Category Archives: RAID

How to replace an LSI raid disk with MegaCli

The MegaCli64 command has a lot of command line switches and the syntax is also cryptic. If you have identified a failed, or failing disk, it is possible to replace it using the MegaCli utility. The following commands I found useful when trying to physically identify a failed disk and replace it. IMPORTANT NOTE: Make sure the array is … Continue reading How to replace an LSI raid disk with MegaCli

MDADM Cheat Sheet

Create a new RAID array Create (mdadm –create) is used to create a new array: [codesyntax lang=”bash”] mdadm –create –verbose /dev/md0 –level=1 –raid-devices=2 /dev/sda1 /dev/sdb2 [/codesyntax] or using the compact notation: [codesyntax lang=”bash”] mdadm -Cv /dev/md0 -l1 -n2 /dev/sd[ab]1 [/codesyntax] /etc/mdadm.conf /etc/mdadm.conf or /etc/mdadm/mdadm.conf (on debian) is the main configuration file for mdadm. After we … Continue reading MDADM Cheat Sheet

Create bitmaps for RAID device

It’s a good idea to create bitmaps for RAID device that are stored internally (storing bitmap files on other filesystems may result in serious problems). Bitmaps slightly impact throughput but significantly reduce the rebuilt time when the array fails. [codesyntax lang=”bash”] mdadm –grow /dev/mdX -b internal [/codesyntax]

How to migrate a single disk Linux System to software RAID1

This guide explains how to set up software RAID1 on an already running Linux (Ubuntu 12.10) system. The GRUB2 bootloader will be configured in such a way that the system will still be able to boot if one of the hard drives fails (no matter which one). Preliminary Note In this tutorial I am using … Continue reading How to migrate a single disk Linux System to software RAID1