[ale] no putting swap on ssd

[Ron Frazier]

PS to my prior reply.  In podcast 284, he goes into a good bit of detail 
about why SSD's need TRIMMING.

http://www.grc.com/securitynow.htm

Audio and transcripts are available.

Ron

On 02/08/2011 10:24 AM, Greg Freemyer wrote:
> 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
>
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>    

-- 

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Ron Frazier

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