HECToR External Filesystem Upgrade: Timeline

Please note that this timeline is currently being reviewed. The final dates will be communicated to users once the review has been completed.

In order to increase the amount of '/work' disk space available to users and to increase the flexibility of the HECToR service we are planning to upgrade the system over the next few months.

We will, of course, endeavour to minimise the impact to the HECToR service but there is the chance that this work may impact the work of some users.

Please find below a proposed time line for the upgrade work and a summary of what is being done and the benefits to all HECToR users once the work has been completed.

Proposed Time Line

This is our current working plan. The most up to date list of maintenance sessions can be found on the HECToR User Wiki (use your SAFE details to log in) at:

https://wiki.hector.ac.uk/userwiki/Category:Maintenance

and we recommend that users use this page as their primary source of information for upcoming HECToR work. We will keep you informed of changes via the HECToR mailing list but the page above will always have the definitive plan.

  • 28 July 2010 - Phase 2a Maintenance 12:00-18:00 - Operating system patch installation, configure external filesystem
  • 4 August 2010 - Phase 2b Maintenance 12:00-18:00 - Operating system patch installation
  • 11 August 2010 - Possible Phase 2a Maintenance 12:00-18:00
  • 18 August 2010 - Phase 2a and Phase 2b Maintenance 12:00-18:00 - Power work at installation site
  • 25 August 2010 - Phase 2a Maintenance 08:00-20:00 - Migration of majority of phase 2a /work user data to external filesystem
  • 26 August 2010 - 14 September 2010 - Migration of remaining phase 2a /work user data to external filesystem
  • 15 September 2010 - Phase 2b Maintenance (12:00-18:00) - Attach external filesystem to phase 2b
  • 16 September 2010 - 21 September 2010 - Migration of phase 2b /work user data to external filesystem
  • 13 October 2010 - Full 1188 TB of external /work filesystem available to users

What is happening?

In order to increase the amount of high-performance, parallel filesystem (also known as /work) available to HECToR users and to ensure that the same filesystem is visible from both the phase 2a and phase 2b services we are installing an external, high-performance, parallel filesystem.

The diagram below shows the current HECToR filesystem layout with two internal /work filesystems:

Filesystem layout before upgrade

and this diagram illustrates the layout once the upgrade is completed (with one, shared, external /work filesystem):

Filesystem layout after upgrade

Once the filesystem has been installed and attached to the phase 2a system we will migrate all the data currently on the internal phase 2a /work filesystem to the external disks. In order to avoid an extensive amount of downtime for all users, this work will be phased project by project depending on the volume of data on /work. We estimate that 94% of projects will be covered in a single maintenance slot (currently scheduled for 25 August).

The remaining 6% will be handled on a case by case basis (between 26 August and 14 September) due to the large volumes of data held. We will be contacting all PIs to advise when your project will be affected and to let you know how this will impact your users. This work will involve a period of time where quota changes via SAFE will be unavailable. Updated disk usage reports will also be unavailable while the process of copying data is ongoing. Temporary work space will also be available on the new filesystem (which projects can use while original data is being copied) and we will issue full instructions on how to use it.

In advance of this, if you are currently keeping data on /work which you do not require, please delete it. If you have data which can be archived, please do so. If your project does not currently have an archive quota and you have data to archive, please contact the helpdesk and we will set this up for you. By phasing the work project by project we are doing our best to limit the impact of this change, but the less data there is, the quicker the process will be.

Why are we doing this?

This upgrade provides a number of benefits to HECToR users:

  • an increased amount of high-performance disk space;
  • /work will be shared by both the phase 2a and phase 2b systems so that it is simple to use either system without copying data across the network;
  • files on /work will usually remain available through maintenance sessions (unless both phase 2a and phase 2b services are unavailable);
  • flexibility to attach additional user services to the external filesystem (for example, specialist compute hardware).
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