Known limitations of cloud services

This topic describes the limitations that are identified for cloud services.

mmcloudgateway files migrate * on a parent folder does not move all files within the subfolders

Running the mmcloudgateway files migrate command to migrate all files (including the files within the subfolders) does not migrate all files within subfolders. It migrates only the leaf files within the current folder, from which the migrate command is issued. The migrate process skips the subfolders, by displaying the following warning message:

MCSTG00051E: File is not a regular file. Migration requests only support regular files.
error processing /<file-system-mount>/<folder1>/<folder-2>….

To migrate all files (including files within the subfolders) in one go, issue this command:

find <gpfs-mountpoint-folder-or-subfolder> -type f –exec mmcloudgateway files migrate {} +

This command passes the entire list of files to a single migrate process in the background as follows:

mmcloudgateway files migrate <file1> <file2> <sub-folder1/file1> <sub-folder2/file1> ……

Migrating transparent cloud tiering specific configuration to cloud storage might lead to issues

While you move data to an external cloud storage tier, it is required not to migrate files within the transparent cloud tiering internal folder (.mcstore folder within the configured GPFS file system) to cloud storage. It might lead to undesirable behavior for the transparent cloud tiering service. To address this issue, include the EXCLUDE directive in the migration policy.

Refer to the /opt/ibm/MCStore/samples folder to view sample policies that can be customized as per your environment and applied on the file system that is managed by transparent cloud tiering.

Running mmcloudgateway files delete on multiple files

Trying to remove multiple files in one go with the mmcloudgateway files delete delete-local-file command fails with a NullPointerException. This happens while you clean up the cloud metrics. Issue this command to remove the cloud objects:

find <gpfs-file-system> -type f -exec mmcloudgateway files delete {} \;

Range reads from the Cloud Object Storage is not supported for transparent recall.

When a file is transparently recalled, the file is entirely recalled.

Policy-based migrations

Policy-based migrations should be started only from transparent cloud tiering server nodes. Client nodes should be used only for manual migration.

File names with carriage returns or non-UTF-8 characters: transparent cloud tiering does not perform any migration or recall operation on files whose names include carriage returns or non-UTF-8 characters.
File systems mounted with the nodev option: If a file system is mounted with the nodev option, then it cannot be mounted to a directory with an existing folder with the same name as the file system. transparent cloud tiering is not supported in this situation.

Administrator cannot add a container pair set while managing a file system with 'automount' setting turned on.: Make sure that automount setting is not turned on while a file system is in use with transparent cloud tiering.

Files created through NFS clients when migrated to the cloud storage tier: If caching is turned on the NFS clients (with the --noac option) while mounting the file system, files that are migrated to the cloud storage tier remain in the co-resident status, instead of the non-resident status.

transparent cloud tiering configured with proxy servers: IBM® Security Key Lifecycle Manager does not work when transparent cloud tiering is configured with proxy servers.

Swift Dynamic Large Objects: transparent cloud tiering supports Swift Dynamic Large Objects only.

No support for file systems earlier than 4.2.x: cloud services support IBM Storage Scale file systems versions 4.2.x and later only.

Running reconciliation during heavy writes and reads on the file system: Reconciliation fails when it is run during heavy I/O operations on the file system.

For current limitations and restrictions, see IBM Storage Scale FAQs.

For information on interoperability of transparent cloud tiering with other IBM Storage Scale features, see Interoperability of transparent cloud tiering with other IBM Storage Scale features.