This document provides an overview of the current recommendations and requirements for administering a preservation cache for the [PLN], including staffing and hardware. This document was last revised by the Technical Committee in [year].

Our Member institutions have identified three key roles that they assign to their local staff members in order to effectively run their caches and prepare their content for ingest into the [PLN] Preservation Network: cache administration, plugin development, and data wrangling. It is possible that a single technical staff member may be responsible for one or more of these roles. For example, the staff member assigned to plugin development and data wrangling may be the same person (if not they should, if possible, work closely together). The [PLN] Central staff provides training for these roles as requested. The anticipated time commitments, skill-sets, and common tasks, as based on current Member experiences, are documented below.

[PLN] recommends that at least two people from each member organization have SSH access to their LOCKSS cache.

Time required	Between 2-10 hrs/mo (average 5 hrs/mo)
Required skills	Basic level administration of UNIX-based platforms; ability to run and maintain servers, proxy servers, firewalls; ability to mount network storage or configure local RAID.
Helpful skills	Knowledge or experience in digital libraries or library IT.
Common tasks	Installing a [PLN] LOCKSS cache; assisting with content ingest; performing updates for the cache; monitoring the cache; documenting procedures.

Members that will be packaging and ingesting their content as BagIt bags will be able to use a generic bagit plugin that will require no additional development time or activity. Members who wish to directly integrate digital repositories and the [PLN] LOCKSS network will need to write custom LOCKSS plugins.

Time required	Between 2-25 hrs on 1st plugin (average 15 hrs) Between 1-6 hrs on additional plugins (average 3 hrs)
Required skills	Familiarity with XML; familiarity with file structuring on widely used platforms (Windows/Unix/Linux); understanding of regular expressions; solid understanding of web technologies (e.g., browsers and plugins).
Helpful skills	Familiarity with metadata standards; programming experience.
Common tasks	Writing/testing plugins.

Time required	Between 15-40 hrs per collection (depends on existing repository solution).
Required skills	Familiarity with file structuring on widely used platforms (Windows/Unix/Linux); basic understanding of web technologies (e.g., web servers).
Helpful skills	Experience with re-formatting digital content and media; experience with archival appraisal and selection methods; familiarity with metadata standards and cataloging; programming experience; database management; experience using tools to create bagit bag packages.
Common tasks	Creating manifest pages; renaming and resizing files; preparing web servers to deliver content; creating collection level metadata.

Member system administrators (or designated technical staff members) should have ready access and authorizations to access their [PLN] LOCKSS caches to the fullest extent possible.

Member system administrators (or designated technical staff members) should have the ability to effectively coordinate with staff members that are responsible for configuring institutional firewalls to allow [PLN] LOCKSS caches to participate in the [PLN] Preservation Network.

Members opting to host caches must purchase hardware, or utilize local IT services for server hosting, that meet the specifications below to operate a [PLN] LOCKSS cache.

Member institutions must be prepared to adequately staff the necessary roles (see Skills Recommendations above) to implement and maintain a [PLN] LOCKSS cache throughout the period of their membership.

Members opting to host caches must agree to purchase and maintain the necessary technical hardware (as described below, either physical or virtual) required to operate a [PLN] LOCKSS cache throughout their membership period.

The above Members also agree to update their technical hardware on a five-year cycle using the current [PLN] Technical Specifications. This ensures that all of the [PLN] Preservation Network’s infrastructure is replaced in a manner consistent with industry best practices. This rolling cycle also enables the [PLN] to avoid network-wide uniformity of technical hardware. The five-year cycle applies to both physical and virtual servers.

[PLN] members hosting caches agree to either repurpose their technical hardware for the [PLN] test network when it has reached its five-year cycle (as long as it still functions) or to host a virtual server for the same purpose. Storage requirements for test caches are 500 GB. Caches re-purposed for the [PLN] test network will not be subjected to any recovery actions in the event of disk failures. If a member has retired more than one cache, only its most recently retired cache should be part of the test network; older caches may be repurposed as needed by the member for other functions.

In the case of catastrophic circumstances, Members have the ability to request technical and financial assistance with the restoration of a preservation site’s caches, software, and collections by the [PLN]. These requests will be reviewed and, at the discretion of the Leadership Team, in coordination with the Membership, either approved or denied.

Members may use either virtual or physical server hardware. All LOCKSS caches should be physically secured (physical servers and virtual server infrastructure), accessible only to appropriate staff members, and appropriately climate controlled. [PLN] members are recommended to work with Central Staff and LOCKSS Support on deploying new caches.

• 4 processors for virtual servers; Intel Core i7 or better processor with at least 4 cores if physical server

  • 8 GB RAM

• RHEL 7, CENTOS 7, ; RHEL 8, Rocky Linux 8 (minimal install group recommended)

• CENTOS 8 is NOT recommended.

• Root-level (administrative) access is required to execute the [PLN] integration script

Members may use network or locally attached storage to provision 40 TB of RAID protected storage. If the network reaches full capacity, members may be asked to provision additional RAID protected storage.

40 TB. While 40 TB is required, members may choose to scale up to that amount over time; when doing this, members must provision 12 TB to start and increase over time to reach 40 TB.

40 TB RAID protected storage (RAID6 recommended). RAID6 requires two hard drives for parity. For example, if using 8-TB hard drives, seven are required (56 TB raw) to meet 40 TB requirement.

Only the system administrators who need to maintain the server should have user accounts; these accounts should have strong passwords. It’s recommended to disable root logins if possible. Security patches should be applied promptly, following local site security update policies. One way this can be achieved is by using yum-cron.

LOCKSS caches in the [PLN] network require a dedicated IP address that is routable from the Internet and can accept inbound connections from the internet. NAT is supported.

A firewall should be used to block access to all unused ports. Some ports are required to be open for communication in the [PLN] network. LOCKSS requires certain inbound TCP ports to be open, outbound connections to all ports should be allowed.See the [[PLN] Technical Specifications, Firewall and Port Settings] for full details.