Backup slow for linux server

[raj]

Hi Team,

I am running the latest version of proxmox. Server is IBMX3650 M3 with synology RS3614xs+ with SSD drives as storage. Synology is mounted as nfs to create a datastore for the vm storage. I have a windows 2012 vm running with 4 disk of 100GB but I have only 3 disk included in the backup. The backup for that windows VM takes 1 hour and 33 mins average with a total of 58.94GB and with zst. I have another VM running centos 7. Disk is 200GB and the time to do the backup takes 1 hour and 35 mins average with a total of 20.94 GB and with zst. Can anyone advise why its taking so long to backuphalf the amount of data.

Regards,

rajbps

 

[oguz]

hi,

the total size of the disk can be bigger, but that doesn't necessarily mean there's more data inside.

the size of backup depends on how much of the disk is filled.

please check how much data is actually in the disks

 

[raj]

Hi Oguz,

Sorry for this reply but how can I do that please. The disk is qcow2.

regards,

rajbps

 

[raj]

Here is what I can find

Filesystem Size Used Avail Use% Mounted on
devtmpfs 5.8G 0 5.8G 0% /dev
tmpfs 5.8G 0 5.8G 0% /dev/shm
tmpfs 5.8G 169M 5.7G 3% /run
tmpfs 5.8G 0 5.8G 0% /sys/fs/cgroup
/dev/mapper/centos-root 50G 15G 36G 30% /
/dev/mapper/centos-home 126G 33M 126G 1% /home
/dev/sda1 497M 294M 204M 60% /boot
tmpfs 1.2G 0 1.2G 0% /run/user/0

 

[oguz]

Disk is 200GB and the time to do the backup takes 1 hour and 35 mins average with a total of 20.94 GB and with zst. Can anyone advise why its taking so long to backuphalf the amount of data.

even if there's no data in most of the disk, the backup process still needs to go through the whole disk.

time for backups depend a lot on the storage backend, virtual disk type, network connection if NFS etc. being used, and so on.

you can try experimenting with different backup methods, compression algorithms, storage backends.