RAID array hosting server - separate system or with a date?

Question

linux

Hey!

It is urgent to raise the server for hosting tasks, a couple of voluminous online stores will be spinning.
The disks are planned to be SATA, there are 6 places for hard disks.

A ride 1/10 is planned
Question - is it better to install the system with separate 2 disks for ride 1 or put the system into a common array and make all the disks like a ride 10?
How in this case with backups - a separate disk or an array?

SSD for cache is planned - though there is no experience at all in this :(

Answer 1

The most optimal single RAID-10

Answer 2

So, in principle, I thought, it’s just that they write somewhere that it doesn’t really make sense to put a separate array under the system in ride 10

Answer 3

RAID6

Answer 4

do not listen to idiotic topics about raid 6 and so on. this is generally insanity
, in fact, you have a choice of raid 1 and 10, and here you need to understand that,
as a rule, 90% of sites require this reading, if in your case you need 1 even if there are 10 disks in it. (you will get a 10-fold increase in reading) and with a large number of small files, this is critical.
now, by partitioning disks into the system and data
, everything is simpler here, the classic scheme is
gluing disks in 1 raid, each disk is divided into two
md1 md0
one of them is a system another site
We get reading acceleration for each of them, redundancy for each of them, in general, everything by feng shui.
why bad 10
Firstly, you need to understand that the multiplicity of the probability of collapse into it increases by 2 times compared to 1, and with an increase in the screws, it grows in the same proportion of 1 to every two screws.
But you get a 50% increase in RECORD speed,
in fact, this is not so necessary.
BUT if you have only 4 screws in raid 10, then the failure of 1 already leads you to the potential danger of losing all data, since 1 of the screws now has unique content, and if it makes a mistake even by a byte during synchronization, the raid will disintegrate completely. which is kind of creepy.
So it's better to have 4 screws in 1, then if 1 of the screws fails, you have 3 more reservations.
I also recommend paying attention to ssd, they give a very good increase.
I recommend adding hdd for backups.
5 3 6 raid is mathematical and requires strong CPU involvement.

Answer 5

Most controllers allow you to create a "boot" partition when you create an array. The system will see it as two separate disks. So do 10 + by means of the controller allocate a partition for the system.