Why didn't I know it was a RAID system? Shouldn't it be disclosed?
There's an old saying in IT..... RTFM, and also in the case of dell, look at what you've spec'd on the website.
Umm, they don't do this without warning you about it. You make the choice when ordering.
Not only that, but it's a lesson learnt the hard way for the purchaser that when something turns up in a box, you take a couple of minutes to check the configuration is as expected and, in the case of RAID recreate the logical drive in the RAID format you require having spent a couple of minutes on Google looking at the pretty diagrams that show you exactly what the difference is between the different RAID types.
Furthermore, it's yet another lesson learnt the hard way that your need to
BACKUP AND CHECK YOUR BACKUPS ! This comes up time and time again here on PPRune..... backup backup backup backup, how many times do you lot need to be told !
The MINIMUM rule for backups is that at any one time you should have three copies of your data :
- Live (the one you are using, and yes, RAID is considered "Live", as its only one logical system)
- Nearline Backup (generally an online medium such as external hard drive ...so you could use something like Apple's Timemachine delta snapshotting.... or you could upload to a cloud service if you trust them with your data).
- Offline (i.e. tape or other medium that spends its life
disconnected from your machine unless being written to or read from for the purposes of backup/recovery). And no, "the cloud" or a NAS box sitting in a cupboard under the stairs do NOT count as offline. Tape is best, external unplugged hard drive is next, but if you insist on using USB sticks for this, use a minimum of two from different well known brand major manufacturers (copy the same data onto both sticks !!!).
Why is the third offlline disconnected element so important ? Because it gives you protection against live corruption of data, whether accidental or malicous (viruses etc). If you maintain a bunch of offline media of various vintages (or follow a rotation scheme such as GFS, Hanoi or other), it also gives you a greater chance at recovery from creeping corruption scenarios where you don't notice it until it's too late.
You then build upon the minimum above to meet your own requirements (e.g. offsite storage of offline media, rotation schemes in order to build additional redundancy and/or data retention requirements etc.).
RAID is not infallible... believe me, I've seen some pretty nasty data corruption scenarios !