Safe-storage
February 17, 2009
My Backup
I use an old 1.8Ghz dual-core machine with 4GB RAM as my Network Attached Storage. While the NAS products from Synology and QNAP are good, pricewise, a small custom built PC will outperform and be more expandable than one of these systems while still costing less (4 or more disk models only). Of course you have to factor in the price of the Operating system (You can use Linux) and power consumption. Anyways, that's a topic by itself. Basically, I've 7 hard drives on this server. One drive holds the operating system. I use Windows XP because sometimes I need to offload tasks to it such as BitTorrent (QNAP and Synology NASes can do this too), Photoshop batch jobs (mostly resizing but occasionally a large RAW conversion) and running my Nikon LS-40 slide scanner (the Nikon software likes to hog the CPU when the scan is underway for some unknown reason). The other disks are purchased and installed in pairs. I've a 500GB pair, 750GB pair and a 1TB Pair.
The disks are in pairs because I use robocopy to watch for 500 changes or 45 minutes (whichever comes first) to mirror them. That way, if one disk should die suddenly (which happened before) my data is still safe. I've dabbled with consumer RAID available on some systems and find them very unreliable. If you want RAID, I suggest going with Areca which some people I know have had up to 4TB (12 disks, RAID6) running reliably. It's not cheap and disks are cheap enough nowadays that a robocopy mirror will provide all you need (we're talking about 2 or 3 users max. RAID may offer better performance if you have larger number of concurrent users). So my 6 disks end up providing a total of 2.2TB's of space. RAID is nice because it shows you a single drive. Yes, but with XP onwards (Linux is already there), you do have NTFS junctions which are symbolic links. They allow you to create reparse points to physical disks. Basically I can create a folder called 2007 which can point to drive 2. Of course all this means a bit more management and careful setup but it's a lot cheaper that a good RAID setup plus easier to recover should any disk decide to buy the farm.
For example, a photos folder will have various individual symbolic links for the individual year's worth of photos (organized subsequently by day and shoot) but I do not have to to where the photos are physically. \\storage\share\photos\2007 can point to the storage server's 500Gb disk or 1TB disk but it doesn't matter. Of course, in my case, it does sequentially with newer folders typically being created on newer disks. With a 20-month refresh (new pair of disks every 20-months) you probably have almost no problems with disk failure plus you get to buy larger disks at economically priced points. I aim to keep 6 as the maximum number of disks (power, heat, etc) so the next disk acquisition will be 1.5TB disks and they'll replace the 500GB disks. Access speed is roughly 25-35Mb/sec over a gigabit network (tested with Canon CR2 raw files averaging 12Mb). Nothing fantastic and some tuning should improve the results but since concurrent access is not critical (I've only 3 users max), I can live with it. Faster that shuffling DVDs and still be able to backup everything on our network PCs.
I use an old 1.8Ghz dual-core machine with 4GB RAM as my Network Attached Storage. While the NAS products from Synology and QNAP are good, pricewise, a small custom built PC will outperform and be more expandable than one of these systems while still costing less (4 or more disk models only). Of course you have to factor in the price of the Operating system (You can use Linux) and power consumption. Anyways, that's a topic by itself. Basically, I've 7 hard drives on this server. One drive holds the operating system. I use Windows XP because sometimes I need to offload tasks to it such as BitTorrent (QNAP and Synology NASes can do this too), Photoshop batch jobs (mostly resizing but occasionally a large RAW conversion) and running my Nikon LS-40 slide scanner (the Nikon software likes to hog the CPU when the scan is underway for some unknown reason). The other disks are purchased and installed in pairs. I've a 500GB pair, 750GB pair and a 1TB Pair.

The disks are in pairs because I use robocopy to watch for 500 changes or 45 minutes (whichever comes first) to mirror them. That way, if one disk should die suddenly (which happened before) my data is still safe. I've dabbled with consumer RAID available on some systems and find them very unreliable. If you want RAID, I suggest going with Areca which some people I know have had up to 4TB (12 disks, RAID6) running reliably. It's not cheap and disks are cheap enough nowadays that a robocopy mirror will provide all you need (we're talking about 2 or 3 users max. RAID may offer better performance if you have larger number of concurrent users). So my 6 disks end up providing a total of 2.2TB's of space. RAID is nice because it shows you a single drive. Yes, but with XP onwards (Linux is already there), you do have NTFS junctions which are symbolic links. They allow you to create reparse points to physical disks. Basically I can create a folder called 2007 which can point to drive 2. Of course all this means a bit more management and careful setup but it's a lot cheaper that a good RAID setup plus easier to recover should any disk decide to buy the farm.

For example, a photos folder will have various individual symbolic links for the individual year's worth of photos (organized subsequently by day and shoot) but I do not have to to where the photos are physically. \\storage\share\photos\2007 can point to the storage server's 500Gb disk or 1TB disk but it doesn't matter. Of course, in my case, it does sequentially with newer folders typically being created on newer disks. With a 20-month refresh (new pair of disks every 20-months) you probably have almost no problems with disk failure plus you get to buy larger disks at economically priced points. I aim to keep 6 as the maximum number of disks (power, heat, etc) so the next disk acquisition will be 1.5TB disks and they'll replace the 500GB disks. Access speed is roughly 25-35Mb/sec over a gigabit network (tested with Canon CR2 raw files averaging 12Mb). Nothing fantastic and some tuning should improve the results but since concurrent access is not critical (I've only 3 users max), I can live with it. Faster that shuffling DVDs and still be able to backup everything on our network PCs.
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