SSD support in Anaconda/F14

Camilo Mesias camilo at mesias.co.uk
Mon Dec 27 01:06:21 UTC 2010


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-erase-block-size/

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 at 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 at 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-state-drives-ssds-and-linux/9190

I changed the elevator to noop in /etc/rc.local and set noatime and
discard in /etc/fstab.

-Cam


More information about the devel mailing list