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Best eSATA JBOD?

Posted by timothy on from the throwing-it-out-there dept.

redlandmover writes "I already have an HP Media Server (upgraded processor, and memory) that has already been upgraded internally to 3.5TB. I'm sure everyone already has their favorite backup solution (RAID, WHS, a billion external hard drives, etc). My question is: what is the best JBOD (Just a Bunch of Drives), eSATA-connected, external hard drive enclosure? (Preferably, at least 4 drives.)"

2 of 210 comments (clear)

  1. If you need more than ten disks, go for cheap SAS by Robotbeat · · Score: 4, Informative

    You can get an external (4-port, but acts like one big 1.2 GiByte/s pipe) SAS RAID card for less than $500 that will allow you to make multiple RAID sets of up to 32-disks in a set using true hardware RAID 5,6,10, etc. You can even get a battery backup unit for the RAID card cache for $100 (priceless on critical DB systems).

    An external SAS card allows you to connect over a hundred drives through one connection using SAS expanders (some cards support up to 256 devices). Some external SAS RAID/JBOD cards have two SFF-8088 connections, for eight SAS lanes total. That's 2.4 Gigabytes/sec raw. At that rate, it's your PCI-e bus that's usually the bottleneck.

    A lot of SAS expanders are expensive, but Chenbro has some ones for $300 that spread one x4 lane SAS cable into 24 or 32 cables, plus they can be daisy-chained for more storage. Then, buy a nice 24-slot Supermicro 4U chassis with dual-redundant power. That's a little less than $1000. All you need is the Chenbro expander in the chassis, no need for a motherboard.

    If you're really cheap, you can use a cheaper $150 external SAS JBOD-only card, but hardware raid really is a must if you have a lot of storage. Plus, a hardware raid can use write-back cache, since it has effectively non-volatile RAM using the battery backup unit. And no, a UPS is NOT a replacement for NVRAM... Has your system ever crashed for any reason or hung for any reason? I've never had a RAID card hang or crash.

    So, basically, besides the external SAS card, you have:

    24-slot chassis with redundant power: $1000
    chenbro SAS expander: $300
    cables: depends

    That's about $60/slot, plus you have redundant power (and an upgrade route to dual-redundant controllers). You can scale this to hundreds of terabytes, too. Over a petabyte if you have multiple controllers (with raid array rebuilding on one card not affecting rebuilding on another).

  2. Re:I stopped reading the summary by tsalmark · · Score: 4, Informative

    RAID can be used to make two or more disks appear as one larger disk. It's nice when your backup disk is bigger than your primary disk.