On Thu, Jul 25, 2013 at 05:58:32PM +1000, Russell Coker wrote:
I've got a Dell Poweredge tower server running RAID-Z1 on 4 internal disks. I'd like to extend it with another maybe 8 disks in a RAID-Z2 with the option of easily adding another 8 or 16 later. The system has an eSATA connector so an enclosure that provides 24*3.5" disks with a SATA interface (not SCSI because I need SMART to work) at 6Gb/s (600MB/s) will do.
don't use esata, especially with port multipliers. sata port multipliers suck - they have all sorts of weird controller and drive compatibility issues and are unreliable garbage. http://www.zdnet.com/are-sata-port-multipliers-safe-7000011897/ https://www.usenix.org/system/files/fastpw13-paper7_0.pdf http://forums.storagereview.com/index.php/topic/28641-sata-port-multiplier-r... if you have spare PCIe slots get a cheap SAS HBA (i.e. non-raid) with external ports. 1 or two 8 port SAS cards should be able to handle 24 disks with an SAS expander in the external drive box....but since SAS expanders cost about $500 and 8-port SAS cards can be had for about $100, it's much cheaper to get three 8-port cards, or a 16-port and an 8-port. either way, the dell will be connected to the external drive box by SAS SFF-8088 to SFF-8088 cables (1 cable per 4 SAS ports) but see below about cable costs - cables are expensive, so a SAS expander (or a m/b) will probably work out cheaper.
Does anyone know of such an enclosure that's cheap? Ideally it wouldn't be excessively noisy (although 24 disks isn't going to be that quiet) because it's not a rack-mount system.
Norco RPC-4224. 24 hot swap bays. $479 from techbuy in sydney. road freight to melbourne would be about $22. http://www.techbuy.com.au/p/149123/CASINGS_SERVER_-_4U/Norco/RPC-4224.asp the supplied fans sound like the usual server fans (i.e. like a jet engine warming up) so you'll want to replace the case fans with low-noise fans, and order the replacement internal fan bracket for $12 (it allows you have two quiet 120mm fans rather than three noisy 80mm fans). figure about $20-$40 each for the fans. you'll also need a power supply and extra SAS cabling. the cables will be the most annoyingly expensive part of the project. don't buy them from techbuy or anywhere else in australia, look on ebay for cheap chinese suppliers...they're a third or less of the price of any australian importer. even so, the cables are still going to be expensive. you may find it's cheaper and better to just install a motherboard, CPU, RAM and SAS cards directly into the RCP4224 case and export the zpool to the Dell server as iscsi with one or more gigabit NICs. this will give much better performance on your regular zpool scrubs too. optionally upgrade to infiniband or 10Gbit ethernet (last I looked about a year ago, you can get cards for around $500) if you need faster connection. craig PS: i bought one of these cases at work about 18 months ago. very nice. i'd have one at home except I already had an antec 1200 tower case, and only needed to replace the antec's non-hotswap drive bays with some Lian Li EX-H34B hot-swap bays (4x3.5" drives in 3x5.25" drive slots). The EX-H34Bs cost about $80 each. -- craig sanders <cas@taz.net.au>