Percona: Backup preparation doesn't work ("cannot open ./xtrabackup_logfile")

I've created a MySQL backup with PerconaXtrabackup tool via (thanks to this guide):

innobackupex --user=backupmysqluser --password=xyz --compress --stream=xbstream ./ > /var/backups/db/firstBackup.db

It succeeds creating the hot backup. Now I want to test the restoration of it, so then, first, I decompress it:

cd /var/backups/db
mkdir decompressed
xbstream -x -C decompressed

Now I try to prepare it:

innobackupex --apply-log /var/backups/db/decompressed/

And the result is this error:

160719 20:06:28 innobackupex: Starting the apply-log operation

IMPORTANT: Please check that the apply-log run completes successfully.
           At the end of a successful apply-log run innobackupex
           prints "completed OK!".

innobackupex version 2.4.3 based on MySQL server 5.7.11 Linux (x86_64) (revision id: 6a46905)
xtrabackup: cd to /var/backups/db/decompressed
xtrabackup: This target seems to be not prepared yet.
InnoDB: Number of pools: 1
InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
xtrabackup: Warning: cannot open ./xtrabackup_logfile. will try to find.
InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
  xtrabackup: Fatal error: cannot find ./xtrabackup_logfile.
xtrabackup: Error: xtrabackup_init_temp_log() failed.

It's strange because in the decompressed folder there's no xtrabackup_logfile, but there is a file named xtrabackup_logfile.qp instead.

What did I do wrong?

You have not decompressed the Xtrabackup files if they still have the .qp extension.

Try using this inside the current folder:

sudo innobackeupex --decompress --parallel=4


where 4 stands for the number of threads you would like to use.

Also, for clean-up afterwards:

sudo find ${DEST_DIR}/ -name "*.qp" -delete

StackExchange Database Administrators Q#144309, answer score: 5