On Mon, Jan 2, 2012 at 9:45 PM, wrote: >>> disk subsystem with 8TB of [user data] storage > > The 2U rack mount systems holding a couple of dozen disk drives > per layer would suit your application but, I think, are overkill > based on the impression I've gotten of the system you're building. > > I will restrict my comments to the storage subsystem and will > not address the server(s) that you use. =A0This project appears > to be tied to a database application. =A0In my experience, some > database engines want to be fairly tightly coupled to the disk > storage. =A0I'd research this issue once you decide on a database > system and before purchasing disk hardware. The database will be pretty much only used for user logon and store the location of a file. For example, if user x logs on, it will show him what files are available to download. When a file is clicked, the database is accessed to provide the download link (pretty much to the location of the file on the disk). > Let me outline an alternate disk system with approximate prices: > > =A0 =A0High Point Rocket Raid 2314 RAID controller =A0 =A0 =A0 =A0 =A0$20= 0 > =A0 =A0(has 4 eSATA ports with port multiplier so that each > =A0 =A0port can handle up to 5 drives in a port-multiplier > =A0 =A0aware enclosure) > > =A0 =A0Sonnet Fusion D500P 5-drive enclosure =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0$600 > =A0 =A0OR > =A0 =A0FirmTek SeriTek/5PM 5-drive enclosure =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0$500 > =A0 =A0(both have port multiplier hardware) > > =A0 =A05 x Hitachi Ultrastar 3TB enterprise class drives =A0$2,000 > =A0 =A0($370-$580 each now due to Thailand flooding **) > > =A0 =A0total cost for 9TB user space =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 =A0$2,800 > > > I would configure the drives in a RAID-5 array with 3 for data, > 1 for parity, and 1 hot spare drive. =A0I'd also ensure that the > system hosting the controller card and the drive enclosure were > on a UPS and, preferrably, in a temperature controlled room. > > This is a compromise. =A0Enclosure has single power supply and > single fan. =A0If either fail, it would be down for a while until > someone could replace parts. =A0Higher end drive enclosures for > racks frequently have hot-swappable dual power supplies & > hot-swappable dual (or more) fans. =A0Both cost money that might > not be available in the budget for this project. > > An alternate approach would be more 2TB enterprise class disk > drives in either an 8-disk enclosure (2 ports, 4 drives each) > or 2 x 5-drive enclosures. =A0Total cost for enclosures would be > higher but drives themselves would be about the same overall > cost (i.e. cost per gigabyte is roughly the same). =A0You might > have to use this configuration due to drive availability. ** > > If you have the budget, you could build out dual RAID-5 setups > and either mirror them via RAID-1 or layer ZFS on top of both. > [ZFS sounds quite nice; thanks to whoever for mentioning it.] > > ** Disk drive availability right now is a major issue. =A0I like > =A0Western Digital drives but a major part of their manufacturing > =A0capacity was put off-line by the flooding in Thailand. =A0The > =A0prices of drives have doubled since end of October. =A0And WD > =A0doesn't expect to have their plants back on-line until the > =A02nd quarter of 2012 -- and that's an uncertain estimate. =A0The > =A0lack of Western Digital product has driven up prices in the > =A0entire disk drive market due to supply & demand. =A0How fast > =A0prices return to pre-flooding levels is a big unknown as is > =A0availability of all size drives. > > If you want more specifics, or are willing to hire an outside > firm (me) to set it up for you, please contact me off-list. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .