{
    "mode": "man",
    "parameter": "cache_metadata_size",
    "section": "8",
    "url": "https://www.chedong.com/phpMan.php/man/cache_metadata_size/8/json",
    "generated": "2026-05-30T07:08:47Z",
    "synopsis": "cachemetadatasize [options]",
    "sections": {
        "NAME": {
            "content": "cachemetadatasize  - Estimate the size of the metadata device needed for a given configura‐\ntion.\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "cachemetadatasize [options]\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "cachemetadatasize estimates the size of the metadata.\nEither --nr-blocks, or --block-size and --device-size must be specified.\n",
            "subsections": []
        },
        "OPTIONS": {
            "content": "",
            "subsections": [
                {
                    "name": "--nr-blocks {natural}",
                    "content": "Specify the number of cache blocks.\n",
                    "long": "--nr-blocks"
                },
                {
                    "name": "--block-size {sectors}",
                    "content": "Specify the size of each cache block in 512 byte sectors.\n",
                    "long": "--block-size"
                },
                {
                    "name": "--device-size {sectors}",
                    "content": "Specify total size of the fast device used in the cache.  In 512 byte sectors.\n",
                    "long": "--device-size"
                },
                {
                    "name": "--max-hint-width {nr bytes}",
                    "content": "Specify hint width.\n\nCache policies use a per block 'hint' to record extra info (for instance\nhit counts).  At the moment all policies use a 4 byte hint\nwidth.  If you want to use a different hint width specify it with this\nswitch.\n\n",
                    "long": "--max-hint-width"
                }
            ]
        },
        "EXAMPLE": {
            "content": "$ cachemetadatasize --nr-blocks 10240\n\n$ cachemetadatasize --block-size 128 --device-size 1024000\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "cachedump(8), cacherepair(8), cacherestore(8)\n",
            "subsections": []
        },
        "AUTHOR": {
            "content": "Joe Thornber <ejt@redhat.com>, Heinz Mauelshagen <heinzm@redhat.com>\n\n\n\nSystem Manager's Manual                  Device Mapper Tools                  cachemetadatasize(8)",
            "subsections": []
        }
    },
    "summary": "cachemetadatasize  - Estimate the size of the metadata device needed for a given configura‐ tion.",
    "flags": [
        {
            "flag": "",
            "long": "--nr-blocks",
            "arg": null,
            "description": "Specify the number of cache blocks."
        },
        {
            "flag": "",
            "long": "--block-size",
            "arg": null,
            "description": "Specify the size of each cache block in 512 byte sectors."
        },
        {
            "flag": "",
            "long": "--device-size",
            "arg": null,
            "description": "Specify total size of the fast device used in the cache. In 512 byte sectors."
        },
        {
            "flag": "",
            "long": "--max-hint-width",
            "arg": null,
            "description": "Specify hint width. Cache policies use a per block 'hint' to record extra info (for instance hit counts). At the moment all policies use a 4 byte hint width. If you want to use a different hint width specify it with this switch."
        }
    ],
    "examples": [
        "$ cachemetadatasize --nr-blocks 10240",
        "$ cachemetadatasize --block-size 128 --device-size 1024000"
    ],
    "see_also": [
        {
            "name": "cachedump",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/cachedump/8/json"
        },
        {
            "name": "cacherepair",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/cacherepair/8/json"
        },
        {
            "name": "cacherestore",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/cacherestore/8/json"
        }
    ]
}