When creating full images from one of my rootdisks …
dd if=/dev/sda | bzip2 >/opt/backup/sda.img.bzip2
… i noticed the backups were growing, but the amount of data on the device was not.
Since dd is a full blocklevel- and not a filebased backup, there must be some free space containing old bits and bytes.
The sfill utility can overwrite the freespace with zeroes, giving me better compressed images.
sfill -f -l -l -z /mnt/mountpoint
My script to clean up some stuff.
Seems that those kernel header packages are eating up all inodes on small ext volumes.
#!/bin/sh nr_of_removed_packages=`dpkg -l | egrep "^rc" | cut -d" " -f3 | wc -l` nr_of_active_kernels=`ls /boot/vmlinuz* | wc -l` active_kernels=`ls /boot/vmlinuz* | cut -d" " -f9 | sed -r 's/\/boot\/vmlinuz-//' | sed -r 's/-generic//'` nr_of_headers_to_be_cleaned=`dpkg -l | grep linux-headers | grep -v headers-generic | cut -d" " -f3 | grep -v "$active_kernels" | wc -l` if [ "$nr_of_removed_packages" -gt "0" ]; then echo "Purge configuration files for removed packages ($nr_of_removed_packages)" dpkg --purge `dpkg -l | egrep "^rc" | cut -d" " -f3` else echo "No removed packages" fi if [ "$nr_of_headers_to_be_cleaned" -gt "0" ]; then echo "Cleaning old kernel headers, but skipping active kernels:" echo "$active_kernels" echo "" echo "Going to clean:" dpkg -l | grep linux-headers | grep -v headers-generic | cut -d" " -f3 | grep -v "$active_kernels" echo "Wait 5 seconds or break now!!" sleep 5 dpkg --purge `dpkg -l | grep linux-headers | grep -v headers-generic | cut -d" " -f3 | grep -v "$active_kernels"` else echo "No kernel headers to be cleaned" fi echo "Done!"
Build/format/mount encrypted LVM volume
cryptsetup -y -v luksFormat /dev/sdc1 cryptsetup luksOpen /dev/sdc1 encrypted-sdc1 pvcreate /dev/mapper/encrypted-sdc1 vgcreate MAIN /dev/mapper/encrypted-sdc1 lvcreate -n LVMAIN -l 100%FREE MAIN mkfs.ext4 /dev/MAIN/LVMAIN mount /dev/MAIN/LVMAIN /mnt/lvmtest
Build expansion volume
cryptsetup -y -v luksFormat /dev/sdc2 cryptsetup luksOpen /dev/sdc2 encrypted-sdc2 pvcreate /dev/mapper/encrypted-sdc2
Extend the volumegroup and Logical Volume
vgextend MAIN /dev/mapper/encrypted-sdc2 vgdisplay (and look for the free PE's) lvextend -l +1830 /dev/MAIN/LVMAIN
(Online) grow the filesystem
resize2fs /dev/MAIN/LVMAIN
Shutdown procedure
umount /mnt/lvmtest vgchange -an MAIN cryptsetup luksClose /dev/mapper/encrypted-sdc2 cryptsetup luksClose /dev/mapper/encrypted-sdc1
Start again
cryptsetup luksOpen /dev/sdc1 encrypted-sdc1 cryptsetup luksOpen /dev/sdc2 encrypted-sdc2 vgscan --mknodes vgchange -ay mount /dev/MAIN/LVMAIN /mnt/lvmtest
This example hot-migrates an existing LVM volume spanned over 3 disks to a new LVM volume spanned over 3 disks.
Prerequisites:
This first part you probably already have, since you want to migrate this volume. But i’m going to create it anyway as part of the whole documentation.
I’m not going to work with partitions and just use the whole disks.
