The HFS is a valuable University resource with a large but ultimately finite capacity. Certain guidelines are therefore required to ensure the fair use of its resources so that the facility can be used as widely as possible.
We constantly review our operational limits in the light of available resources and capabilities. Currently we recommend a single backup account store no more than 10TB of data. Independent of the amount of data stored, where a large number of files are held locally, we strongly recommend, and may insist, that these are either bundled into a local archive file prior to sending to the HFS or the local disk is re-partitioned into smaller filesystem/volume/drive partitions. There is no magic limit here, as the requirement for this depends partially on the client machine's own resources and ability to sort large numbers of files. Typically, the figure revolves around several million file objects in any one partition.
1. Connection speed to the HFS
Long slow backups can cause considerable problems with the service: they lock server resources that need to be spread across many clients. Consequently, we demand that clients upload data at a reasonable rate such that the upload of their data does not take an unreasonable amount of time. Should this not be attainable and a client session runs for many hours with little data uploaded, then the client session will be cancelled and locked. Where slow upload speeds are not due to transient factors (e.g. network misconfiguration) but are permanent (i.e. poor network bandwidth), access to the HFS service may be refused. Current limits are documented in our FAQ item How much data can I back up?. It should be noted that there is currently no maximum connection speed limit.
2. What to exclude from backups
The HFS backup service is intended for active data that is in use by current members of the University. Certain files types which should not be backed up are excluded from backup by the HFS set of default exclusions. However, these exclusions cannot catch all examples. Therefore we ask that users ensure that the following data are excluded from HFS Backup on all client machines they own or manage.
archive.pst: these are date-stamped by Outlook every time it is run, and therefore get needlessly resent by TSM on every backup. (As an alternative, backup of these files is permitted if you detach them from Outlook via
[Data File Management]. Please contact firstname.lastname@example.org if you wish to do this.)
Examples of how to exclude files and folders from HFS backups can be found in our page on how to exclude files and folders from backup. Further help can be obtained by contacting email@example.com.
3. Moving data around
The TSM software recognises a file moved to a new location on a system as a new file and thus a candidate for backup. A renamed mountpoint, drive, volume or partition will also, unless specifically excluded, occasion a fresh backup of all data on it. Windows drives derive their name from the Windows computer name, thus a change to this (which in itself might be due to a change in the machine's TCP/IP Name), can act as a partition rename. In these cases the data is in effect copied again and hence lies duplicate within the HFS Backup system. It is thus imperative that users avoid unnecessary moves and renames.
In cases where you do anticipate essential large-scale moves or renames of your local datastore, please contact firstname.lastname@example.org beforehand so that we may manage this.
Additionally, we may insist on local measures being implemented in order that the backup or archival of that data does not consume a large amount of (HFS) system resources. These local measures may include, but are not limited to:- excluding files, re-partitioning into smaller filesystem/volume/drive partitions or pre-processing files before backup or archive.