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Question: What is the largest volume size that I can have?  If I have the 1218, and 2 extenders all with 4tb drives, can I have one volume with them all in it?
Document: If you wait and don't reboot, it will show the second one needing to be installed to.I created the folders and started the network copy, got speeds of 75-80 megs. Once complete I added 2 more 2tb drives. Add them and tell it to extend the volume. With the additional drives I am looking at around 50-hours for it to complete. Once done, will add 3 more 2-tb drives for a total of 8.
It only wants to install a newer image, and such is not available.Purchased and installed 8 of the supported 2 TB Samsung disks, which I also use in my ReadyNAS boxes. Used Synology Assistant to install the 2228 build of DMS 4.0. The initial install appeared to succeed. I deleted volume 1 and created a new one, using SHR2, for two disk redundancy. I also installed a CrashPlan package after building the SHR2. At some point after that, the box appeared unstable.
It should be noted that you can not do a disk migration from a single drive redundancy raid to SHR 2 drive protection. You will have to move the drives to the DS1812+, delete the volume and then go through the painstaking process of copy all your files the server.I have a large media collection that spanned 3 smaller back-up drives.
Synology makes two basic network attached raid systems. The DS is more of a low power, desktop size, unit great for small offices to share documents, and mount network disk drives on everyone's pcs. The RAID 5 feature means even if one of the 8 drives fails, you will not loose ANY data. BUT you need to replace the failed drive fast with an identical drive (hint buy a 9th drive and make sure it works, then keep it in the box).
One drive was found bad and waiting for my replacement from Seagate. The good part is it still used the drive as it had not failed.Very impressed with the speed and complete software. At this point I would buy one of these again.My HTPC is hooked up via a 2 path 1 gigabit switches. Hard wired cat5 cable. When pulling video and audio, the response is pretty instantaneous. I was unable to detect any lag. The largest file I tried was 10 gigs, no stuttering.
I have been looking at NAS units for years for clients and perhaps one day myself, and alas I recently got serious about replacing my hodgepodge ofWestern Digital WD Elements 2 TB USB 2.0 Desktop External Hard Drives with a permanent solution.
After a year of use I can honestly say this is one of the best purchases I have ever made. The DS1812+ is a versatile piece of hardware due to the software services available. I loaded my DS1812+ with 8 Seagate Constellation ES 2 TB drives, placed it in well ventilated area, set up the services I needed, and it's been running perfectly ever sense.
I bought this unit to back up all of my family's computers, as well as store our inventory of music, movies, photos, etc. I filled it with eight 3TB Western Digital "Red" drives. It was very easy to set up, including the installation of the drives. It comes with everything one needs to install eight 3.5- or 2.5-inch drives (drive rails, screws, etc).
I purchased my DS1812+ last week Friday. I had 3 2-tb drives ready for install. They plug and play pretty easy. Install of clean drives took about 30 minutes and was simple with the browser interface. Install, add folders and shares, and then ready.One issue, with 2 network cables hooked up, the software shows 2 connections with 2 I.P. addresses for the Dockstation. It then is ready to install the software to the Dockstation. Install to one and reboot.
I'm not going to return the product however I wish I should have got more from this box.Few issues:-1. Extremely slow to build Volume2. Extremely slow to add harddrive to disk group for SHR1 or SHR23. During Volume or disk group build process, NFS is very slow4. Can't reboot machine when volume build is going on - if it goes on for 2 days for 2 days you can't restart!
Answer: I don't believe there is a volume limit and I certainly made one volume using 3TB drives across 1 extender, but I can tell you that I wouldn't do it again.  I wish I made the extender a separate volume.  If a drive dies and you replace it, you've got a full rebuild to do which will be that more intensive and if another drive dies in that process, you've lost everything.