1. A method executed by a computer of providing a data store, comprising: storing, by the computer, nodes representing respective chunks of files in a predefined structure that defines relationships among the nodes, wherein the files are divided into the chunks; collecting, by the computer, the nodes into plural groups stored in persistent storage, wherein some of the nodes are collected into a particular one of the groups according to a locality relationship of the some of the nodes, wherein each of the groups has a header portion and a data portion, the data portion containing payload data of respective chunks associated with the corresponding group, and the header portion containing hashes of the chunks associated with the corresponding group, wherein each of the hashes is calculated by applying a hash function on content of a corresponding one of the chunks in the corresponding group; associating location indications with the nodes, wherein the location indication of a first one of the nodes includes a pending indication to indicate that the first node has not yet been written to a group in the persistent storage, and wherein the location indication of a second one of the nodes includes an indication of a group in the persistent storage that the second node is part of; and loading one or more of the groups from the persistent storage into temporary storage to enable read operations with respect to chunks of files, wherein the groups comprise pages in the persistent storage, wherein loading the one or more of the pages into the temporary storage comprises loading the respective one or more header portions of the one or more pages into the temporary storage without loading the respective one or more data portions.