On 13/03/2015 15:47, Scott Marlowe wrote:
> On Fri, Mar 13, 2015 at 7:16 AM, Achilleas Mantzios
> <achill@matrix.gatewaynet.com> wrote:
>> On 13/03/2015 13:40, Joshua D. Drake wrote:
>>> On 03/13/2015 04:27 AM, Achilleas Mantzios wrote:
>>>>
>>>> Hello,
>>>>
>>>> we maintain a DB of nearly 500GB of data (and always getting larger),
>>>> and we are currently thinking of moving to SSD.
>>>> I have read Greg Smith's book on PostgreSQL 9.0 High Performance and his
>>>> considerations on SSD and the way that write back works.
>>>>
>>>> This particular model (Samsung SSD 850 PRO 1T) does not employ any
>>>> special circuitry, battery or capacitor
>>>> to enforce that the data are really flushed to the medium.
>>>>
>>>> What is your take on this? Is it dangerous to have PgSQL on this disk
>>>> especially in cases of power outages? (we have full UPS support, however
>>>> nothing can be overlooked, anything can happen)
>>>
>>> If it does not have power loss protection, don't use it.
>>
>> Thanx Joshua.
>>
>> If theoretically somehow we eliminate the power loss factor, would it make
>> sense to use such a disk?
> Sadly there's no way to eliminate power loss in real life.
>
> Now if you can live with some data loss corruption that's a different matter.
Thanx,
the question is if postgresql will recover, we can tolerate some data loss,
but no total db corruption, equivalent to fsync=false, with the db unable to recover.
>
>
--
Achilleas Mantzios
Head of IT DEV
IT DEPT
Dynacom Tankers Mgmt