I'm confused now about what Anaconda has done. I checked with the
commands from this site:
http://thunk.org/tytso/blog/2009/02/20/aligning-filesystems-to-an-ssds-er...
And starting fdisk with different arguments gives more sensible
looking results. Note that I haven't changed the on-disk structures at
this point.
[root@newt ~]# fdisk -H 224 -S 56 /dev/sda
Command (m for help): p
Disk /dev/sda: 60.0 GB, 60022480896 bytes
224 heads, 56 sectors/track, 9345 cylinders, total 117231408 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e2854
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 117229567 58101760 8e Linux LVM
Since C/H/S are a fiction, does this mean that the layout chosen by
Anaconda is actually OK?
Also I ran a command against the PV:
[root@newt ~]# pvs /dev/sda2 -o+pe_start
PV VG Fmt Attr PSize PFree 1st PE
/dev/sda2 vg_newt lvm2 a- 55.41g 0 1.00m
This also seems to suggest the 1st PE is reasonably aligned.
Can anyone explain if I have misunderstood these commands?
Next I checked for other tweaks that might be of use and found:
http://www.zdnet.com/blog/perlow/geek-sheet-a-tweakers-guide-to-solid-sta...
I changed the elevator to noop in /etc/rc.local and set noatime and
discard in /etc/fstab.
-Cam