diff options
Diffstat (limited to 'man')
| -rw-r--r-- | man/man5/zfs-module-parameters.5 | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index d3aa2e6b0..2f87f114c 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -699,6 +699,43 @@ Default value: \fB1\fR. .sp .ne 2 .na +\fBzfs_free_leak_on_eio\fR (int) +.ad +.RS 12n +If destroy encounters an EIO while reading metadata (e.g. indirect +blocks), space referenced by the missing metadata can not be freed. +Normally this causes the background destroy to become "stalled", as +it is unable to make forward progress. While in this stalled state, +all remaining space to free from the error-encountering filesystem is +"temporarily leaked". Set this flag to cause it to ignore the EIO, +permanently leak the space from indirect blocks that can not be read, +and continue to free everything else that it can. + +The default, "stalling" behavior is useful if the storage partially +fails (i.e. some but not all i/os fail), and then later recovers. In +this case, we will be able to continue pool operations while it is +partially failed, and when it recovers, we can continue to free the +space, with no leaks. However, note that this case is actually +fairly rare. + +Typically pools either (a) fail completely (but perhaps temporarily, +e.g. a top-level vdev going offline), or (b) have localized, +permanent errors (e.g. disk returns the wrong data due to bit flip or +firmware bug). In case (a), this setting does not matter because the +pool will be suspended and the sync thread will not be able to make +forward progress regardless. In case (b), because the error is +permanent, the best we can do is leak the minimum amount of space, +which is what setting this flag will do. Therefore, it is reasonable +for this flag to normally be set, but we chose the more conservative +approach of not setting it, so that there is no possibility of +leaking space in the "partial temporary" failure case. +.sp +Default value: \fB0\fR. +.RE + +.sp +.ne 2 +.na \fBzfs_free_min_time_ms\fR (int) .ad .RS 12n |