# MinIO Server Limits Per Tenant

For optimal production setup MinIO recommends Linux kernel version 4.x and later.

## Erasure Code (Multiple Drives / Servers)

| Item                                                            | Specification |
|:----------------------------------------------------------------|:--------------|
| Maximum number of servers per cluster                           | no-limit      |

   *       then sequentially accessing it could result in other processes dying. This is solvable
   *       via madvise(2), but that obviously doesn't exist in java.
   *   <li>Ordinary copy. Kernel copies bytes into a kernel buffer, from a kernel buffer into a
   *       userspace buffer (byte[] or ByteBuffer), then copies them from that buffer into the
   *       destination channel.
   * </ol>
   *

issues with Docker 1.9.1 can be found below.
  * CPU hardcapping will be enabled by default for containers with CPU limit set,
if supported by the kernel. You should either adjust your CPU limit, or set CPU
request only, if you want to avoid hardcapping. If the kernel does not support
CPU Quota, NodeStatus will contain a warning indicating that CPU Limits cannot
be enforced.

	stats, err := readStat(statsFile)
	if err != nil {
		return IOStats{}, err
	}
	if len(stats) < 11 {
		return IOStats{}, fmt.Errorf("found invalid format while reading %v", statsFile)
	}
	// refer https://www.kernel.org/doc/Documentation/block/stat.txt
	iostats = IOStats{
		ReadIOs:      stats[0],
		ReadMerges:   stats[1],
		ReadSectors:  stats[2],
		ReadTicks:    stats[3],
		WriteIOs:     stats[4],

      - name: Enable KVM group perms
        # https://github.blog/changelog/2023-02-23-hardware-accelerated-android-virtualization-on-actions-windows-and-linux-larger-hosted-runners/
        run: |
          echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' | sudo tee /etc/udev/rules.d/99-kvm4all.rules
          sudo udevadm control --reload-rules
          sudo udevadm trigger --name-match=kvm

		_ = setMaxResources(globalServerCtxt)
	})

	// Verify kernel release and version.
	if oldLinux() {
		warnings = append(warnings, color.YellowBold("Detected Linux kernel version older than 4.0 release, there are some known potential performance problems with this kernel version. MinIO recommends a minimum of 4.x linux kernel version for best performance"))
	}

	maxProcs := runtime.GOMAXPROCS(0)

func fixLongPath(path string) string {
	// Do nothing (and don't allocate) if the path is "short".
	// Empirically (at least on the Windows Server 2013 builder),
	// the kernel is arbitrarily okay with < 248 bytes. That
	// matches what the docs above say:
	// "When using an API to create a directory, the specified
	// path cannot be so long that you cannot append an 8.3 file

# Only include debug info for files under tensorflow/, excluding kernels, to
# reduce the size of the debug info in the binary. This is because if the debug
# sections in the ELF binary are too large, errors can occur. See
# https://github.com/tensorflow/tensorflow/issues/48919.
# Users can still include debug info for a specific kernel, e.g. with:
#     --config=dbg --per_file_copt=+tensorflow/core/kernels/identity_op.*@-g

	if err != nil {
		buf, err = os.ReadFile(cgroupV1MemLimitFile)
	}
	if err != nil {
		return 0
	}
	limit, err = strconv.ParseUint(strings.TrimSpace(string(buf)), 10, 64)
	if err != nil {
		// The kernel can return valid but non integer values
		// but still, no need to interpret more
		return 0
	}
	if limit >= 100*humanize.TiByte {
		// No limit set, or unreasonably high. Ignore
		return 0
	}
	return limit
}

| `minio_node_scanner_versions_scanned`      | Total number of object versions scanned since server start. |
| `minio_node_syscall_read_total`            | Total read SysCalls to the kernel. /proc/[pid]/io syscr.    |
| `minio_node_syscall_write_total`           | Total write SysCalls to the kernel. /proc/[pid]/io syscw.   |
| `minio_usage_last_activity_nano_seconds`   | Time elapsed (in nano seconds) since last scan activity.    |

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