that interval, vs. having to do it every day. RAID1 is a true mirror... everything on one drive is mirrored to the other. So to grow your space, you need to add a new pair. So you ultimately get more capacity from RAID5 since its N-1, vs N/2 effective drives. With 4 drives in RAID1, you'd get an effective 2 drives worth of space. With 4 drives in RAID5, you'd get an effective 3 drives worth of space.

TomNanos
11-08-2006, 12:04 PM
Very good look at things, Mike!

One other thing to consider in the realm of external drives - Firewire (aka IEEE 1394). There's two flavors - FireWire 400 and 800. Each are 400Mbps and 800Mbps respectively. USB2, in high speed mode, can do up to 480Mbps, but the catch here is in the actual arcitecture itself. USB uses your comptuer's CPU to manage data transfers, while FireWire is designed to have the devices themselves (hard drives, scanners, cameras, etc.) manage the data transfers and conflict negociation themselves, freeing up your CPU. So you may have more bandwidth with USB2, but you get better throughput (actual data moved) with Firewire.

Right now I use a combination of drive mirroring and DVD backups. I've only got one RAID-5 array in the house, and that's about to go onto my web server - it's an older Compaq Fast-Wide SCSI hot-swap array from an old server I picked up on eBay a while back - it'll only end up with about 12GB of storage - but that's plenty for my websites. Anyways, I'm at the point now that I really need a better, more efficient storage scheme. I think my next step is to build my own NAS. I've got my old webserver kicking around (Dual Pentium III 450MHz with about 384MB of RAM), and a couple hard drives. I'm planning on building it up into a RAID-5 array using IDE drives, all running on Linux, and having the OS do the RAID management (yeah, a dedicated RAID card would do better, but the one I've got is a bit flaky, and software RAID in Linux is pretty slick, able to email me when a drive goes bad). Only thing I really need to purchase is the gigabit ethernet cards and a crossover cable. I'm not going to bother with a switch right now since I'll only be attaching it to one machine. Most of my machines are on a wireless network (802.11g), so I'd have to string Cat5e everywhere in the house - something I don't need to do right now.

convergent
11-08-2006, 12:15 PM
I ended up going back to wired for most things in the home/office, because moving images around over a wireless connection is just too painful. I also store everything on the NAS. I even have My Documents remapped to the NAS so the only thing on my computer is the OS and applications.

TomNanos
11-08-2006, 12:20 PM
No real magic in RAID-5. Basically the data is chunked up into blocks (size varies depending on how your array is set up - usually between 16 and 64kb), then written to each disk in the array. When it gets to the last disk in the array, it computes a parity value and writes that to the last disk. What the parity value gives the computer is a way to recover one missing block of data. So if you lose a disk, it can reconstruct all the missing data. The other thing that the array does is it shifts the way it writes the data to the disks, so all the parity data isn't residing on one disk.

Here's a pretty good explination, along with some graphical representations of what's going on, up on Wikipedia:

http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks

RAID5 can get expensive to set up, especially when you're using SCSI disks (last much longer than IDEs), but it is good insurance for saving your data if a single drive fails. You lose two drives, however, and you're hosed. That's why you still need another backup scheme, even with RAID5. Remember, it's called a fault-tolerant system, not fault-proof. Any good backup scheme relies on multiple backups - the old don't put all your eggs in one basket addage... :D

convergent
11-08-2006, 12:49 PM
I think most of the newer NAS boxes use SATA drives, as opposed to SCSI or IDE... not sure what the technical differences are. A couple of things to consider when buying vs. building a NAS. Most of the NAS boxes are pretty slimmed down so that should minimize the chance of failure. They also allow drive spin down on idle... which can greatly increase the life of the drives, vs. keeping them spinning 24x7. I don't know if thats available with drives in an array in a normal computer. I am seeing different drives too, that are specifically designed for use in RAID arrays. They are spec'd to higher standards, and even have different firmware. For example, the drives I'm looking have a different error handling mechanism for RAID... giving much less time for the drive to fix an error before giving up. This helps avoid the array thinking the drive has failed and taking it offline, vs. reporting the error and letting RAID take care of that. I probably didn't describe that technically accurately, but the concept should come through. Finally, from what I've seen on TomsHardware's DIY NAS builds, it doesn't really save a lot of money to build your own, but you do get a few bits of performance in some benchmarks. The Thecus comes darn close though, and it has hot swappable drives too. Another point of benefit is power consumption, with the dedicated NAS saving operating costs. Finally, having a supported dedicated box should ultimately be more reliable and reduce the risk of an outage vs. building your own and possibly making a mistake which results in unrecoverable failure.

