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DLT tape recovery - can data be recovered after an overwrite?
Posted by Mark on Nov 21, 2008
Interesting data recovery job this one, most especially as it had been sent to three other companies in continental Europe before it found its way across the moat to dear old blighty.
The data on this tape was an Amanda backup from a Sun UNIX system, in the region of 80GB had been written to an SDLTII data cartridge for safekeeping, but no-one had set the tape to write protect. Consequently, when one of the IT staff went to recover some data from the tape, something went wrong and the DLT was re-initialised. From being a vital system backup brimming with data ready to be accessed, the DLT was just another scratch tape waiting to be used. Needless to say the accounts department who needed the data were non-too happy when their data could no longer be restore.
Cloud Cuckoo Land?
Posted by Mark on Nov 18, 2008
So, the people who brought us Vista have “unveiled” Azure so that now our data and applications can live somewhere else, in this place named “The Cloud”.
Rather than seeing this as a retrograde step, a reverse back to the time-sharing mainframes of the 1970’s and 1980’s, where access to a computer was often via renting a portion of someone else’s, this does seem to be a possible answer to the problems of data storage, application management, and data access, and one that takes away much of the headache of managing ones own infrastructure for the purpose.
But, who guards the guards?
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Throw the tapes away - disk backup is here
Posted by Mark on Oct 29, 2008
Data backup can be a nightmare, balancing the demands for instant access against the equally important need for security and reliance. Essentially there are Business Continuity demands that are competing with the requirement to be able to perform a Disaster Recovery.
The same people that patted you on the back because they could get their files back quickly from an online storage system might be the first in the queue to stick a metaphorical knife between your shoulder blades when the disk based backup system is off with the data recovery company, and you don’t have a good old fashioned solid and reliable tape backup.
So are tape backup systems better than disk based virtualized backup systems, do on-line backup systems trump all others? What is best?
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Who Said Tape Was Not Reliable?
Posted by Mark on Oct 23, 2008
Another tape recovery story, but one that shows an impressive level of resilience on the part of an old tape technology. The tape in question was a TK50, leading edge back sometime in the 1980s (and notably the technology from which DLT was developed) and after 20 years of being used each day as the boot media for a manufacturing system it had finally given up and a data recovery was needed.
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Catch-22, or “don’t keep the only copy of the software on the tape”
Posted by Mark on Oct 20, 2008
Ever had one of those days where having tried to do everything correctly that nasty stomach churning feeling becomes overwhelming as you realise that there is a major problem and a simple restore could now be a major tape data recovery issue.
You have the backup tape, you have the tape drives, but the only copy of the backup software is within a backup set on the tape and this backup is from 14 years ago and the software is not sold any more.
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Solid state media - a tough nut to crack?
Posted by Mark on Oct 19, 2008
USB pens are part of everyday life. Small and portable with a high capacity, most of us can get most of our important data onto one, they are trusted, sometimes even as a backup. They have no moving parts, so they cannot crash like a hard disk, so they must be pretty robust, right? I’ll never need a data recovery from one will I?
Wrong!
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The long and winding DLT
Posted by Mark on Oct 18, 2008
Tape is tough, but really …
As a data recovery engineer pretty well nothing comes as a surprise. We have received DLT cartridges where the tape has snapped, been overwritten, even where it has been submerged in flood water for over a week.
Nothing, though, has been quite as bizarre as the empty DLT case that arrived, along with a supermarket carrier bag crammed full of unwound tape. What was going on?
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RAID away
Posted by Mark on Oct 16, 2008
Interesting day for RAID recovery work, though emotions were divided with one happy customer and one greatly saddened one.
Like the old London bus joke about “none for ages then three come at once” RAID data recovery is not an everyday requirement but two turned up this morning within ½ and hour of one another. Both were 12 disk DELL units, one reported that 3 drives had failed, the other that two were offline.
Could we recover the data?
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Another one bites the dust
Posted by Mark on Oct 10, 2008
So it looks as though Fujitsu are about to handover their hard disk reins to Western Digital, or so the rumours abound. With IBM out of the picture, Maxtor having gone the say of Seagate how long before we are left with only one supplier for disk storage? Wonder who that will be.
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The Tale of the Tape
Posted by Mark on Sep 24, 2008
Well really the title should read, “The tale’s on the tape”
Computer forensic investigation stories tend to focus upon what has been found on so-and-so’s hard disk drive how, despite attempts to eradicate the incriminating data, the dastardly plot was foiled and we can all get back to the Malt bar and eat Scooby Snacks. But where else, other than the local hard drive, can the information you’re looking for be found.
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