{"id":13508219,"url":"https://github.com/dm-vdo/kvdo","last_synced_at":"2025-04-12T17:46:05.122Z","repository":{"id":37549798,"uuid":"107871502","full_name":"dm-vdo/kvdo","owner":"dm-vdo","description":"A kernel module which provide a pool of deduplicated and/or compressed block storage.","archived":false,"fork":false,"pushed_at":"2025-01-24T01:07:37.000Z","size":8594,"stargazers_count":243,"open_issues_count":21,"forks_count":46,"subscribers_count":35,"default_branch":"master","last_synced_at":"2025-04-03T20:11:21.415Z","etag":null,"topics":["compression","deduplication","kernel-modules","linux-kernel","storage","vdo"],"latest_commit_sha":null,"homepage":"","language":"C","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"gpl-2.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/dm-vdo.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"COPYING","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2017-10-22T14:08:17.000Z","updated_at":"2025-01-24T01:05:24.000Z","dependencies_parsed_at":"2024-06-04T03:04:17.769Z","dependency_job_id":"e2057be4-1281-48ed-866e-eb4ee2794da8","html_url":"https://github.com/dm-vdo/kvdo","commit_stats":{"total_commits":51,"total_committers":4,"mean_commits":12.75,"dds":"0.17647058823529416","last_synced_commit":"e58f053ed24c46e72c5b7ad7ff029d50c11e7dc3"},"previous_names":[],"tags_count":78,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dm-vdo%2Fkvdo","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dm-vdo%2Fkvdo/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dm-vdo%2Fkvdo/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dm-vdo%2Fkvdo/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/dm-vdo","download_url":"https://codeload.github.com/dm-vdo/kvdo/tar.gz/refs/heads/master","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":248609619,"owners_count":21132916,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["compression","deduplication","kernel-modules","linux-kernel","storage","vdo"],"created_at":"2024-08-01T02:00:49.926Z","updated_at":"2025-04-12T17:46:05.102Z","avatar_url":"https://github.com/dm-vdo.png","language":"C","funding_links":[],"categories":["C","others"],"sub_categories":[],"readme":"# kvdo\n\nThe kernel module component of VDO which provides pools of deduplicated and/or\ncompressed block storage.\n\n## Background\n\nVDO is a device-mapper target that provides inline block-level deduplication,\ncompression, and thin provisioning capabilities for primary storage. VDO\nis managed through LVM and can be integrated into any existing storage stack.\n\nDeduplication is a technique for reducing the consumption of storage resources\nby eliminating multiple copies of duplicate blocks. Compression takes the\nindividual unique blocks and shrinks them with coding algorithms; these reduced\nblocks are then efficiently packed together into physical blocks. Thin\nprovisioning manages the mapping from logical block addresses presented by VDO\nto where the data has actually been stored, and also eliminates any blocks of\nall zeroes.\n\nWith deduplication, instead of writing the same data more than once each\nduplicate block is detected and recorded as a reference to the original\nblock. VDO maintains a mapping from logical block addresses (presented to the\nstorage layer above VDO) to physical block addresses on the storage layer\nunder VDO. After deduplication, multiple logical block addresses may be mapped\nto the same physical block address; these are called shared blocks and are\nreference-counted by the software.\n\nWith VDO's compression, blocks are compressed with the fast LZ4 algorithm, and\ncollected together where possible so that multiple compressed blocks fit within\na single 4 KB block on the underlying storage. Each logical block address is\nmapped to a physical block address and an index within it for the desired\ncompressed data. All compressed blocks are individually reference-counted for\ncorrectness.\n\nBlock sharing and block compression are invisible to applications using the\nstorage, which read and write blocks as they would if VDO were not present.\nWhen a shared block is overwritten, a new physical block is allocated for\nstoring the new block data to ensure that other logical block addresses that\nare mapped to the shared physical block are not modified.\n\nThis repository includes the kvdo module, which can be built and loaded as an\nout-of-tree kernel module. This module implements fine-grained storage\nvirtualization, thin provisioning, block sharing, compression, and\nmemory-efficient duplicate identification.\n\n## History\n\nVDO was originally developed by Permabit Technology Corp. as a proprietary set\nof kernel modules and userspace tools. This software and technology has been\nacquired by Red Hat and relicensed under the GPL (v2 or later). The kernel\nmodule has been merged into the upstream Linux kernel as the dm-vdo devive\nmapper target. The source for this module can be found in drivers/md/dm-vdo/.\n\n## Documentation\n\n- [RHEL9 VDO Documentation](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/deduplicating_and_compressing_logical_volumes_on_rhel/index)\n- [RHEL8 VDO Documentation](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/deduplicating_and_compressing_storage/index)\n- [RHEL7 VDO Integration Guide](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/storage_administration_guide/vdo-integration)\n- [RHEL7 VDO Evaluation Guide](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/storage_administration_guide/vdo-evaluation)\n\n## Releases\n\n**This repository is no longer being updated for newer kernels.**\n\nThe most recent version of this project can be found in the upstream Linux\nkernel, as the dm-vdo module. Each existing branch of this repository is\nintended to work with a specific release of Enterprise Linux (Red Hat\nEnterprise Linux, CentOS, etc.).\n\nVersion | Intended Enterprise Linux Release\n------- | ---------------------------------\n6.1.x.x | EL7 (3.10.0-*.el7)\n6.2.x.x | EL8 (4.18.0-*.el8)\n8.2.x.x | EL9 (5.14.0-*.el9)\n\n* Pre-built versions with the required modifications for older Fedora releases\n  can be found [here](https://copr.fedorainfracloud.org/coprs/rhawalsh/dm-vdo)\n  and can be used by running `dnf copr enable rhawalsh/dm-vdo`.\n\n## Upgrades\n\nThe latest version of this project is available in the Linux kernel as the\ndm-vdo module starting in version 6.9. If you have a VDO volume created with\nthe kvdo module, be sure to shut it down cleanly before switching to the\ndm-vdo module. Failure to do so may result in issues including loss of data.\n\nAs with any upgrade, it is advisable to create a snapshot of the device before\nupgrading to the new module.\n\n## Building\n\nIn order to build the kernel modules, invoke the following command\nfrom the top directory of this tree:\n\n        make -C /usr/src/kernels/`uname -r` M=`pwd`\n\nTo install the compiled module:\n\n        make -C /usr/src/kernels/`uname -r` M=`pwd` modules_install\n\n* There is a dkms.conf template that can be used in the kvdo.spec file which\n  can take care of rebuilding and installing the kernel module any time a new\n  kernel is booted.\n\n* Patched sources that work with certain older upstream kernels can be found\n  [here](https://github.com/rhawalsh/kvdo).\n\n## Communication Channels and Contributions\n\nCommunity feedback, participation and patches are welcome to the\n[vdo-devel](https://github.com/dm-vdo/vdo-devel) repository, which is the\nparent of this one. This repository does not accept pull requests.\n\n## Licensing\n\n[GPL v2.0 or later](https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html).\nAll contributions retain ownership by their original author, but must also\nbe licensed under the GPL 2.0 or later to be merged.\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdm-vdo%2Fkvdo","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fdm-vdo%2Fkvdo","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdm-vdo%2Fkvdo/lists"}