I agree that you should still have a good backup scheme, but together with RAID it gives you an excellent first line of defense.

TomNanos
11-08-2006, 01:19 PM
SATA and ATA drives are identical except for the connectors and the little circuit board on the bottom of it - internally they're IDE drives. The difference is the interface - SATA is a Serial data transfer format (data is sent over four wires - two to the device, two from the device - in a stream), and ATA is a parallel (data is sent over 16 seperate wires at the same time). The one key advantage of SATA, and why it's used on newer RAID arrays, is that it has a native capability to be hot-swapped. SCSI arrays need to have special enclosures to handle hot swapping (not powering down to pull the drive). Spin down when idle is fairly easy to do at the OS level (it's a function of the machine's power management), and is a good idea on IDE drives (SATA and ATA).

As for building your own vs. off the shelf - that's a personal preference. For me, I've got tons of crap laying around that I can start with, and with a minimal outlay of cash, I can get a working, and somewhat speedy system up and running. As for support - honestly, I've never had a need to use it. I do this for a living, so I'm fortunate to have the tools and experience at my fingertips. Plus I love the challenge of building something and getting it running. Again, a personal preference. I'm not saying that everyone should build their own - I'm saying that 9 times out of 10 I'll build my own. :D

I am curious about one thing Mike - can you give me a model on the RAID optimized drives you're talking about? I'm interested to see what they do different, and what the specs are....may want to drop them in my machine... :D

convergent
11-08-2006, 01:50 PM
I tend to build my own stuff too, but lately I've been looking at the amount of time I have available, and what I want to spend it on. ;) I have definitely not saved any money by building my own stuff over time. There is a bit of personal satisfaction when you get it running though.

Its interesting about the drives. I have kind of moved away from Western Digital as I had trouble with them way back years ago. The company I'm talking to about the NAS primarily uses Maxtor drives in their configurations, but this particular "enterprise class" drive they like is from Western Digital. It also tested very positively at TomsHardware, and was so quiet that I've seen some people complain that its too quiet! Check it out here... this page gives a lot of information about how they are different from regular drives... http://www.wdc.com/en/products/Products.asp?DriveID=238

TomNanos
11-08-2006, 02:08 PM
Thanks Mike! Very interesting....may have to look deeper into these drives.

Holland_patrick
11-08-2006, 05:05 PM
My head hurts...:drool


I'll have to come back to this..


good reading..
:tw

Orgnoi1
11-08-2006, 05:37 PM
Great read guys... going to read it over again later... I am VERY naive to RAID arrays so this is definately an eye opener without having to run around the web to look it all up. I guess in never using RAID, RAID5 is kinda scary to me... maybe more because of the unknown. It pushes me to think I would need more RAID1 and have full redundancy, especially with the amount of repairs I have undertaken lately in my network. It is definately more costly for Room Vs. $$$ though...

That link you posted Mike to the array I really like. It caught my eye for sure, and not really too hefty of a price for 2TB of room if it was run RAID1... I will have to carefully consider it...

convergent
11-08-2006, 05:53 PM
Well its amazing the timing of things. I've been looking at NAS boxes for weeks, and just kind of decided on the Thecus N5200, primarily driven by the TomsHardware performance results. Well, right after I posted this, TomsHardware posted their full 12 page review of the Thecus. They basically gave it a thumbs down, even though it is much faster than everything else. The reason is the fear of quality control issues and total lack of support. In contrast, I've started looking at Infrant's ReadyNAS NV+ which can be found here with 3x500G drives - http://www.eaegis.com/Browse_Item_Details.asp/Item_ID/985391/categ_id/130/parent_ids/0,3,34,64,130/Name/Infrant_ReadyNAS_NV+15TB(3x500GB_Seagate)_pre-installed_HDDs_X-RAID_RAID_5_256MB_memory_Silver_Small_form_factor_ desktop . The ReadyNAS is still a good performer, but just not as fast as the Thecus. Infrant has a great service record and good support. They even have their own support forum and wiki, and directly participate in other forums such as AVScience. They even have a Digital Photography category in their forum, although its only got a hanful of threads in it.

From what I can gather from the relative performance results at TomsHardware, the ReadyNAS is going to outperform my existing SimpleTech SimpleShare NAS boxes by about 4-5X, so that should be plenty fast. The ReadyNAS also supports a lot of media server type things that the Thecus doesn't, even though the Thecus supports more RAID types and has other features. But, if the stuff doesn't work right, then what good is it.

Another feature I like about the ReadyNAS is it can be configured so that you start with a single drive, then add a 2nd, then a 3rd, etc... and it automatically expands. It will even let you put in larger drives and grow (with exceptions). Most of the other NAS solutions don't allow this.

