What storage configurations to choose for different tasks?

Question

RAID

Good afternoon!
Tell me what storage configurations (data storage system) are used for different tasks?
1. Storage for file storage:
- what interface to connect to servers to choose iSCSI, FC, SAS?
- Which HDDs are better for SAS/SATA, 7.2/10/15K or SSD?
- in what RAID to collect? or use multiple different arrays?
2. Storage for DBMS
- the same questions as in paragraph 1
3. Storage for backup -
the same questions as in paragraph 1
4. Storage for use in virtualization
- the same questions as in paragraph 1
Well, the more justifications there are, the easier it will be for me to figure it out))

Answer 1

Answers to these questions imho do not exist without a planned load profile.
PS
Please unlearn the use of Russian abbreviations.
Everyone knows what san and nas are. SHD personally I had to google.

Answer 2

Without loads of advice will be a finger in the sky. For the same file washer, there can be both the cheapest solution on SATA 5400 and an option from the SSD raid.
Under a DBMS, personally from my practice, solutions have shown themselves well when combining several SAS15K and SSD as a hardware cache, but again, under a certain type of load (80%R / 20%W) innodb file per table, heavy queries, for another case there will be others options. Under a hot backup of the base, similarly (RAID 1, 10, 50, 60 are common, LUNs have their own specifics), under a cold backup they put the cheapest that they find within the required reliability, i.e. either SAS 10K or SATA 5400, usually in raid 10 or 50 (if we use a classic raid and not LUNs). In virtualization on small containers, SSDs perform well, or in the variant of medium and large containers, a hybrid like for a DBMS. Give a specific case - it will be possible to discuss.

Answer 3

@love4you , the solutions that I personally have seen are different, and not all of them are successful. Depends on the money allocated to the engineer, or on the equipment that he had. Everything will work in different variations. Storage for a garbage dump - again, what are the access requirements - it can be anything, but I would choose FC / SAS 10-15k for a large and loaded garbage dump, and SATA is normal for a small one. For a backup, you need requirements for reliability and recovery time. It is most reliable to store on tape libraries, by the way. For Wirth, you can use flasharray. But it all depends on TK and money. Something like this.
Look for articles where different configs are compared in terms of performance (there are also usually recommended which ones are for the trash and which ones are for Wirth).