pbzip2 process consumes a lot of CPU during daily AutoFTP backup task

Symptoms 

pbzip2 process consumes a lot of CPU during daily AutoFTP backup task, all CPU cores are busy despite the settings set in Dashboard > Nodes > node_name > Auto FTP Backup > pbzip2 Threads (Xen/KVM)

Process tree shows that there is no parameter passed for pbzip2 during its invokation:

# ps auxxffww | grep pbzip
root 32327 0.0 0.0 4144 492 pts/0 S+ 08:53 0:00 | \_ /usr/local/solusvm/core/solusvmc-vz --ftpdumpxenhvmpbzipthreads /tmp/dump-226.bz kvm112 solusvm 6
root 32328 0.0 0.0 106080 1288 pts/0 S+ 08:53 0:00 | \_ sh -c dd if=/dev/solusvm/kvm112_snapshot | pbzip2 | dd of=/tmp/dump-226.bz
root 32330 145 0.1 202908 9984 pts/0 Sl+ 08:53 0:13 | \_ pbzip2
root 32339 0.0 0.0 103324 872 pts/1 S+ 08:53 0:00 \_ grep pbzip

Cause

This behavior caused by the SolusVM bug #SVM-1093 and considered to be fixed in future.

Resolution

WARNING: The following patch should be applied with caution as it is a custom fix and can work incorrectly on particular circumstance.

1. Connect to the server via SSH
2. Download patched solusvmc-vz file:

   # cd /root/

   # wget https://solus.zendesk.com/hc/article_attachments/360017855471/solusvmc-vz.patched

3. Create a backup of the original file:

   # cp -a /usr/local/solusvm/core/solusvmc-vz /root/solusvmc-vz.original

4. Replace the original file with the patched one:

   # cp /root/solusvmc-vz.patched /usr/local/solusvm/core/solusvmc-vz

5. Check the permissions and md5sums of the executable:

   # md5sum /usr/local/solusvm/core/solusvmc-vz
   4897f85803aeebb2a48333e1c0baba49 /usr/local/solusvm/core/solusvmc-vz
   # stat /usr/local/solusvm/core/solusvmc-vz
   File: ‘/usr/local/solusvm/core/solusvmc-vz’
   Size: 63696 Blocks: 128 IO Block: 4096 regular file
   Device: fd00h/64768d Inode: 33583440 Links: 1
   Access: (6777/-rwsrwsrwx) Uid: ( 0/ root) Gid: ( 0/ root)