I guess the bottom line is that the whole reason I'm doing NAS in the first place is security of my data, so I need to go with a company and product that are solid and reliable, vs. the one that is the absolute fastest available, right?

Ross, I wouldn't be afraid of using RAID5. It is the most widely used RAID out there in the business world I believe. RAID0 (the striping) is the one that is kind of dangerous. I had a RAID0 array in one of my computers here at one point, but it was used strictly as a scratch disk for video capture streaming. Once I was finished editing, it got saved to something else. RAID0 essentially doubled the disk throughput though, which I needed at that time (years ago).

convergent
11-08-2006, 07:39 PM
Well, I pulled the trigger and ordered an Irfrant Technologies ReadyNAS+ and 3x 500GB Seagate Barracuda 7200.10 drives. I should be able to configure this as about 1TB of storage. I also ordered a Dell PowerConnect 2716 Managed Gigabit switch. Both support Jumbo Frames, so now I just need to get some adapter cards that support same and I should be flying.

I also discovered this thing can stream media to devices on my network. Their forum is a wealth of info. I can get a DVD player for about $250 that has an ethernet port on the back that supposedly will let me browse my NAS and pull down photos, music, videos, or whatever... very cool. My wife will be all over that since she hates computers.

TomNanos
11-08-2006, 11:52 PM
No need to fear RAID5 - it is very widely used, we've got 'em all over at work (actually, lately we're using more and more SANs - Storage Area Network - essentially a cluster of RAID-5 servers, and are in the hundreds of terabyte range) and is quite stable. RAID-0 is only for performance increases and short term storage - never for fault tolerant storage. RAID-1 does make an exact duplicate (mirror) of the data, but is an inefficent way to store data.

Just finished throwing a 7 drive 12GB SCSI RAID-5 array on my webserver and cut over all the websites to the array. Got the system monitoring the array, and any problems with the drives will get emailed to me within a minute of it happening.... Building another 5 drive array - ripped the hot swap drive cage out of an old Compaq ProLiant server I've got in the basement. Just need to get a power supply for it, and I've got another 8GB RAID-5 array.... Yep, I'm a geek and I'm proud. :D ;)

As for them going belly up on you - get high end drives (enterprise quality, like Mike mentioned previously) - they'll last longer. Plus with RAID5, even if you lose one, you're still good, same as RAID-1. And with RAID1, if you lose two drives, like RAID5, you're done, so why not go for the more efficent storage method, as well as the higher performance of RAID-5?

convergent
11-09-2006, 03:33 AM
There are actually some benefits to RAID1 too though. In a four drive configuration, you'd only get 1/2 the capacity... or that of two drives. But, you could lose 2 drives in this scenario and not lose everything like with RAID5. You'd either lose half of your stuff, or you'd lose none if you were fortunate enough to have one drive from each 2 drive array fail. The preferred method is RAID5 though, as Tom said.

Now that I've got this thing on order, I've been looking into all the media serving that it can do. It integrates out of the box with many server apps like iTunes, UPnP, and others. I understand most of it, except for the DVD library. When you RIP a DVD, you get a bunch of files. I haven't figure out how they'd be stored so that you could access them from a media appliance. I guess I'll play with it when I get it. I can see this is going to cost me a lot of money if I get into this media serving thing.

convergent
11-09-2006, 03:21 PM
I probably should start a new thread for this, but it is related so I'll keep this one plodding along. Now that I've got this cool hardware coming, I'm now thinking I need a real DAM (Digital Asset Management) software solution. The contenders are iView Media Pro, ACDSee Pro, Camera Bits PhotoMechanic, Extensis Portfolio 8, Adobe Lightroom, Apple Aperture, Cerious ThumbsPlus Pro, Photools IMatch, and BreezeBrowser Pro, to name a few. So far, it looks like the only ones that remotely support shared use... i.e., having the database on a NAS or server, and then letting multiple workstations acces it... are Portfolio, ThumbsPlus and IMatch. For a couple of computers to use Portfolio, you are talking about over $6K, so that one is out for my needs. I will be looking at the other two a little closer to see which one I like best. Luminous Landscape gave very high marks to IMatch, and many users in a thread at POTN also gave it recommendations.

Ironically, IViewMediaPro is one of the most used tools by pros, but absolutely doesn't work well at all on a shared setup. Aperture and LightRoom I think may eventually get there, but they are both very imature products at this point. One good thing is Microsoft w/Media Pro, Apple w/Aperture, and Adobe w/LightRoom will be duking it out in this space for years to come. We can only gain.