Is it necessary to have the partitions that makeup a software RAID 1 array be aligned?
This guide states
"Software RAID: Although one needs to pay attention to correct alignment here as well, this is not explicitly necessary as at least 64 KB-sized blocks are used."
I don't understand how Soft RAID changes the performance hit / write amplification issue given the underlying SSD controller is still staggering file system pages across more than necessary flash pages.
Here is one of my drives, I believe that the partition starting at LBA 63, means I'm not aligned. Partitions were created via CentOS 5 installer.
Disk /dev/sda: 120.0 GB, 120034123776 bytes 255 heads, 63 sectors/track, 14593 cylinders, total 234441648 sectors Units = sectors of 1 * 512 = 512 bytes Device Boot Start End Blocks Id System /dev/sda1 * 63 610469 305203+ fd Linux raid autodetect /dev/sda2 610470 16996769 8193150 fd Linux raid autodetect /dev/sda3 16996770 25189919 4096575 fd Linux raid autodetect /dev/sda4 25189920 234436544 104623312+ 5 Extended /dev/sda5 25189983 234436544 104623281 fd Linux raid autodetect
Thank you so much!