TAPE BACKUP

IBM 704 tape systemBack at the dawn of computers in the early 1950s there has been a need for a backup. IBM came up with their 7 track 1/2 inch in 1952. The image shows the IBM 705 tape system with several drives along the wall.

Over time the mainframe system used a range of tape products. The advantage of tape is that it can be stored for long periods of time, however NASA has reported some archives suffered from a 75% failure rate.

In the early days of the personal computer tape backup products were available in 3½” (QIC-40) and 5¼” (QIC-525) formats among others. These tapes were designed from the quarter inch compatible (QIC) standard.

The DC2000 tape drives used the floppy drive controller which limited their bandwidth rather severely and could take many hours to copy 40MB of data.

The old Archive Viper 525 tape drive we used had enough capacity (525MB) to hold the entire DOS file system on a single tape. FAT32 however had more room which allowed the tape to filled in one session instead of multiple sessions which was common in the DOS period.

Tape improved over time but the price kept it away from the mainstream. 4mm and 8mm tape products improved capacity and eventually the 1/2 inch tapes evolved into the GB and TB capacity range. Linear Tape Open (LTO) is now the dominant tape format, rival efforts have all failed as the industry now has settled towards the open standard. Tape drives continue to be very expensive but tapes have experienced tremendous pressure from hard disks which keeps the prices low.

We have an old Adaptec PCI AVA-2906 SCSI and SCSI-2 controller that works with even the most recent versions of Windows.The old card uses the 50-pin cable which could support 7 devices which was helpful compared to early hard disk controllers. With several competing storage solutions, the SCSI card allowed them all to be consolidated to some extent.

Modern machines however are starting to abandon the PCI slot which will eventually obsolete the old cards. SCSI has evolved over time and various cards can be operated side by side as needed.LTO tape are the last of the tape systems and they needs the more recent LVD type which is available for PCI Express which eliminates obsolescence to some extent. LTO tapes are slightly more expensive than high capacity hard disks.

eBay has lots of controller cards for most tape drives. Data recovery is usually not too difficult as drives are mature. SCSI-320 is used by tape drives which are low cost.

Modern SAS controllers are needed for recent tape drives. Controllers are easily available for PCI Express x8 slots. LTO-7 needs SAS 6 Gbps which is not very demanding by modern standards which means a controller card can handle 4 drives easily. Enterprise rack based solutions now reach 50PB or more.

SATADOCK525

The Startech SATADOCK525 which proves front panel slots for SATA hard disks enables the use of hard disks in the role previously held by tape. The SATADOCK525 is capable of 600MB/s with SATA-III ports which is faster than the SCSI ports used by tape. 2TB notebook disks are under $99. Desktop disks now reach 10TB.

Front panel slots make notebook disks a de facto “tape” and they are dramatically faster than the old tape drives. Notebook disks are smaller than tapes too. So storage is less of an issue. Using a RAID card it’s possible to use multiple slots for even more flexibility. Multiple slots allow for copying; no tape does that.

Low cost USB slots are wildly popular. They easily connect to internal USB 2.0 headers directly. The also feature flash card slots too.

USB molded cables for SATA are very low cost and they can be used with bare notebook disks for backups or file recovery.