PC-3000 Support Blog

Ext4 (fourth extended filesystem) is a journaling file system for Linux, developed as a successor to ext3. Ext4 is very scalable: the maximum file system would consume one million 1-terabyte (TB) disks.

Ext4 replaces the traditional block mapping scheme used by ext2 and ext3 with so-called extents. An extent is a range of the contiguous physical blocks, improving the large file performance and reducing fragmentation. A single extent in ext4 can map up to 128 MiB of contiguous space with a 4 KiB block size. One inode can store up to four extents.  If there are more than four extents to a file, the rest of the extents get indexed in a tree.

These features of the Ext4 file system are very important for OS functionality, but useless for data recovery from RAID arrays.

In this tutorial, we will walk through the building of the RAID configuration using Ext4 metadata (features implemented in this file system). At first, we will apply automatic mode to search for the RAID metadata and build the configuration on-the-fly. After that, we will manually fill the RAID matrix and look into the features of Ext4.

We will use the power of Data Extractor RAID Edition to assemble information from the RAID on 4 disks. Although the functionality of Data Extractor RAID Edition is quite intuitive, in this guide we will do everything from scratch and explain every step we make.

This tutorial is probably not for those who are interested in making quick and high profits. But if you want to gain a deeper understanding of the file systems and how to build one from scratch, then you’re in the right place.

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Starting from 2017 ACE Lab began to produce the new revision of PC-3000 Express with some enhancements and new power supply adapter.

The main reason why the new ports have been added is that power supply blocks in today’s PCs either don’t use old 4-pin PATA Power anymore or they use only one branch with 2-3 connectors. Our engineers have decided to change it to the new POWER SATA ports for more convenient connection to power supply blocks in modern PC configurations.

Another thing that has been changed – is a new bridge chip 88SA8052-64 QFN Serial ATA 3.0 GB/s with improved power scheme. With a few hardware and software improvements, the speed and stability of SATA ports are increased.

What’s new about it? Of course, the first thing that will catch the eye is new POWER SATA ports for providing power supply to the PC-3000 Express.

But the main feature was a surprise for our customers who had bought the new revision of the PC-3000 Express! Please read further to learn about it.

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