I'm setting up a system with a system with a mdadm RAID5 which is the sole PV for a VG which hosts 4 LVs.
When I make the filesystem, would the
-E option be useful? Or is its effect not possible to know because of LVM shenanigans?
-E extended-options Set extended options for the filesystem. Extended options are comma separated, and may take an argument using the equals ('=') sign. The -E option used to be -R in earlier versions of mke2fs. The -R option is still accepted for backwards compatibility. The following extended options are supported: stride=stride-size Configure the filesystem for a RAID array with stride-size filesystem blocks. This is the number of blocks read or written to disk before moving to the next disk, which is sometimes referred to as the chunk size. This mostly affects placement of filesystem metadata like bitmaps at mke2fs time to avoid placing them on a single disk, which can hurt performance. It may also be used by the block allocator. stripe-width=stripe-width Configure the filesystem for a RAID array with stripe-width filesystem blocks per stripe. This is typically stride-size * N, where N is the number of data-bearing disks in the RAID (e.g. for RAID 5 there is one parity disk, so N will be the number of disks in the array minus 1). This allows the block allocator to prevent read-modify-write of the parity in a RAID stripe if possible when the data is written.