Knowledge Base (Posts about storage)

Save whole hard drive image

bgstack15 — Thu, 28 Sep 2023 13:13:41 GMT

I have some old hard drives (IDE connectors) I wish to backup. In my current solution, these old Windows XP-era-sized hard drives are a piece of cake to store. But how should I store them? They aren't compact discs, so genisoimage wouldn't cut it.

Here's how I chose to preserve them.

make disk image

time sudo qemu-img convert -c -O qcow2 /dev/sdd1 DOWNSTAIRS_PC.qcow2

mount image

sudo modprobe nbd max_part=8
sudo qemu-nbd --connect=/dev/nbd0 ~/DOWNSTAIRS_PC.qcow2
sudo fdisk /dev/nbd0 -l
sudo mount /dev/nbd0 /mnt/foo

when done

sudo umount /mnt/foo
sudo qemu-nbd --disconnect /dev/nbd0
sudo modprobe -r nbd

References

Make driver disk for CentOS

bgstack15 — Thu, 28 Nov 2019 14:17:38 GMT

Goals

If you want to make a generic USB driver disk for RHEL/CentOS, you can follow these instructions. The drivers are in rpm format, and you need those drivers during installation of a new system, primarily storage drivers.

Instructions

On an existing CentOS system, install the dependencies.

yum -y install createrepo squashfs-tools

Change directory to where your rpms and make a new directory tree.

cd path/to/rpms
export SQUASH_ROOT=./squashfs-root
mkdir -p "${SQUASH_ROOT}/rpms/x86_64"

Make a specific file with any contents you wish.

echo "My custom driver disk" > "${SQUASH_ROOT}/rhdd3"

Make a yum repository

cp -p *rpm "${SQUASH_ROOT}/rpms/x86_64/"
createrepo --basedir "${SQUASH_ROOT}/rpms/x86_64/" .

Make the driver disk-only components.

touch "${SQUASH_ROOT}/.rundepmod"
( cd "${SQUASH_ROOT}" ;
   for thisrpm in "${SQUASH_ROOT}/rpms/x86_64"/*rpm ;
   do
      rpm2cpio "${thisrpm}" | cpio -imVd ./lib/*
   done
)

And make the image file from the custom directory.

mksquashfs "${SQUASH_ROOT}" ./my-driver-disk.img

Clean up the custom directory if you're done with it! The image is now complete and we will use it for the last step.

rm -rf "${SQUASH_ROOT}"

Deploy the image onto your preferred disk drive. Be sure you know which drive is the flash drive you want!

sudo dd if=/path/to/my-driver-disk.img of=/dev/sdz

The image file should be really small, so there is no need to control block size (bs=2048). Also, this disk will not be directly readable to a regular system, so do not let that alarm you.

References

Weblinks

Find wwns for LUNs

bgstack15 — Sun, 23 Dec 2018 14:05:40 GMT

If you need to discover the wwns of your storage:

for word in $( find /dev/sd* -printf '%f\n' ) ; do printf "%s %s\n" "$( udevadm info -q all -p /block/${word} 2>/dev/null | awk -F'=' '/WWN_WITH_EXT/{print $2}' )" "/dev/${word}" ; done

ls -l /dev/disk/by-id/wwn*