ZFS melting under postgres...

[Travis Mikalson]

Ivan Voras wrote:
> Dag-Erling Smørgrav wrote:
>> Ivan Voras <ivoras at freebsd.org> writes:
>>> Maxim Sobolev wrote:
>>>> That's no longer true. You can't get more than 5-10MB/s from
>>>> seek-intensive RAID0 with two 15K drives, while 20-30MB/s is not a
>>>> problem for the comparable priced/sized SSD drive.
>>> Can you point me at a vendor with SSDs of such characteristics?
>> Kingston CF Elite, 20 / 25 MBps write / read
>> Kingston CF Ultimate, 40 / 45 MBps write / read
>>
>> SanDisk Extreme III CF, 20 MBps
>> SanDisk Extreme IV CF, 45 MBps
>>
>> Sony CF 300X, 45 MBps
>>
>> These are just a few of those available from my regular supplier.
> 
> These are all "normal" CompactFlash cards, for which the widely
> available size seems to be 16 GB max, right? I was thinking about
> something more like this:
> http://gizmodo.com/gadgets/peripherals/adatas-128gb-solid-state-drive-sees-the-light-of-day-231693.php
> or this: http://www.mtron.net/English/Product/pc_msd1000.asp
> 
> Did you (or anyone) deploy CF drives for production servers?

If you're using compact flash for something that's constantly updated 
like a ZIL, wouldn't your CF card die real quick?

I've deployed CF in production, but as a read-only medium with 
occasional writes only for configuration updates.

 From what I understand the specialized expensive solid-state drives 
that you guys are discussing are better designed for this type of write 
duty whereas CF would probably not last very long.

Since a ZIL is not really seek-intensive, why not just offload it to its 
own standard hard disk that has its write caching and all other similar 
data-corrupting technologies disabled?