From: Matt Garman <matthew.garman@xxxxxxxxx>
> 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
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