Improving performance of the disk subsystem is the most topical issue today. This is caused by the low cost of HDD that takes a leading position in the mass segment. More than a half of the resource-intensive applications have a "vulnerable spot" that are the spindle drives. In this case, everything does not depend on the bandwidth of SATA interface, but it depends on the physical capabilities of the mechanical components of the magnetic disk. The bandwidth of SATA-II and SATA-III interfaces makes 300MB/s and 600MB/s respectively, and the maximum performance that can provide a regular HDD does not exceed 150MB/s. Therefore, the transition to SATA-III-interface will be reasonable only for SSD, but it is not suitable for everyone.
In order to evaluate and to test the effectiveness of different types of disk subsystems were chosen following solutions:
1. OCZ RevoDrive X2 PCI-E SSD 100Gb
2. Plextor PX-128M2S SSD 128Gb
A few days ago, one of the hard drives went down on the budget’s array of 16x1Tb drives. The array level: RAID 6. The situation got complicated by the fact that (as it turned out) previously had stood a cooler on the video card of the same server that was not previously noticed, and after HDD was replaced due to changes in cooling mode of the casing, and this became appear in the form of hanging during synchronization, which itself is very unpleasant. It turned out that an array stopped auto-building, and a few drives were marked as faulty, so I had to deal with it seriously, checking out with the wiki, manuals and forums (forums are the most useful, as they describe the experience of specific people in specific situations).
The structure of array:
md0 - / root 8x1 Gb, RAID 6
md1 - / data: 16x999 Gb, RAID 6