If the partitions for a virtual disk are not properly aligned to the OCFS2 block size, OCFS2 serializes I/O to the virtual disk image resulting in degraded performance. This only affects virtual disk images stored on OCFS2 repositories and does not apply to NFS repositories.
Workaround: Check for misaligned partitions in the virtual disk images and, if any are found, recreate the disk images with properly aligned partitions. To determine whether partitions are correctly aligned, use fdisk -lu to find the starting sectors of the partitions. Ensure that these are a multiple of 8 (512 byte sectors), which aligns them at 4 KB, the OCFS2 block size.
Many recent operating systems often start the first partition in sector 2048, aligning it to 1 MB, which works well for most storage RAID stripe sizes.
Bug 14355588