Managing Your Backups

1. Introduction

This page gives background practical information about running your backups, from your initial backup through to the regular backups that keep the HFS copy of your files up-to-date. We recommend that you read it before running your first TSM backup.

2. Initial backup

Your initial backup of a machine newly registered to the HFS should ideally be:

  • a manual, not a scheduled, backup;
  • a backup of local disk drives and partitions only, not of network or DVD drives; and
  • a backup of no more than the daily limit (200GB for desktops/laptops; 400GB for servers; 500GB for large servers).

Your initial manual backup may well be a full backup of your entire local filestore, depending on what you select in TSM and on how much data there is to be sent. With disk capacity in a typical personal computer ranging from 500GB upwards, and with that of departmental and college servers being many times larger, this can mean that your initial backup requirements are very large. Network transfer rates vary: approximate maximum speeds are 30GB/hour on a 100Mb network and 300GB/hour on a 1Gb network, but such a speed can be reduced greatly by other factors such as other traffic on your local network and the speed of your machine's disk(s). Please try to estimate and allow sufficient time for this initial backup to complete while you are in attendance. We require servers to have a connection speed of at least 1Gb.

If you select the whole of your machine for backup, by default TSM will back up all the files, though there are a few exceptions - for these please see our policy page on files and folders excluded from backup. You can exclude further files, folders and drives from backup so that TSM does not back them up - please see our page on how to exclude files, folders and drives from backup for how to do this.

If the total amount of data does not exceed 200GB (for desktops/laptops), 400GB (for servers) or 500GB (for large servers), then you will be able to send all your data within a single backup session.

If you attempt to send an amount of data exceeding the daily limit then your initial session will be stopped when that limit is reached, and the TSM backup account will be locked. Newly registered clients have a grace period during which the TSM account is unlocked automatically, usually the next day: the period for desktops/laptops is 14 days of grace unlocks, and that for servers is 28 days. (For times when automatic unlocks occur, please see our FAQ item My node is locked - when can it be unlocked?) This is to allow completion of the initial backup. Once this period is over, the lockout is effective until you contact us.

If, therefore, you have an amount of data exceeding the daily limit which you wish to backup, then your initial backup will need to be staged - that is, spread over a number of days. On this please see the next section, 3. Subsequent backups.

3. Subsequent backups

If your first backup did not result in all your data being sent to the HFS, because it was cut off when the daily limit was reached, then the second backup will pick up from the point at which the earlier session was stopped. If you have a very large amount of data to send, you may need to continue in this manner for several days before your initial backup is completed.

Once this is done, subsequent sessions will only back up files which are new or have changed since the last time, because HFS backups work on the principle of incremental forever. The server and the client (user) machine compare lists of which files are on the client and which are already backed up to the HFS, to allow a full reconciliation to take place. The server passes full details of the client's filestore to the client and the client compares this with the current filestore; any new or changed files are then backed up. A file is considered to have changed if any one of a series of properties have changed: size, permissions, owner, modification date/time. The client tells the server which files have been deleted since the last backup; the server then marks the backup copies for deletion. (On how long these are kept for, please see our FAQ item How long do you keep data for?)

If you selected only certain files, folders or drives during your manual backups, please note that your selection will not be saved by TSM for future manual or scheduled backup sessions. If you wish for certain items not to be included in your scheduled backups, please see our section on how to exclude files and folders from backup.

Once your initial backup is completed, subsequent backups can be performed manually, but our recommendation is to use the automated scheduled backup facilities and to supplement these with manual backups when required. The exception to this is for remote machines that always backup over VPN. As you have to make a VPN connection in order to back up these need to be backed up manually.

4. Running manual backups

To run a manual backup, please see our instructions on doing so for Windows, Mac, Solaris and Linux. For how to back up on the command line, see using the TSM client command line interface.

Written by IT Services. Latest revision 4 March 2016