vzdump - bwlimit only on write speeds?

[hellomotow]

Right now I have set the bandwidth limit to 30000Kbps

/etc/vzdump.conf
bwlimit: 30000

Is there a way to only do this for write speed? The issue I have is large virtual machines that are allocated 500GB+ disk space but are only using up 50GB are taking much longer than they should as it reads the whole 500GB at 30mb/s

 

[wolfgang]

Hi,

if you like to set the write limit then you have to use the storage bwlimit and not the vzdump bwlimit.

Bandwidth Limit
       Restoring one or more big backups may need a lot of resources, especially storage bandwidth for both reading from the backup storage and writing
       to the target storage. This can negatively effect other virtual guest as access to storage can get congested.

       To avoid this you can set bandwidth limits for a backup job. Proxmox VE implements two kinds of limits for restoring and archive:

       •   per-restore limit: denotes the maximal amount of bandwidth for reading from a backup archive

       •   per-storage write limit: denotes the maximal amount of bandwidth used for writing to a specific storage

       The read limit indirectly affects the write limit, as we cannot write more than we read. A smaller per-job limit will overwrite a bigger
       per-storage limit. A bigger per-job limit will only overwrite the per-storage limit if you have ‘Data.Allocate’ permissions on the affected
       storage.

       You can use the ‘--bwlimit <integer>` option from the restore CLI commands to set up a restore job specific bandwidth limit. Kibit/s is used as
       unit for the limit, this means passing `10240’ will limit the read speed of the backup to 10 MiB/s, ensuring that the rest of the possible storage
       bandwidth is available for the already running virtual guests, and thus the backup does not impact their operations.

           Note
           You can use ‘0` for the bwlimit parameter to disable all limits for a specific restore job. This can be helpful if you need to restore a very
           important virtual guest as fast as possible. (Needs `Data.Allocate’ permissions on storage)

       Most times your storage’s generally available bandwidth stays the same over time, thus we implemented the possibility to set a default bandwidth
       limit per configured storage, this can be done with:

           # pvesm set STORAGEID --bwlimit KIBs

 

[Datenfalke]

Dear Wolfgang,

is the "storage bwlimit" functional for LVM-Thin volumes? I get the following error:

# pvesm set local-lvm --bwlimit 40960
400 Parameter verification failed.
bwlimit: invalid format - value without key, but schema does not define a default key

pvesm set <storage> [OPTIONS]

I am on pve-manager/6.2-10 and struggling on setting a bandwidth limit which does not stop all other container in a node while migrating one container to this node.

Setting /etc/pve/datacenter.cfg through the GUI is not effective:

bwlimit: clone=40960,default=40960,migration=40960,move=40960,restore=40960

And also setting of

bwlimit: 40960

in /etc/vzdump.conf is not effective.

Migration from LVM-thin to LVM-thin on the other node is with full bandwidth of 1 GBit/s crashing the other containers and VMs.

I think that settings in /etc/vzdump.conf worked before the uprade PVE 5 to 6, because I was able to migrate with a given rate limit.

Do I miss something?

Thank you!
Falco

 

[Walter Farmer]

The same issue happended to me too. But now everything is ok.

I have a small question.

is it possible to add a SSD to a CEPH-OSD on a running clusternode?

Thank for your help.

 

[tuxick]

The same issue happended to me too. But now everything is ok.

I have a small question.

is it possible to add a SSD to a CEPH-OSD on a running clusternode?

Thank for your help.

So how was it solved?

 

[tuxick]

Hi,

if you like to set the write limit then you have to use the storage bwlimit and not the vzdump bwlimit.

Bandwidth Limit
       Restoring one or more big backups may need a lot of resources, especially storage bandwidth for both reading from the backup storage and writing
       to the target storage. This can negatively effect other virtual guest as access to storage can get congested.

       To avoid this you can set bandwidth limits for a backup job. Proxmox VE implements two kinds of limits for restoring and archive:

       •   per-restore limit: denotes the maximal amount of bandwidth for reading from a backup archive

       •   per-storage write limit: denotes the maximal amount of bandwidth used for writing to a specific storage

       The read limit indirectly affects the write limit, as we cannot write more than we read. A smaller per-job limit will overwrite a bigger
       per-storage limit. A bigger per-job limit will only overwrite the per-storage limit if you have ‘Data.Allocate’ permissions on the affected
       storage.

       You can use the ‘--bwlimit <integer>` option from the restore CLI commands to set up a restore job specific bandwidth limit. Kibit/s is used as
       unit for the limit, this means passing `10240’ will limit the read speed of the backup to 10 MiB/s, ensuring that the rest of the possible storage
       bandwidth is available for the already running virtual guests, and thus the backup does not impact their operations.

           Note
           You can use ‘0` for the bwlimit parameter to disable all limits for a specific restore job. This can be helpful if you need to restore a very
           important virtual guest as fast as possible. (Needs `Data.Allocate’ permissions on storage)

       Most times your storage’s generally available bandwidth stays the same over time, thus we implemented the possibility to set a default bandwidth
       limit per configured storage, this can be done with:

           # pvesm set STORAGEID --bwlimit KIBs

I tried setting that for pbs storage, but getting errors like "update storage failed: unexpected property 'bwlimit'" Not supported for PBS?

 

[shallax]

For other people who stumble upon this, this is what allowed the command to be executed me:

pvesm set [StorageName] --bwlimit default=51200

You can also add ",clone=X,migration=X,move=X,restore=X"

However, this did not achieve the goal of limiting backup speeds as even with this set, backups still seemed to go at full speed.