Further Information on the HFS Backup Service
1. The HFS and TSM
The HFS (Hierarchical File Server) is an Oxford University centrally funded service providing data backup and long-term archive services to senior members, postgraduates and staff.
The HFS is widely and extensively used throughout Oxford. In the 7 days up to 2012-May-16, 4496 clients accessed the backup and archive servers in 22427 sessions, sending 60.6 million files and 68.7 TB of data. In total the backup and archive servers currently hold billion files and TB of data.
We welcome any comments or suggestions about the service using our feedback form.
This page gives a general overview of the HFS service, comprising information on: how the HFS works; limits to the service; registering for the service and installing TSM; backing up; and what to do if you leave or will be away for an extended period.
2. How it works
Your data is sent from your computer, across the university network to the HFS servers and is then ultimately stored on magnetic tape in an automated (robotic) tape library. Our servers and tape library are situated in a climate-controlled, secure location. Three copies of your data are made, each to separate tapes: one copy is held in the automated tape library while two copies are stored in separately located fire-proof safes. Access to the data is private to the owner and is normally available 24 hours a day, seven days a week.
The HFS 3494 tape library was purchased in 1995. It has grown with demand and now spans ten frames containing 24 TS1120 tape drives and around 3300 slots for 3592-type tape cartridges. The latter comprise half-inch tape with an in-the-field capacity of about 1TB per volume, although this may change with future generations of tape drive. The library permanently holds one copy of all data sent to the HFS and therefore has an effective capacity of 3PB (three petabytes).
3. Limits to the service
3.1. Service availability
Generally, the HFS service is available 24/7. However, as with all systems there is from time to time a requirement to update the software and device firmware that underpins the service. Where this requires limiting access to some or all elements of the HFS Service, such interruptions will be advertised to the itss-announce maillist and on the OUCS Status page, where real-time availability of all OUCS services can be checked.
3.2. Guidelines for acceptable use
The HFS is a much-used, vital service but as with all university services, resources are limited. In order to provide a level of service that is fair to all users, we require that users follow our guidelines for acceptable use of HFS backup services.
3.3. Connect via the university network, wireless or VPN
By far the best backup/restore and archive/retrieve speeds are available if you use a wired connection to the university network. You may also back up over wireless (only via eduroam, not OWL-VPN). The HFS is also currently trialing a VPN-based backup service for people not based in Oxford.
3.4. What data is backed up?
The HFS backup service is for data backups only and should not be used to attempt a full
system recovery. In order to reduce backup times and failures there are a
number of files/folders excluded from the backup process, e.g. the
Windows and Program Files folder on a
Microsoft Windows machine. Please see further our page on
files and folders excluded from backup.
3.5. Data retention
The HFS backup service is intended to secure your current work and consequently, a maximum of two versions of any particular file on your local system are kept: the current version and the penultimate version (backed up before the current version was created).
Please note that, in both cases, the maximum retention only comes into operation after the file has been deleted from the local disk.
Large server backup policy is the same as that of the server backup service except that, in addition, each client's data is consolidated onto the minimum number of online tape volumes. This allows considerably speedier restore of data for machines with a large backup filestore.
4. Registering to use the HFS for backup or archive
4.1. The registration and installation process
To be able to back up or archive your data, you need to register with the HFS and then install TSM (Tivoli Storage Manager) on your computer. You need to be a university staff member or postgraduate with an Oxford username and password. To open a backup account with the HFS, please follow the links at our page on getting started with TSM backups. For the archive service, please see using the TSM client software for archive & retrieve.
4.2. Nodenames
5. Backing up
5.1. The initial backup
Once you have registered and installed your backup software, but before you run a manual backup, consider what you want to back up. By default, the TSM software will back up all the data on your machine and its locally attached (e.g. USB drives), bar our default exclusions (see 3.4. What data is backed up? above). However, in many cases this is a waste: in the event of complete failure of your machine, you would restore most of your machine from the original installation DVD or CDs. Please see further our page on how to exclude files, folders and drives from backup: if you wish only to backup and secure your own data, you can do so easily by following the instructions to back up only the personal user area; or you can restrict and target your backups by excluding specific files, folders and specific drives.
Please only backup local disks on your machine: do not back up shared network drives, NFS or otherwise remote-mounted drives. If you routinely connect up removable drives (such as USB or FireWire) or memory sticks which you do not wish to include in your backup, please consider excluding these from backup.
Your initial manual backup may be a full backup of your entire local filestore. This can mean your initial backup exceeds the daily limit of 100GB (for desktops/laptops) or 200GB (for small/medium servers). We have procedures in place that detect this. The backup session will automatically be cancelled and newly registered clients will be locked out until 10:00 on the next working day (14:00 for servers); we allow 14 days after registration to complete the initial backup in this way, after which time the lockout is effective permanently until you contact us. When the next backup session is started, the backup carries on from the point at which it was stopped.
5.2. Subsequent backups
After your initial backup, you may choose to use manual backups, or scheduled backups, or both. It does not matter which: you will be automatically registered for overnight scheduled backups (once a week for destkops/laptops, six times a week for servers), but you do not have to use them. For the security of your data, we recommend that you back up at least once a week.
TSM views any change in the name, size, date, permissions or path of a file as a reason to back it up again. Therefore, please try to avoid renaming top-level directories or performing wholesale permission changes or large-scale movements of data from one area to another, as these will occasion a fresh, duplicate, backup of your data. Where such modifications are foreseen as necessary, please contact hfs@ox.ac.uk as we may be able to avoid the otherwise resultant duplication.
If you have renamed, moved or deleted a whole partition, please help us free up resources by contacting hfs@ox.ac.uk when you no longer require that backup.
6. If you stop using the HFS, temporarily or permanently
The HFS backup service provides a service to active clients. If you are leaving Oxford, or no longer require use of the HFS Service, please help us and deregister your backup account and uninstall the TSM software. This helps us free up storage space and saves a small amount on the licence fee for the software.
If you are leaving Oxford temporarily and will not be backing up regularly, contact the Help Centre to let us know when you are away and we will arrange to keep your backups until you return.
In order to manage the system efficiently, the HFS Team will remove any client and its data that has not backed up for 90 days or more, and any individual partitions that have not been backed up for 90 days or more.
Before doing so, we will attempt to contact the registered owner of the machine but, failing a reply, we will remove both data and machine registration, where necessary, from the backup service.
Please perform regular regular (at least weekly) backups of your data. This protects your work and can be conveniently achieved via the overnight scheduled backup service.
