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| author | Dan Williams <dan.j.williams@intel.com> | 2008-07-19 02:14:44 +0200 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2008-07-19 02:14:44 +0200 |
| commit | a5ee6dfbf506424103d4de6579037836858bea72 (patch) | |
| tree | 6fe960359aed46187a4b4fa2ff8b6651a9c2bf99 /md.4 | |
| parent | msg: add a timeout to ping_monitor (diff) | |
| download | mdadm-a5ee6dfbf506424103d4de6579037836858bea72.tar.xz mdadm-a5ee6dfbf506424103d4de6579037836858bea72.zip | |
Document preread_bypass_threshold
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'md.4')
| -rw-r--r-- | md.4 | 9 |
1 files changed, 9 insertions, 0 deletions
@@ -530,6 +530,15 @@ all read and write operations to the array. The default is 128. Increasing this number can increase performance in some situations, at some cost in system memory. +.TP +.B md/preread_bypass_threshold +This is only available on RAID5 and RAID6. This variable sets the +number of times MD will service a full-stripe-write before servicing a +stripe that requires some "prereading". For fairness this defaults to +1. Setting this to 0 maximizes sequential-write throughput at the cost +of fairness to threads doing small or random writes. Valid values are 0 +to stripe_cache_size. + .SS KERNEL PARAMETERS |