There are 4 hosts combined in vsan and RAID on each host?

Question

System administration

There are 4 hosts united in a vsan cluster, does it make sense to configure RAID 5 on each server?
or all the same there is vsan How to be?

Answer 1

At a minimum, RAID-5 in production can lead to very funny consequences, when some other disk crashes during the rebuild and everything gets up.
The decision to do something should be made on the basis of a comprehensive analysis of the system, the tasks and requirements. No conclusions can be drawn from your two lines (except that you want to do a potentially dangerous thing).

Answer 2

In principle, the fifth raid is not needed, even on home torrent storages - this is an extremely flawed type of array, very much shifted towards cheapness (although the gain there, in fact, is not so big) at the cost of reliability and performance at the most inopportune moment.

Answer 3

In a good way, there is no need to configure an additional RAID level at the host level, it is enough to correctly configure the redundancy of distributed data storage in the vSAN itself with the reliability required by the terms of reference, and then run perf tests in order to find out the load limit that this vSAN will pull, since it depends on the reliability method.

Answer 4

Raid5 is an outdated solution.
It made sense in the days when SATA didn't exist yet, IDE was terrible in speed, and fast options for databases were for example Fiber Channel or SCSI at 36 GB 10k rpm, which cost several hundred bucks apiece - then raid 5 was quite even useful and saved a lot of money.
For when the raid is running, everything is decently fast, and if one disk has fallen out, then often the linear speed is not as critical as IO, which do not fall much. In addition, with the small size of a single disk, the rebuild did not take up too much.
Raid5 doesn't really make much sense right now, since the disks aren't that expensive to get to ten if needed.