[CentOS] SSD for boot drive and OS

Sun Apr 15 15:59:32 UTC 2012
Les Mikesell <lesmikesell at gmail.com>

On Sat, Apr 14, 2012 at 11:39 AM, Frank Cox <theatre at melvilletheatre.com> wrote:
>> There is a significant mortality rate with consumer grade SSDs. If you
>> are going to use one, pair it up in a software RAID1 with some matching
>> partitions on the hard drive and then adjust the RAID to read
>> preferentially from the SSD. See
>> http://superuser.com/questions/293144/combining-ssd-and-hard-disk-in-software-raid1
>> for some links explaining how to do that.
> I'm just thinking... I wonder if it would be possible to somehow replicate the
> OS on both the SSD and the hard drive, such that you could just change the boot
> device in the bios to point to one or the other.  Which wouldn't exactly be a
> raid (with the overhead that entails) but just a change of boot device as
> required.

I don't know if there have been any real tests, but I'd expect that
for most real-world use you would get much better performance if you
spent the same money on additional RAM instead, since the OS will
automatically use it for disk cache.   There might be exceptions for
specific applications where you could tune the SSD to hold things the
application needs but that might otherwise be evicted from cache.

   Les Mikesell
    lesmikesell at gmail.com