Contents
What does mdadm do for software RAID on Linux?
MDADM is a tool that allows to creation and management of software RAIDs on Linux. Before going into the steps for configuring we will check the prerequisites for the setup. Following are the prerequisites:
Is there a RAID 6 implementation in Linux?
Does anyone know if the RAID 6 mdadm implementation in Linux is one such implementation that can automatically detect and recover from single-bit data corruption. This pertains to CentOS / Red Hat 6 if those are different from other versions. I tried searching online but didn’t have much luck.
Which is the only standard RAID level other than Raid 2?
Wikipedia says “RAID 2 is the only standard RAID level, other than some implementations of RAID 6, which can automatically recover accurate data from single-bit corruption in data.” Does anyone know if the RAID 6 mdadm implementation in Linux is one such implementation that can automatically detect and recover from single-bit data corruption.
How to get mdadm to re-find my array?
Using disk utility, I could see that the drives are /dev/sda and /dev/sdb so I tried running sudo mdadm -A /dev/sda /dev/sdb Unfortunately I keep getting an error message stating mdadm: device /dev/sda exists but is not an md array Drives: 2 x 3TB WD Red (same models brand new) OS installed on third drive (64GB ssd) (many linux installs)
What happens in the checkarray function in mdadm?
The README states that in times of failure the checkarray reads as follows : If, however, while reading, a read error occurs, the check will trigger the normal response to read errors which is to generate the ‘correct’ data and try to write that out – so it is possible that a ‘check’ will trigger a write.
How to mark a RAID device as faulty?
Example 2: Marking a RAID device as faulty and removing it from the array This is a mandatory step before logically removing the device from the array, and later physically pulling it out from the machine – in that order (if you miss one of these steps you may end up causing actual damage to the device):
What does rebuildfinished event detected on mdadm mean?
May 9 15:35:35 wc2 mdadm [1508]: RebuildFinished event detected on md device /dev/md/3, component device mismatches found: 128 (on raid level 1) Note: the ATA error UNC means Uncorrectable error (often due to bad sectors on the disk). A simple script can be used to monitor the mismatch_cnt with Icinga/Nagios.