Problem when uploading many files to Nextcloud 15 SMB Share

Nextcloud version (eg, 12.0.2): 15.0.0.10
Operating system and version (eg, Ubuntu 17.04): Ubuntu 18.04
Apache or nginx version (eg, Apache 2.4.25): nginx 1.14
PHP version (eg, 7.1): 7.2
Windows Client: 2.5.1
External Storage: SAMBA, Ubuntu 18.04: Mounting Active Directory user homeshares
Root of Nextcloud: NFS
NFS and SAMBA running on the same server behind a firewall.

The issue you are facing:
When uploading/syncing many small files from a Windows machine the smbclient get “stuck” and server is running at 100% CPU. This does not get better when replication is stopped or replication is completed.

No problem when uploading/syncing /the same folder to the root of Nextcloud (NFS)!

top - 18:52:56 up 58 min,  1 user,  load average: 12.04, 8.39, 4.67
Tasks: 175 total,  12 running, 100 sleeping,   0 stopped,   0 zombie
%Cpu(s): 22.7 us, 75.7 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.0 si,  1.6 st
KiB Mem :  2031112 total,  1487256 free,   239856 used,   304000 buff/cache
KiB Swap:   190916 total,   190916 free,        0 used.  1613120 avail Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
19220 www-data  20   0  345640  16404  13924 R  62.8  0.8   0:34.57 smbclient
 1151 www-data  20   0  347156  18116  13968 R  62.5  0.9  50:06.38 smbclient
14546 www-data  20   0  345508  16364  13880 R  56.1  0.8   3:29.06 smbclient
16657 www-data  20   0  345508  16272  13792 R  56.1  0.8   1:56.43 smbclient
 9858 www-data  20   0  345508  16260  13784 R  54.8  0.8   6:42.18 smbclient
14443 www-data  20   0  345508  16400  13924 R  54.2  0.8   3:36.59 smbclient
10218 www-data  20   0  345508  16276  13792 R  51.8  0.8   6:32.10 smbclient
17007 www-data  20   0  345508  16280  13804 R  49.5  0.8   1:51.98 smbclient
 7606 www-data  20   0  345508  16288  13812 R  48.8  0.8   8:14.29 smbclient
19361 www-data  20   0  345640  16336  13856 R  48.8  0.8   0:28.51 smbclient
14473 www-data  20   0  345508  16320  13844 R  47.2  0.8   3:35.29 smbclient
15281 www-data  20   0  651432  52292  35480 S   4.0  2.6   0:15.70 php-fpm7.2
  754 www-data  20   0  143848   9508   7124 S   0.3  0.5   0:32.35 nginx

The PIDs of the smbclient processes are not staying the same, constantly changing, so the only solution is to reboot the server.
The SMB share can still be accessed and files can be written to the share, but extremely slow (due to 100% CPU usage).

Is this the first time you’ve seen this error? (Y/N): Yes, first time trying to use external storage

Steps to replicate it:

  1. Activate exteral Storage
  2. Add SMB Share
  3. Sync lot of small files (e.g. 1000 JPGs) via LAN

The output of your Nextcloud log in Admin > Logging: Empty

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

<?php
$CONFIG = array (
  'instanceid' => 'xxx',
  'passwordsalt' => 'xxx',
  'secret' => 'xxx',
  'trusted_domains' =>
  array (
    0 => 'URL',
    1 => 'URL',
  ),
  'datadirectory' => '/data/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '15.0.0.10',
  'overwrite.cli.url' => 'https://',
  'dbname' => 'nextcloud2',
  'dbhost' => '192.168.xx.xx',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'USR',
  'dbpassword' => 'PWD',
  'installed' => true,
  'mail_from_address' => 'cloud',
  'mail_smtpmode' => 'smtp',
  'mail_sendmailmode' => 'smtp',
  'mail_domain' => 'xx',
  'mail_smtpauthtype' => 'xx',
  'mail_smtphost' => '192.168.xx.xx',
  'mail_smtpport' => '25',
  'ldapIgnoreNamingRules' => false,
  'ldapProviderFactory' => 'OCA\\User_LDAP\\LDAPProviderFactory',
  'memcache.local' => '\OC\Memcache\APCu',
);

The output of your Apache/nginx/system log in /var/log/____: No Error

Unfortunately I can’t find a smbclient logfile or any error messages in the SAMBA server log.

Thank you in advance for any help!

Best regards, Kurt

Problem solved by installing “php-smbclient”.