Re: Re: Desperate with 870 QVO and ZFS

From: <egoitz_at_ramattack.net>
Date: Wed, 06 Apr 2022 14:36:42 UTC
Hi Rainer! 

Thank you so much for your help :) :) 

Well I assume they are in a datacenter and should not be a power
outage.... 

About dataset size... yes... our ones are big... they can be 3-4 TB
easily each dataset..... 

We bought them, because as they are for mailboxes and mailboxes grow and
grow.... for having space for hosting them... 

We knew they had some speed issues, but those speed issues, we thought
(as Samsung explains in the QVO site) they started after exceeding the
speeding buffer this disks have. We though that meanwhile you didn't
exceed it's capacity (the capacity of the speeding buffer) no speed
problem arises. Perhaps we were wrong?. 

Best regards, 

El 2022-04-06 14:56, Rainer Duffner escribió:

>> Am 06.04.2022 um 13:15 schrieb egoitz@ramattack.net: 
>> I don't really know if, perhaps the QVO technology could be the guilty here.... because... they say are desktop computers disks... but later.
> 
> Yeah, they are. 
> 
> Most likely, they don't have some sort of super-cap. 
> 
> A power-failure might totally toast the filesystem. 
> 
> These disks are - IMO -  designed to accelerate read-operations. Their sustained write-performance is usually mediocre, at best. 
> 
> They might work well for small data-sets - because that is really written to some cache and the firmware just claims it's „written", but once the data-set becomes big enough, they are about as fast as a fast SATA-disk. 
> 
> https://www.tomshardware.com/reviews/samsung-970-evo-plus-ssd,5608.html