Affordable disk shelves - something like the Netapp DS4243 - on the other hand tend to be reliable and give plenty of space for SAS and SATA drives. I bought a

Affordable disk shelves - something like the Netapp DS4243 - on the other hand tend to be reliable and give plenty of space for SAS and SATA drives. I bought a fully populated shelf (4 x powersupply (of which I'm only using 2, the rest are disconnected and meant as spares), 2 controllers and 24 15K SAS drives (mostly HGST, a few Seagate drives) for around €400. I'm currently running it with a number of those 15K drives but will eventually replace some of them with slower but bigger SAS or SATA drives, not so much to get more space but to save power. For now the thing runs fine, the error logs on the drives are mostly clean (2 drives with a few errors, mostly likely due to power glitches as they occurred a long time ago and have not recurred). If you want lots of space for drives with redundant power and cooling these shelves are a good value since there are plenty of them on the market which keeps prices down. I'm using a combination of striping, RAID and mirroring depending on the content, using lvm and mdadm instead of ZFS for the increased flexibility. The server itself contains a HP R410i RAID card which drives 8 internal 2.5" SAS drives, the thing could be expanded for not that much money to a 16 x 2.5" array but I see no reason to do so given the higher prices for 2.5" drives and the abundance of capacity offered by the DS4243.