Data Recovery Weekly

A customer walks in and says: We need to recover a FATX volume, can you do that? - Sorry, no. Various exotic filesystems, btrfs, logfs, and even ReiserFs have always been considered a job for a data recovery serivce, not an automated software. Software is cheap, but only resolves common cases by applying typical solutions. Data recovery service is expensive, and applies its high fees toward the difficult cases, e.g. writing custom software to deal with just one specific case. Lately, there is an influx of requests for something nonstandard. The latest hit was - We have ReiserFs on the RAID5. - Okay, no problem. Turns out there was a problem. The RAID5 was using 512 bytes per block. JMB 393 controller. Oops. So far we have delayed parity (from HP SmartArray), Promise RAID 6 with its non-standard Reed-Solomon, Promise 1E interleaved layout, exFAT filesystem recovery . The capability to recover RAID with a block size of 512 bytes is in the pipeline, currently undergoing testi...

If you want some unusual RAID layouts, call Promise. So far, Promise controller has the most bizzare RAID 6 variation we've seen, and also gave us a nasty surprise with RAID 1E. Typically, RAID 1E would be laid out as follows 1 1 2 2 3 3 4 4 5 5 6 6 (the above is so-called NEAR layout) or 1 2 3 4 5 6 7 8 9 3 1 2 6 4 5 9 7 8 (the above is FAR layout). Now Promise combines the best of both worlds to produce a third variation (Promise 1E layout) 1 2 3 3 1 2 4 5 6 6 4 5 Looks promising , doesn't it? So, the implementation of RAID 1E recovery capability in ReclaiMe Free RAID Recovery ( www.FreeRaidRecovery.com ) is delayed until we figure out how to handle this one.

Promise RAID6 array, 4x WD EARS (Green) drives, NTFS-formatted. Copying files to the array maxes out at 2 MB/sec. Quite painful as we already lost about a week trying to create a meaningful test sample. For reference, controller is Promise SuperTrak EX4650, flashed to the latest firmware.