Create the Pysical Volumes
root@lvmtest:~# pvcreate /dev/sdb /dev/sdc /dev/sdd Physical volume "/dev/sdb" successfully created Physical volume "/dev/sdc" successfully created Physical volume "/dev/sdd" successfully created
Create the Volume Group
root@lvmtest:~# vgcreate MAIN /dev/sdb /dev/sdc /dev/sdd
Create the Logical Volume
root@lvmtest:~# lvcreate -n LVMAIN -l 100%FREE MAIN Logical volume "LVMAIN" created
Create the filesystem, mount it
root@lvmtest:~# mkfs.xfs /dev/MAIN/LVMAIN root@lvmtest:~# mkdir /mnt/mylvmvolume root@lvmtest:~# mount /dev/MAIN/LVMAIN /mnt/mylvmvolume root@lvmtest:~# df -h | grep MAIN /dev/mapper/MAIN-LVMAIN 24G 33M 24G 1% /mnt/mylvmvolume
Put some data on it
root@lvmtest:/mnt/mylvmvolume# dd if=/dev/zero of=blabla.txt bs=1M count=1000 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 5.93346 s, 177 MB/s
Add new disks to the machine.
Prepare the new disks:
root@lvmtest:~# pvcreate /dev/sde /dev/sdf /dev/sdg Physical volume "/dev/sde" successfully created Physical volume "/dev/sdf" successfully created Physical volume "/dev/sdg" successfully created
Add the disks to the existing Volume Group
root@lvmtest:~# vgextend MAIN /dev/sde /dev/sdf /dev/sdg
Create a mirror (-m1) of the current data to the recently added space.
Do this in a screen. This can take days, depending on the size!
root@lvmtest:~# lvconvert -m1 --corelog MAIN/LVMAIN /dev/sde /dev/sdf /dev/sdg MAIN/LVMAIN: Converted: 0.0% MAIN/LVMAIN: Converted: 2.8% MAIN/LVMAIN: Converted: 10.6% MAIN/LVMAIN: Converted: 20.2% MAIN/LVMAIN: Converted: 29.9% MAIN/LVMAIN: Converted: 39.1% MAIN/LVMAIN: Converted: 48.8% MAIN/LVMAIN: Converted: 58.3% MAIN/LVMAIN: Converted: 67.8% MAIN/LVMAIN: Converted: 77.5% MAIN/LVMAIN: Converted: 87.1% MAIN/LVMAIN: Converted: 96.8% MAIN/LVMAIN: Converted: 100.0%
The mirror is live.
During the conversion, you might see some nice figures using iostat
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn sdb 126.00 0.00 63.00 0 126 sdc 0.00 0.00 0.00 0 0 sdd 0.00 0.00 0.00 0 0 sde 126.00 63.00 0.00 126 0 sdg 0.00 0.00 0.00 0 0 sdf 0.00 0.00 0.00 0 0 sda 0.00 0.00 0.00 0 0 dm-0 0.00 0.00 0.00 0 0 dm-1 1004.00 62.75 0.00 125 0 dm-2 1008.00 0.00 63.00 0 126
Create 0 copies (-m0) for the devices that will be removed, a.k.a. breaking the mirror.
root@lvmtest:~# lvconvert -m0 MAIN/LVMAIN /dev/sdb /dev/sdc /dev/sdd
Remove the devices from the Volume Group
root@lvmtest:~# vgreduce MAIN /dev/sdb /dev/sdc /dev/sdd Removed "/dev/sdb" from volume group "MAIN" Removed "/dev/sdc" from volume group "MAIN" Removed "/dev/sdd" from volume group "MAIN"
Remove the Physical Volumes
root@lvmtest:~# pvremove /dev/sdb /dev/sdc /dev/sdd Labels on physical volume "/dev/sdb" successfully wiped Labels on physical volume "/dev/sdc" successfully wiped Labels on physical volume "/dev/sdd" successfully wiped
That’s it.. Hot migrated!
root@lvmtest:~# df -h | grep MAIN /dev/mapper/MAIN-LVMAIN 24G 11G 14G 42% /mnt/mylvmvolume
HP’s website didn’t seem to work today. Just when i needed an offline ACU iso.
Seems they can be found here:
ftp://ftp.hp.com/ftp1/pub/softlib2/software1/pubsw-windows/p1067040366/