Symptoms

Backups "Completed with exception" due to "Resource temporarily unavailable" Many files are being skipped and in the logs, shows: /ifs/data/path/to/the/documentation/file.txt, ACL, errorCode: 11, Resource temporarily unavailable From the dmesg logs from the NAS proxy processing the backup, for a few folders, the skipped ones, ACL size is greater than 16KB: 2026-03-02T01:46:41.100036+03:00 proxy01 kernel: [401058.407510][T12186] CIFS: VFS: \\NAS_ARRAY_FQDN SMB response too long (33696 bytes) 2026-03-02T01:46:41.100060+03:00 proxy01 kernel: [401058.407563][T13459] CIFS: VFS: cifs_xattr_get: error -11 getting sec desc 2026-03-02T01:46:41.188033+03:00 proxy01 kernel: [401058.495471][T12186] CIFS: VFS: \\NAS_ARRAY_FQDN SMB response too long (33752 bytes) 2026-03-02T01:46:41.272041+03:00 proxy01 kernel: [401058.579956][T12186] CIFS: VFS: \\NAS_ARRAY_FQDN SMB response too long (33696 bytes) 2026-03-02T01:46:41.388036+03:00 proxy01 kernel: [401058.696871][T12186] CIFS: VFS: \\NAS_ARRAY_FQDN SMB response too long (33752 bytes) 2026-03-02T01:46:41.472053+03:00 proxy01 kernel: [401058.780959][T12186] CIFS: VFS: \\NAS_ARRAY_FQDN SMB response too long (33696 bytes) 2026-03-02T01:46:41.840026+03:00 proxy01 kernel: [401059.146713][T12186] CIFS: VFS: \\NAS_ARRAY_FQDN SMB response too long (33696 bytes)

Cause

cfs.co has a default CIFSMaxBufSize = 16KB, so the limit is reached.

Resolution

Engineering created a script that must be run on each NAS proxies in the environment. Script name attached to this article: setup_cifs_module.sh 1- Connect to the NAS proxies. To get the credential, refer to the NAS guide PowerProtect Data Manager 19.22 Network-Attached Storage User Guide page 96. 2- Transfer the script to each NAS proxy using WinSCP or any other SCP method, in /home/admin 3- Run the following: ./setup_cifs_module.sh After the script ran, the NAS proxies must be rebooted.

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