Volume (partition) alignment
Acronis Backup & Recovery 11.5 automatically eliminates volume misalignment – a situation, when volume clusters are not aligned with disk sectors. The misalignment occurs when recovering volumes created with the Cylinder/Head/Sector (CHS) addressing scheme to a hard disk drive (HDD) or solid-state drive (SSD) drive that has a 4-KB sector size. The CHS addressing scheme is used, for example, in all Windows operating systems earlier than Windows Vista.
If volumes are misaligned, the cluster overlaps more physical sectors than it would have occupied if aligned. As a result, more physical sectors need to be erased and rewritten each time the data changes. The redundant read/write operations noticeably slow down the disk speed and overall system performance. SSD drive misalignment decreases not only system performance, but drive lifetime. Since SSD memory cells are designed for a certain amount of read/write operations, redundant read/write operations lead to early degradation of the SSD drive.
When recovering dynamic volumes and logical volumes created in Linux with Logical Volume Manager (LVM), the appropriate alignment is set up automatically.
When recovering basic MBR and GPT volumes, you can select the alignment method manually if the automatic alignment does not satisfy you for some reason. The following options are available:
Select automatically – (Default) recommended. The software will automatically set the appropriate alignment based on the source and target disk/volume properties.
Use the following options only if you absolutely need to.
CHS (63 sectors) – select this option if the recovered volume will be used under Microsoft Windows XP and Windows Server 2003 (or earlier) on disks having 512 bytes per physical sector.
VMware VMFS (64 KB) – select this option when recovering the volume as a VMware Virtual Machine File System partition.
Vista alignment (1 MB) – select this option if the recovered volume will be used under Windows operating systems starting with Windows Vista, or when recovering volumes to an HDD or SSD drive that has a 4-KB sector size.
Custom – Specify the volume alignment manually. It is recommended that the value be a multiple of the physical sector size.
