Failed RAID5 disk array, questions about mdadm and recovery
location: linuxquestions.com - date: October 11, 2009
My server is running openSUSE 11.1 and I built a RAID5 array using Yast and three identical Samsung 1TB disks that mount as /dev/sdb1 /dev/sdc1 and /dev/sdd1. Everything ran fine for a couple of months then suddenly, for no apparent reason, the computer failed to start. It boots from another disk /dev/sda1 but tries to mount the raid array /dev/md0 and as this fails the boot stops at a rescue prompt. Not good. I removed /dev/md0 from fstab and the PC now at least boots to the GUI so repairing might be easier.
After a bit of fiddling about and trying solutions mentioned in other threads it seems my problem is slightly different, hence the new thread. What seems slightly contradictory is that all my three disks appear clean:
mdadm command to restart double failed raid5 array
location: ubuntuforums.com - date: March 27, 2013
I am searching for the appropriate (ie. less risky) mdadm command to reassemble a double failed 4-partition raid5 array.
In my understanding (see test details below) I have 4 raid5 devices (partitions) ceasing to work after two of them was kicked out together from the array; two devices are known to have some (reproducable) read issues in a couple of sectors. Beside the read errors the state of the array members seems (see below) to be good. I have read the mdadm manual (more than once) and googling since two weeks, having collected a remarkable amount of useful information. However I still see more than one possible solutions at mdadm command level I can not see which is the best.
a) preliminary information
clean (no hardware raid mix) software raid by mdadm
raid5 was constructed from 4 partitions, no spare devices
(partition size set to 1998000 MB in cfdisk for each)
'sudo lshw --class disk --class storage' output is as follows
Questions about disk cloning with dd
location: ubuntuforums.com - date: September 12, 2010
When cloning one drive to another, does the target hard drive have to be formatted, or will dd effectively mirror everything, data and partitions, formatting on the fly?
If formatting is performed on the fly, is the formatting the same, e.g., ext4 --> ext4?
If the target drive is twice the size of the source drive, is the remaining space available to Gparted later, or is formatting and partitioning in advance necessary anyway to use this space in the future?
mdadm (RAID5) Degraded Array (removed disc)
location: ubuntuforums.com - date: November 6, 2013
I have been having terrible performance from a RAID5 made of 3, 2-TB drives. Doing some googling, I got to using some of the inquery commands and see that I'm having issues with the array. Now, I decided on that RAID configuration because I read about the (marginal) redundancy that I would have, so I hope all is not lost. Here are various outputs, I hope someone can point me in the right direction
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid5 sde1 sdd1
3907023872 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [_UU]
unused devices: <none>
sudo mdadm --examine /dev/sd[b,c,d,e]1
MBR Magic : aa55
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 31bacfd1:998e71ee:704e9500:29f029b7
Name : mike-server:0 (local to host mike-server)
Creation Time : Fri Aug 10 12:32:38 2012
Few questions about a basic home server HDD setup (Raid5 vs RaidZ)
location: linuxquestions.com - date: November 5, 2014
Hi, newbie here, first post. Been lurking around various threads for a while getting help over various things but haven't found quite the answers I need so thought I'd start a new thread.
I've been using linux since 2008 on and off (started on Ubuntu 8.10, moved to Mint when unity arrived, went back to windows for a while, now back on Mint 17) and have dabbled around with various distros, usually in VBox, though I'd still consider myself newbie-intermidiate.
I'm setting myself up a home server (I'll post links to the bits and pieces I've bought at the end of this post if anyone's interested) to do some basic things like file hosting, backups for mine & my wife's laptops, owncloud hosting and maybe more further down the line.
I'm leaning towards Centos 7 as my distro, though that's subject to change.
My biggest concern is what I'm going to do about my storage.
My new mobo has 5 sata ports, I currently have 3 spare 500gb 2.5" drives that I'll be using to start wit
Questions about "Hard Disk Installation" of Ubuntu10.04.
location: ubuntuforums.com - date: July 1, 2010
I have xp on sda, fedora 13 on sdb, and I want to install ubuntu 10.04
on sdc. I've been having lots of boot problems following my attempts
to install ubuntu, all coming down, I believe, to unreliable media.
I'm considering what Ubuntu's installation guide describes as "Hard Disk Booting," see
Ubuntu Documentation > Ubuntu 10.04 > Ubuntu Installation Guide > Obtaining System Installation Media > Preparing Files for Hard Disk Booting.
I can use my fedora installtion to carry out this process.
Ubuntu's installation guide breaks a hard disk installation into the following 3 steps.
1. Copy the files vmlinuz (kernel binary) and initrd.gz (ramdisk image)
from the Ubuntu archives to a convenient location on your hard drive, for instance to [Fedora's] /boot/newinstall/.
2. Add the following lines to [Fedora's] grub's menu.lst file:
title New Install
(hd1,0) because fedora is on the fir
Questions about Arch linux..
location: linux.com - date: October 25, 2011
So after discovering the latest Ubuntu release, I've decided to change linux distros. Ubuntu decided to go the user-friendly path with it's new update. I've always gone for somewhere in between user friendly and complex, and I should probably choose one or the other, so I'm interested in Arch Linux, and I have a few questions about it.
Is it a command line installer? I've heard you'll need to check out the wiki guide on installing, problem is can I view it while installing? otherwise I'm gonna have to print it out, which is a pain (since I don't have a separate laptop). I've heard Gentoo is the most confusing linux OS out there, and Arch looks pretty complex as well, so how confusing it in comparison?
Also, what desktop environment does it use?
I have no more blank cd's at the moment, so I'm going to install Linux Mint for now, but I would like to move onto something else at some point.
A few questions about creating an LVM
location: ubuntuforums.com - date: November 26, 2012
My current setup is a 18GB root, 400GB /home, 2GB swap, 80GB Windows.
Is /home automatically separated?
Can I reinstall root without wiping home?
How much space on my 500GB drive should be allocated to the LVM? It'll dual-boot with a Windows 8 partition. This partition will also be the one that both OSes share.
Questions about 13.04
location: ubuntuforums.com - date: September 4, 2013
Hello, I just deleted Windows 8 and installed Ubuntu 13.04, and I was wondering about downgrading to 12.04 LTS because apparently 13.04 will only be supported until January 2014. CAn someone shed some light on this? Is there any benefit to having the LTS? Or should I just wait to upgrade to 14.04?
Questions about Ubuntu Studio for Dell Latitude D620
location: ubuntuforums.com - date: September 25, 2013
I am a musician getting ready to do some experimenting with Linux-based music programs. I remember my days of using Anvil Studio and Audacity as well as Virtual Instruments on Windows, and I want to give it a try on Linux. Thing is, I'm not just a musician, I'm involved in other creative pursuits to the extent that Ubuntu Studio might be a possible choice.
Now here's the deal. I know about Audacity and SOME Virtual Instrument products (I can't afford an actual synth keyboard.), and I know Ubuntu Studio has these. But I know absolutely nothing about this JACK program (which I've read doesn't seem to work well on a Dell Latitude D620 laptop, which is what I have). What is JACK, and what's it really for? Do I absolutely have to use it in order to record ANY music at all? Is it involved with the Virtual Instrument programs, or can I just use the Virtual Instruments to hammer out and record ideas and save them for later working in Audacity (the program I'm most familiar with)?
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