Beginner raid question

[jonas82swe]

I have a beginner question about using software raid on Ubuntu and what the smartest way is to build the hardware for a home-file-server.

My plan is to have a server with one system disk(SSD 60GB) and 3-6 2TB disks in a software raid 5 or 6 or 10(haven’t decided yet...) using mdadm. So my idea is to not include the SSD drive in any raid, and just run it standalone with Ubuntu server.

Anyhow, let’s say that I create a raid5 with four disks. After a awhile the SSD crash(as I probably will do after a couple of years). What will then happen with my raid 5?

Will I be able to buy a new “system disk” and just install a fresh Ubuntu version + mdadm and then the system just recognize my old raid5 that was built on the old crashed Ubuntu? Or should I start to cry because my raid5 is gone? Maybe there are some checksum or similar(I don’t know software raid 5 works…) that are needed from the old crashed Ubuntu to recognize the raid5?

The reason to why I want to have separate system disk is because I want a fast disk for the system and separate the file storage on separate disks that are bigger(and slower) but cheaper ). Also, if not really really necessary I want to avoid using two SSD in a raid as system disk(disk are expensive).

I want to keep my system as simple as possible so I want to avoid the need to take system backup(like snapshots). The server is only for home use so I doesn’t matter if I have a downtime of a couple days, and installing Ubuntu again from the beginning is simple and not so time consuming. The most important is that I can connected the raid5 to the new freshly installed Ubuntu.

Many thanks in advance for your help!

[Cheesemill]

All of the RAID information is on the storage drives, you can do a new installation or even move the storage drives to a different machine and the RAID will work just fine.

One thing to point out is that RAID is not a backup solution, it's a continuity plan that only protects against drive failure.

You should always keep a proper backup of your data as well as using RAID.

[jonas82swe]

All of the RAID information is on the storage drives, you can do a new installation or even move the storage drives to a different machine and the RAID will work just fine.

One thing to point out is that RAID is not a backup solution, it's a continuity plan that only protects against drive failure.

You should always keep a proper backup of your data as well as using RAID.

Thank you very much for your reply.

A ha, I see, great news that the raid information is on the storage drives. Then my idea will work for my user case.

- I recently learned that when reading about different how-to about raid , the reason to why I want to use raid except for continuity is simply by practical and convenient reasons(to have a big storage location instead of spreading files on different HD).

Thanks again.