Tape Drive Cartridge Recovery

Reasons for needing Recovery

Tape data storage can be inaccessible for a number of reasons:

• Tape drive failure has corrupted tape headers
• Tape media stretched or snapped
• Fire & water damage
• Media surface contamination and damage
• Accidental reformatting or erasure of tape
• Accidental overwriting of headers
• Tape backup software corruption
• Vibration damage
• Data residing after and EOF mark (overwritten)
• Errors residing mid file

Hardware Problems can also cause problems

• damaged motors
• Power supply failure
• Dirty equipment or environment
• Controller malfunction or failure

Formats that can be recovered by Nortek

• 4mm
• 8mm (including Exabyte), Super DLT & DLT tapes
• DAT, DDS, DDS2, DDS3, DDS4
• Seagate AIT, On-Stream, ADR
• QIC mini cartridge tapes
• 1/4" Cartridge
• LTO1 and 2

There are two primary types of recoveries on tapes:

Physical Damage:

This type of recovery may include dealing with issues such as deteriorating magnetic coatings, cracked or broken reels/cartridge shells, creased tape edges, twisted or folded tape, stretched or broken tape, etc. Recovery of damaged tape media often involves cleaning, splicing & re-spooling of good/new segments of tape into new carriers. Customized hardware and software tools are used to create a raw image from whatever portions of tape that is readable.

Logical Damage:

This type of recovery may be caused by tapes that were written with misaligned heads, and tapes that contain critical data and were re-initialized by mistake.

Logical recovery uses the raw image by examining the low-level data sectors and determining what fixes to tape format structures are needed to get access to the important data. Sometimes the existing structures are missing or damaged so much that data has to be extracted directly from the raw image.

Nortek programmers have created software tools to analyze, fix & recover data from raw tape images.

Starting with a telephone consultation on our free phone number, you will be provided with the help and expertise you need in order to put your data back into a more productive environment.

Nortek is geared to recover your data as fast and as always NO DATA - NO CHARGE. Because of the wide variety of tape media formats and backup applications the normal lead-time on a tape cartridge recovery project is 2 to 3 days at which time one of our engineers will contact you with the results of this evaluation. Normally the complete recovery time will vary anywhere for 2 to 10 days.

As mentioned, no two data recovery scenarios are identical in all respects. Therefore, this uniqueness makes it impossible to give a realistic indication of pricing without knowing all the facts for a particular case. Generally speaking a tape recovery job price starts at about $1500.00.

Examples of Tape Recording Methodologies

DLT

Descended from the DEC TK range of drives, the DLT has emerged as one of the major players at the high data capacity and high performance end of the market. It is arguably the most reliable format in todays market.

Serpentine Recording Format

DLT utilizes a recording style known as serpentine. Recording takes place as a sequence of track pairs running alternately from beginning of tape to end of tape and then back again:

This method of recording allows high speed operation and search. To locate a particular section of data on tape the drive can step across tracks until it is close and then search along the tape.

Overwrite

DLT is a very reliable tape. The majority of the problems that we see are the result of human error. Accidentally re-initializing a tape, or forgetting to enable the append option before starting a backup are common problems.

Media Failure

An error caused by a recording flaw might affect more than one data track and so an error might occur each time the drive passes that point on the tape. If the problem is the result of physical damage then you could be putting your data at further risk by attempting to read as the tape could break.

Reference Track Damage

If the reference track at the beginning of the tape is damaged then the drive will not be able to identify the recording and you will not be able to restore from your backup.

DAT

Derived from the SONY Audio DAT recorder and a joint HP/SONY recording format, DDS, DAT has rapidly become the most popular medium for tape backup.

Companies such as Hewlett-Packard have put great effort into the development of the 4mm DAT drive and are continuing to do so. Format is high capacity with good performance combined with drives and tapes which are of relatively low-cost.

The recording method used is helical scan. Data tracks are recorded diagonally across the width of the tape:

Overwrite

The data that has been overwritten is lost, but all older data from further along the tape will be recovered.

Media Failure

We can move past any damage and recover the data that we find. The recording is made in one direction only and so the damage is never re-visited.

Tracking

Nortek’s knowledge gained from the repair of all type of tape drive hardware allows us to rapidly make hardware adjustment for tracking problems with tapes.

Damaged System Area

If the system areas at the beginning of a tape are damaged then the tape will appear to be blank. Your data will still be there- Nortek can recover it.

Exabyte

Derived from the Sony Camcorder mechanism, but with improved data integrity, Exabyte’s 8mm backup device became prominent in the 1980s as a high capacity backup device for DEC VAX systems. Exabyte have continued to enhance the mechanism and improve the recording technique as the drive became popular for high-end networks and UNIX systems. The latest drive, the Mammoth, is capable of recording up to 40 gigabytes of data at extremely high speed.

The recording method used is helical scan. Data tracks are recorded diagonally across the width of the tape:

Overwrite

The data that has been over-written is lost, but all older data from further along the tape will be recovered.

Media Failure

We can move past any damage and recover the data that we find. The recording is made in one direction only and so the damage is never re-visited.

Tracking

Nortek’s knowledge gained from the repair of all type of tape drive hardware allows us to rapidly make hardware adjustment for tracking problems with tapes.

System Area Damage

If the system areas at the beginning of a tape are damaged then the tape will appear to be blank. Your data will still be there - Nortek will recover it.

Quarter Inch Cartridge

Quarter inch cartridge is a well established recording medium which predominated in the UNIX/PC environment prior to the advent of 4mm DAT. It also found favour with IBM as a main backup option for the first AS/400 mid-range systems.

The only current manufacturer of these drives is Tandberg Data. There are still many drives in use from other manufacturers such as Archive, Wangtek and Sankyo.

The recording method used is serpentine. Data tracks are recorded alternately forwards and then in reverse:

Overwrite

We can recover all data that has not actually been overwritten. The complication with QIC is that a full-width erase bar is energized during the recording of the first track. This is to ensure that the drive is writing to blank tape and thus avoid any problems with earlier data. It does mean that once a whole track has been written, the remainder of the tape has been erased.

Media Flaw

Data can be recovered beyond a media flaw, even though your backup software refuses to read any further. If the problem is restricted to the current track then the remainder of the data will be recovered intact.

Tracking

Nortek's knowledge gained from the repair of all type of tape drive hardware allows us to rapidly make hardware adjustment for tracking problems with tapes.