The pundits are all saying storage should be attached through the network or a SAN, but there are still times when you just need to add storage to one or two servers. Here are five products that will fix that problem.
There has been an amazing increase in the size of relatively cheap hard disk drives on the market now; you can easily buy 160GB or 250GB IDE drives for around $300 to $500. Take some of these disks and incorporate them into a RAID subsystem and you quickly have redundant storage of 160Gb to 500Gb or more.
While on face value this may sound cheap, many people do not think of the implications of having to back up this amount of data. It certainly isn’t going to fit well on CD-RW discs, unless you have around 285 of them handy and plenty of spare time. Nor is a DVD going to help much either—you’ll need 42 of those. Even your previously trusty old DDS DAT drive may be quaking at the thought.
Food for thought
Before you rush out and buy some of these solutions to augment your flagging network storage, please stop to consider the bigger picture. For an uncompressed tape backup of say even 160GB, you would be somewhere in the relatively elite league of needing Super DLT 220, SAIT-1, or Ultrium Gen 2 backup drives. As you can see from the review here, there is very little change from $10,000 even for an entry-level 160GB backup unit, once you consider the cost of the unit itself, the tapes, and the backup software. So please be forewarned, any business worth its salt cannot rely on disk redundancy alone to provide all their data safeguarding.
Enter RAID
Until recently RAID arrays (redundant array of inexpensive disks, or independent disks) were primarily the domain of server administrators and system integrators. These days you can now find relatively inexpensive desktop system mainboards that support IDE disk RAID levels 0 and 1--mirroring and striping respectively--to provide some level of redundancy and data protection or a slight performance increase for applications such as video editing. This is RAID at its most basic.
However with the convergence of these technologies by some very clever vendors, we now have external mass storage devices that are rack mountable. These combine the RAID controller hardware and SCSI or IDE adaptors that allows users to plug in anything up to 14 standard 3.5in hard disk drives with integrated firmware to allow setup and administration to be performed as simply and easily as setting up any of the recent IT appliances designed to make administrators’ lives a breeze. (OK, fess up, who said “HA!” just then?) The majority of direct attached systems simply plug into the external SCSI port of a server and are detected and can be managed as a single disk via the traditional methods or via vendor-supplied software.
DAS or NAS?
You may also come across the terms direct attached storage (DAS) and network attached storage (NAS). DAS are units that have interface connectors on them that allow system administrators to connect them straight to the server they will be working with. On the other hand, NAS allows administrators to connect them somewhere on the local area or even wide area network and access the storage on them remotely. (Click here for a recent review of NAS arrays.) The third most commonly used term for external storage is SAN, which stands for Storage Area Network. This generally relates to one bank of storage for multiple servers and/or networks.
Now we will continue, bearing in mind that the units tested this month are not designed as replacements to traditional data backup tools such as tape, but are designed to allow your company to handle larger disk-based data storage facilities. So please don’t get slack and take the redundancy they offer for granted, or else it may backfire and bite you where it hurts. Before I forget, ensure that your company has a policy of checking to ensure that the tape backups being created are actually working, and you can restore from them should the need ever arise.
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