Disk extension for preprod and containers prod (ovh2)

We got alerts on low disk space on preprod VM (dockers (200) on ovh2)

We added disk space in proxmox to this machine and the container machine but we still add to make it available on the system side.

Operation was done on ovh2, VM dockers (200) and VM dockers-prod (201)

Snapshoting

Before this delicate operation, we snapshoted the VM in proxmox.

Extending partition size

This is the commands we run to make it happens.

Install tools:

apt install parted etckeeper

The swap partition is after the main partition, so we will have to remove it, resize main partition and recreate it.

Turn swap off:

swapoff -a

Edit partition.

parted /dev/sda
# change unit to sectors
(parted) u
Unit?  [compact]? s
# print partition table
(parted) p
Number  Start   End    Size    Type      File system     Flags
 1      1049kB  274GB  274GB   primary   ext4            boot
 2      274GB   275GB  1022MB  extended
 5      274GB   275GB  1022MB  logical   linux-swap(v1)
# note tha swap partition is to 534872062 536868863 (1996802 sectores in size)
# remove swap partitions
(parted) rm 5
(parted) rm 2
# print to check
(parted) p
Number  Start  End         Size        Type     File system  Flags
 1      2048s  534870015s  534867968s  primary  ext4         boot
# resize partition 1, leaving space for swap
(parted) resizepart 1 -1996801
Warning: Partition /dev/sda1 is being used. Are you sure you want to continue?
Yes/No? y
# print
umber  Start  End         Size        Type     File system  Flags
 1      2048s  627148799s  627146752s  primary  ext4         boot
# recreate swap (Start is end of part 1 + 1)
(parted) mkpart
Partition type?  primary/extended? primary
File system type?  [ext2]? linux-swap
Start? 836864000
End? -1s
(parted) quit

:pencil: Note: 1. we switch units to sectors because it helps having better aligned partitions (by multiples of 2048 in this case) 2. The swap partition was on an extended partition, but we put it back as a simple partition

We recreated swap, now we have to format it:

mkswap /dev/sda2

show new uids:

blkid

/dev/sda1: UUID="082b4523-f4d6-4d39-b5dd-48c5bdba2541" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="1a39b366-01"
/dev/sr0: BLOCK_SIZE="2048" UUID="2021-08-14-10-10-00-00" LABEL="Debian 11.0.0 amd64 n" TYPE="iso9660" PTUUID="3c15dbf8" PTTYPE="dos"
/dev/sda2: UUID="f8e99f04-88eb-4550-9308-10a470175e45" TYPE="swap" PARTUUID="1a39b366-02"

Change /etc/fstab accordingly (sda1 UUID did not change, only swap changed):

# / was on /dev/sda1 during installation
UUID=082b4523-f4d6-4d39-b5dd-48c5bdba2541 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda2 during installation
UUID=f8e99f04-88eb-4550-9308-10a470175e45 none            swap    sw              0       0

We should have booked our operation in etckeeper (not done on dockers-prod, etckeeper was not yet installed)

etckeeper commit "changed partition size"

Now we resized the partition, but we have to resize the filesystem. Let's resize sda1:

resize2fs /dev/sda1

Reactivate swap:

swapon -a

Let's see our changes:

df -h /
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1       294G  187G   93G  67% /