Altirium logo

Archive for June, 2009

Data migration – making a molehill out of a mountain

It is very easy to accrue data, and with large diverse systems it is very easy to accrue very large volumes of the stuff from a wide range of different places. The problem comes when you want to get the data from this massive archive and onto a new format of tape to be accessed via a new system.

The more complex the system the more pitfalls when attempting to migrate the data. Where data is being streamed from multiple sources a technique known as multiplexing is often preferred as this gives the best use of the bandwidth available for data backup. The problem comes with restoring as each data set is potentially spread across multiple tapes, and the restore process using the originating backup software might well require that each set be restored individually and so you can end up having to read each tape multiple times. This effectively means that if you have an archive of 1000 tapes, you have to read 5,000 or 10,000 tapes to restore everything.

Read the rest of this entry »

VN:F [1.9.22_1171]
Rating: 0.0/10 (0 votes cast)

Who says UNIX file undeletion is impossible?

The recovery of data files that have been deleted is not always a matter of competence, to a great extent success is governed by the file system in use and how busy the system has been since the deletion.

Windows NTFS, for example, marks a file as deleted but until the MFT entry is reused all of the file’s allocation information is still present. Other systems clear some or all of a file’s allocation information as soon as there is deletion, which is why the recovery of deleted files from heavily fragmented FAT file systems is such a nightmare.

Read the rest of this entry »

VN:F [1.9.22_1171]
Rating: 5.0/10 (1 vote cast)

What future has tape data storage?

With the volume of data being stored doubling every 18 months, and the possibility of increased regulation in the financial sector following the recent debacle possibly tightening all areas including data retention and data availability, how best to secure data for the long term?

In our data recovery business we are seeing an increase in hard drive recovery work from disk based backup systems. “We don’t use tape anymore” being the gist of many a statement on the subject of backup strategy, “disk based systems are so much more easy to use, and recovering the data is less arduous”. This much is true, disk based storage systems can be on-line permanently, de-duplication can be used to reduce the volume of extraneous data, and down time caused by accidental file deletion or local system failure can be kept to a minimum.

Read the rest of this entry »

VN:F [1.9.22_1171]
Rating: 0.0/10 (0 votes cast)