db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Shreyans Jain <shreyans2...@gmail.com>
Subject Re: Write Cache - Data Corruption
Date Sun, 16 Jul 2017 14:42:16 GMT
Why would we need any kind of power backup if every thing is directly
written to disk, write cache being off. Only risk would be of losing last
transaction data.

On Jul 16, 2017 7:58 PM, "Rick Hillegas" <rick.hillegas@gmail.com> wrote:

> On 7/15/17 10:12 PM, Shreyans Jain wrote:
>
> If we have write cache off, do we need a ups or some other power backup ?
>
> I'm not an expert on ups's, but my understanding is that they provide
> other kinds of protective power conditioning which you would want in a
> production environment. See, for instance, https://en.wikipedia.org/wiki/
> Uninterruptible_power_supply.
>
> Hope this helps,
> -Rick
>
>
> On Sat, Jul 15, 2017 at 8:02 PM, Rick Hillegas <rick.hillegas@gmail.com>
> wrote:
>
>> On 7/14/17 6:21 PM, Shreyans Jain wrote:
>>
>>> If we have a ups and we properly shutdown the OS, will then we have to
>>> disable write cache for the hard-disk in order to prevent data corruption.
>>> Are there any chances left for the data to be corrupted by power failure
>>> with write cache on?
>>>
>>> Regards,
>>> Shreyans Jain
>>>
>>
>> That will reduce your risk. But operating systems can crash before
>> flushing the cache to disk.
>>
>>
>
>

Mime
View raw message