Am 03.05.2020 um 23:46 schrieb Caveman Al Toraboran:
so, in summary:
/------------------------------------------------\
| a 5-disk RAID10 is better than a 6-disk RAID10 |
| ONLY IF your data is WORTH LESS than 3,524.3 |
| bucks. |
\------------------------------------------------/
any thoughts? i'm a newbie. i wonder how
industry people think?
Don't forget that having more drives increases the odds of a failing
drive. If you have infinite drives at any given moment infinite drives
will fail. Anyway I wouldn't know how to calculate this.
Most people are limited by money and space. Even if this isn't your
problem you will always need an additional backup strategy. The hole
system can fail.
I run a system with 8 drives where two can fail and they can be hot
swoped. This is a closed source SAS which I really like except the part
being closed source. I don't even know what kind of raid is used.
The only person I know who is running a really huge raid ( I guess 2000+
drives) is comfortable with some spare drives. His raid did fail an can
fail. Data will be lost. Everything important has to be stored at a
secondary location. But they are using the raid to store data for some
days or weeks when a server is calculating stuff. If the raid fails they
have to restart the program for the calculation.
Facebook used to store data which is sometimes accessed on raids. Since
they use energy they stored data which is nearly never accessed on blue
ray disks. I don't know if they still do. Reading is very slow if a
mechanical arm first needs to fetch a specific blue ray out of hundreds
and put in a disk reader but it is very energy efficient.
