Disks can experience temporary failures that cause them to drop out of the array but can be corrected by a system reboot or controller reset. This might really be a one-off error but I would follow up with smartctl or a vendor utility to confirm that the disk isn’t on the point of permanently failing. … Read more
The terminology you are looking for is a “RAID level migration”. According to this, it’s possible. I haven’t done it, but the procedure looks like you should add the new drive as a hotspare to the existing array, then use mdadm to update the raid level and the number of raid devices.. You’ll need a … Read more
Besides whatever metadata the RAID controller uses, are there any differences between these two arrays (in terms of data layout, performance, reliability)? Yes. RAID5 uses a single, rotating parity while RAID6 uses two. You may be visualizing dedicated parity disks, but they’re in fact rotating. RAID5 should be rather straight-forward: With RAID6, imagine the last … Read more
Linux software RAID is not going to protect you from bit corruption and silent data corruption is a well known issue with it. In fact, if the kernel is able to read the data from one disk it would never know that it is bad. The RAID only kicks in if there is an I/O … Read more
Generally I’d say RAID 1+0 will tend to be more widely used than 1+5 or 1+6 because RAID 1+0 is reliable enough and provides marginally better performance and more usable storage. I think most people would take the failure of a full RAID 1 pair within the RAID 1+0 group as a pretty incredibly rare … Read more
You have disadvantages and advantages with each approach; it depends on why you’re using RAID. Most people use it for availability. They don’t want a drive to die and end up having to take their system or server down. In that, you don’t use RAID 5. I learned it the hard way and hammer this … Read more
The primary (historical) reasons for partitioning are: to separate the operating system from your user and application data. Until the release of RHEL 7 there was no supported upgrade path and a major version upgrade would require a re-install and then having for instance /home and other (application) data on separate partitions (or LVM volumes) … Read more