Here is an easy way to restore things if you have the starting point and size of each partition using fdisk:
In this example we pretend that /dev/sda was wiped out, but the running system still has the info in /sys/class/block/sda
Go into each partition and record the "start" and "size"
hostdev@box /sys/class/block/sda/sda1 $ cat start
2048
hostdev@box /sys/class/block/sda/sd........
If you are doing a custom deployment and image, make sure that when you rsync'd or tar'd that you didn't mess up the symlnk of /etc/mtab to /proc/self/mounts
ln --force -s /proc/self/mounts /etc/mtab
Will fix this........
The reason for doing this is that the installer doesn't seem to work properly for LUKS and the server installer doesn't even support LUKS anymore. When you use the GUI install on Desktop for LUKS it won't boot and will just hang after you enter your password. So the only reliable way is to do it ourselves.
1.) Make a default minimal install of Ubuntu
2.) Have a secondary disk on the server or VM.
3.)........
The cool thing here is that we only need 1 drive to make a RAID 10 or RAID 1 array, we just tell the Linux mdadm utility that the other drive is "missing" and we can then add our original drive to the array after booting into our new RAID array.
Step#1 Install tools we need
yum -y install mdadm rsync
Step #2 Create your partitions on the drive that will be our RAID array
Here I assume it is /dev........
Use fdisk on your USB drive to create a bootable NTFS partition (in my case /dev/sdb):
sudo fdisk /dev/sdb
Welcome to fdisk (util-linux 2.27.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)........
The strange thing is that usually the first install or two will work on any new machine but then it suddenly won't. I had this experience on QEMU 2.13 on a different machine. There is something finicky or buggy about the CUCM installer even when choosing the same virtual hardware specs.
qemu-kvm command:
/usr/libexec/qemu-kvm -version
QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2-2.506.el6_10.1), Copyright (c) 2003-2008 Fabrice Bellard
........
On a test machine Iwas never able to access to a newly created 4th partiton. As we can see there are dev devices for everything but the 4th partition.
The normal "partprobe" or "kpartx" or kernel being told to rescan the block device didn't help (only a reboot did).
fdisk -l /dev/sda
Disk /dev/sda: 750.2 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders
Units........
The easiest way is to use SSHand DD or a combination of netcat. SSHwill be a little slower due to encryption but is the most secure way (on two older systems the average clone speed is about 40-50MB/s). This is also OS independent as it doesn't matter what the source OS is because you are literallly cloning the drive so you retain the partition table and settings.
Clone HDD using SSH and DD........
I don't recall having this issue in the distant past but nowadays at least Debian seems to be very picky about this.
I used dd to copy one hard drive to another and tried booting it. Everything seemed fine with grub working but each time it would drop to the busybox shell. There is no particular error so this is misleading.
Normally the first things you would check are to make sure your fstab is correct (that the UUID is correct)and that you've updated grub.&........
virt-list-partitions kvmusertest.img
/usr/bin/supermin-helper exited with error status 1.
To see full error messages you may need to enable debugging.
See http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs at /usr/bin/virt-list-partitions line 177.
#solution
update-guestfs-appliance........
1.) Replicate the number of partitions in your new drives.
gdisk /dev/sda
gdisk /dev/sdb
I created 3 partitions of the same same size.
partition #1: +1G (/boot)
partition #2: +60G (swap)
partition #3: rest of it (/)
#note if you are using GPT/gdisk you need to create separate a partition at least 1MB in size (in my case I would a 4th partition and mark it type ef02).........
sudo fdisk /dev/sdh
WARNING: GPT (GUID Partition Table) detected on '/dev/sdh'! The util fdisk doesn't support GPT. Use GNU Parted.
WARNING: The size of this disk is 8.0 TB (8001563221504 bytes).
DOS partition table format can not be used on drives for volumes
larger than (2199023255040 bytes) for 512-byte sectors. Use parted(1) and GUID
partition table format (GPT).
The device presents a l........
Device Boot Start End Blocks Id System
/dev/sdc1 1 132 1060256+ fd Linux raid autodetect
Partition 1 does not end on cylinder boundary.
Partition 1 does not start........
grub> root (hd0,0)
root (hd0,0)
Filesystem type is ext2fs, partition type 0xfd
grub> setup (hd0)
setup (hd0)
But if you do:
root (hd1,0)
setup (hd1)
it does work, I think hd0/sda had a GPT partition that was not removed properly (what I did was just dd bs=512 count=1 the partition table from another drive since the partition table should be identical).
Checking if "/boot/grub/........
In this example we have 2 drives in a RAID array and /dev/sdb is the one that failed. /dev/sda1 is also the /boot partition which we tell grub to install on /dev/sdb eg install root (hd0,0) /dev/sda1 on the new drive /dev/sdb (hd1)
First copy the partition table from /dev/sda to /dev/sdb
dd if=/dev/sda of=/dev/sdb bs=512 count=1
Run partprobe to detect the new partition table
partprobe........
Here is the scenario you or a client have a remote machine that was installed as a standard/default minimal Centos 6.x machine on a single disk with LVM for whatever reason. Often many people do not know how to install it to a RAID array so it is common to have this problem and why reinstall if you don't need to? In some cases on a remote system you can't easily reinstall without physical or KVM access.
