How to choose the right data backup system for your business. Let\u2019s do an experiment: Turn off all your computers holding any accounting, sales, database, ordering, shipping or manufacturing information. Now go about your business.Wait \u2014 now you have no business.If you\u2019ve been reading this column for long, you know\u00a0data backup strategies abound. You can save data to tape, hard disk drives, hosted storage servers and burn it to CDs for individual systems. You can back up servers and clients to one system, or use one method to back up servers and another for clients. How do you choose?\u00a0First, by deciding a few things. Do you want to capture all information every backup cycle, or do a full backup some days and an incremental one on others? Do you want to back up each computer separately, or collect files from multiple PCs and back up just those files. We recommend the former. By grabbing all the information from individual desktops and laptops, it\u2019s easy to recover data files your users accidentally delete.Next, decide whether you want to use tape, hard disk or online storage systems. Tape remains the leader in low cost per megabyte of data stored and easy portability for offsite storage. Hard disks are faster, but require a method for storing the data offsite, such as online storage.\u00a0Backing up servers: If you have only one server holding all your business files (accounting, sales, etc), the least expensive option is to attach a tape system with enough capacity to grab the complete contents of your disk. Twenty gigabyte tape drives cost a few hundred dollars; an 80G-byte drive costs less than $1,000. Hard disk backup systems may cost less, but tape provides the critical offsite storage option.If you have several servers to backup, say a total 200G bytes of data, autoloader systems are dropping in price. Autoloaders hold multiple tape cartridges and mount them on the tape drive as needed, greatly expanding backup capacity. Gateway just announced new autoloaders, including a system that starts at $1,500 and can store 432G bytes in one backup session. Dell offers similar systems.\u00a0Sony \u00a0has desktop autoloaders incorporating the AIT-2 tape technology\u00a0we discussed last week. And Exabyte now has autoloader units for less than $3,500. Note, these prices are for hardware only, so expect to spend as much as an additional $1,000 on backup and recovery software and tapes.\u00a0Backing up individual computers: If your client PCs store data on the server automatically, or copy data to the server regularly, you\u2019re set \u2014 the server backups will grab the client data, too. If not, look for a system that backs up clients and servers. The RocketVault product\u00a0we tested a few weeks ago automatically pulls data from each computer (server and client) on the network, storing it both locally and remotely (for a fee). RocketVault is the first system combining local hard disk backup and online storage priced within small businesses\u2019 reach ($2,500 and up).You can take the backup unit to the PC, but you\u2019ll probably forget to back up when you\u2019re busy. Many new tape drives, like the Sony StorStation\u00a0we recently tested, have USB or FireWire connections. Using USB to plug a laptop into a tape unit will make life much easier when you replace the laptop after it\u2019s upgraded, broken or stolen. External hard disks offer the same option, but don\u2019t yet have the offsite storage capability of tape drives. However, hard disks tend to cost only a few hundred dollars for 80G bytes and back up faster than tape drives.