[CentOS] home directory server performance issues

[John Doe]

From: Matt Garman <matthew.garman at gmail.com>
> I’m fairly certain I did not align the partitions optimally:
> Number  Start    End        Size        Type    File system  Flags
> 1      63s      465884s    465822s    primary  ext2        boot
> 2      465885s  134207009s  133741125s  primary              lvm
> Number  Start  End          Size        File system  Name  Flags
> 1      34s    5720768606s  5720768573s                    lvm
> Can anyone confirm that the partitions are not aligned correctly, as I
> suspect?  If this is true, is there any way to *quantify* the effects
> of partition mis-alignment on performance?  In other words, what kind
> of improvement could I expect if I rebuilt this server with the
> partitions aligned optimally?

They indeed do not look like aligned...
First, I am no expert but:
At one point , the minimum to do was to at least start on 64 instead of 63.
Now, if you add RAID stripes, 4k disks... it is more complicated.
https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/newstorage-iolimits.html

You can see the effects on non alignment by looking at such images:
http://www.ateamsystems.com/blog/FreeBSD-Partition-Alignment-RAID-SSD-4k-Drive

Formatting also takes alignment parameters.  By example, stride and stripe-width for ext...

JD