So in this case you add a second physical or disk or already ha........
This was caused by some weird dmraid setup which kind of takes control of drives even if they're blank/unused.
1. Check the table.
dmsetup table
ddf1_44656c6c202020201000006010281f0b3f5195b77cf86172: 0 3905945600 linear 8:0 0
ddf1_44656c6c202020201000006010281f0b3f5195b77cf86172p3: 0 37124096 linear 253:0 284547072
ddf1_44656c6c202020201000006010281f0b3f5195b77cf86172p2: 0 283496448 linear 253:0 1050624
ddf1_44656c6c2020202010........
This booting error is because the Xen PV guest image uses the Xen kernel, this is not compatible with anything but a host running a Xen kernel.
I did a kpartx -av virtual.img and then it created some partitions that showed up in fdisk.
I mounted it and did a chroot into it and removed the xen kernel and installed a normal kernel but Xen still shows the same kernel in Grub (only the Xen one).
This is strange but it seems like this Xen PV guest has some sort of hidden or........
I backed up everything in the /mnt/sd_card directory thinking that some dataloss could occur for some reason but purposely left my microSDHC unbacked up thinking that "it won't touch that since it's external" and Samsung's and other manufacturers website even say this (that it won't be affected and not to worry etc).
Apparently I was wrong, my microSD was "undetected" and asked to be formatted after the upgrade (there goes 3-months worth of family photos). No........
fdisk -lu VPS.img
last_lba(): I don't know how to handle files with mode 81ed
You must set cylinders.
You can do this from the extra functions menu.
Disk VPS.img: 0 MB, 0 bytes
255 heads, 63 sectors/track, 0 cylinders, total 0 sectors
Units = sectors of 1 * 512 = 512 bytes
Device Boot Start End ........
There's no partial WD EARS alignment fix:
I had data on /dev/sda3 and /dev/sdb3 (RAID1) so I couldn't edit that one.
I thought I'd be smart and try fixing the first two partitions so I set the first one starting at sector 2048 and then +8 for the second partition.
This has really slowed the performance down worse than it ever was!
Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, tot........
I wanted to Import/Use a .vmdk hard disk image file from VMWare. Generally you can just "point" VirtualBox to it and use it and it will work but I found an exception.
One of my Centos 4.4 x64 images wouldn't boot. I had two copies, an older one and the newer one. The older one booted as normal (once I changed the VirtualBox driver to IDE from SATA). The newer one stopped at the "GRUB loading" message no matter what I tried.
As far as........
Create New RAID 1 Array:
First setup your partitions (make sure they are exactly the same size)
In my example I have sda3 and sdb3 which are 500GB in size.
mdadm --create /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3
mdadm: array /dev/md2 started.
Check Status Of The Array
*Note I already have other arrays md0 and md1.
You can see below that md2 is syn........
*Note OS X is strange to install, I thought my HDD was not being detected by you just have to go to Diskutil and create a partition for the root filesystem and then close/move the Window and proceed with the install.
After install Mac OS X 10.4.6 Tiger I get a black screen that says:
b0 error
Most people say the partition has to be marked as "active", actually that just means marked as "bootable". Instead of t........
I was creating a RAID array and got this error: mdadm: /dev/sda1 is too small: 0K
mdadm: create aborted
Of course sda1 is not too small, both partitions sda1 and sdb1 are identical in size:
Disk /dev/sda: 2000.3 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000000
Device Boot Sta........
Partclone is a great tool that is basically like dd only it does not waste space, it doesn't take the whole partition, yet it does the same thing as dd, only with huge space/cost savings.
Clonezilla uses partclone and is more of an integrated/easy to use suite I guess you could say. I've personally only used partclone but I wish there was an easy way to mount partclone images.
I believe with Clonezilla you can do that, so I will probably give it a shot next time.........
I successfully created a single RAID 1 partition which includes /boot inside it and my root directory through the Debian installer. It said GRUB installed successfully but when I try booting the OS it seems GRUB can't read anything.
When trying to boot from GRUB
GRUB Loading stage 1.5.
GRUB loading, please wait...
Error 2
I get "Error 2" when trying to boot Debian. I also notice from a LiveCD that........
Before we start I take no responsibility for this, you should have a backup and if you make a mistake during this process you could wipe out all of your data. So backup somewhere else before starting this as a precaution, or make sure it's data you could afford to lose.
The RAID 1 Setup (Hardware Wise)
I've already setup my 2 x 1TB (Seagate) drives with identical partitions, make sure your new hard drive (the empty one) is setup like your curr........
You can see the problem below, GRUB recognizes my hard drive and sees the partitions but cannot access them. This is from the GRUB boot disc I'm using.
What happened is that I had some power issues causing this system's power to be interrupted several times and basically an on/off on/off situation.
The system won't boot, I just get a flashing cursor and no message or error from GRUB. Obviously the problem is that my MBR seems corrupt or some other issue.
My........
The dmg format is silly and annoying to work with, why couldn't Apple stick with the .iso standard? Anyway, there's an excellent Linux and Windows based tool to convert it back to a normal .iso Image called dmg2iso
I'll only cover theLinux version although the Windows pre-built binary works the same way.
Download dmg2iso here for free (from the author's website)
It's just silly and doesn't make sense that Ubuntu doe........