[ale] no putting swap on ssd

[Greg Freemyer]

On Tue, Feb 8, 2011 at 4:23 AM, Ron Frazier
<snip>
> I also, a few times a year, SpinRite my hard drives and refresh the data
> in every single sector with read invert write read invert write cycles.
> Keeps 'em purring like a kitten.  We had a long discussion about that
> recently on the list.
>

Ron,

Does spinrite also have a SDD refresh feature?  The issue I mentioned
about static data being held out of the wear-leveling process would be
overcome if all active data on the drive were read and re-written
every so often.

ie. When you write a EB the current lightly used EB should be moved to
the free area and one of the most heavily used should be pulled and
put into that static slot.  Then a few months later you can do it
again.

Thus a SSD refresh would be a very nice addition.

Trouble is because of trim, you really only want to read/write EBs
that are allocated.  And the ATA-8 spec. doesn't provide a way to
tell.

(eg. reading / writing a unallocated EB will turn it into a allocated
EB.  That's fine for real data, but very bad to just do across the
entire SSD.)

Thus you have to parse the filesystem and figure out which blocks have
live data and which don't.

I think the e2fsprogs package has some userspace tools that could help
with that, but I don't know.  (That package supports ext2/ext3/ext4.
For xfs, use xfsprogs.  Not sure about other filesystems.)

If spinrite had a tool for that, it would be really nice.

Greg