1:29 p.m.
Gitweb:
http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=5e8f362c9eaae7...
Commit: 5e8f362c9eaae7bbcf69fd779d8c441f7de9042a
Parent: a164d603d386c5daed06b46316ef3c001807dff9
Author: David Teigland <teigland(a)redhat.com>
AuthorDate: Tue Jan 20 10:45:47 2015 -0600
Committer: David Teigland <teigland(a)redhat.com>
CommitterDate: Tue Jan 20 13:28:34 2015 -0600
lvmthin: include errorwhenfull
and don't display the size of pmspare to avoid setting an
expectation of a specific size.
---
man/lvmthin.7.in | 51 +++++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 45 insertions(+), 6 deletions(-)
diff --git a/man/lvmthin.7.in b/man/lvmthin.7.in
index 84a3138..b2db5a7 100644
--- a/man/lvmthin.7.in
+++ b/man/lvmthin.7.in
@@ -398,10 +398,10 @@ explicitly.
# lvconvert \-\-type thin\-pool \-\-poolmetadata vg/pool0meta vg/pool0
# lvs \-a
- [lvol0_pmspare] vg ewi------- 10.00g
- pool0 vg twi---tz-- 10.00g
- [pool0_tdata] vg Twi------- 10.00g
- [pool0_tmeta] vg ewi------- 1.00g
+ [lvol0_pmspare] vg ewi-------
+ pool0 vg twi---tz--
+ [pool0_tdata] vg Twi-------
+ [pool0_tmeta] vg ewi-------
.fi
The "Metadata check and repair" section describes the use of
@@ -715,8 +715,47 @@ For a 1G pool, using 700M will trigger a resize to 1.2G. When the
usage exceeds
\&
-If thin pool data space is exhausted, writes to thin LVs will be queued
-until the the data space is extended. Reading is still possible.
+When properly managed, thin pool data space should be extended before it
+is exhausted (see previous section). But, if thin pool data space is
+exhausted, the thin pool behavior is configurable with the --errorwhenfull
+y|n option to lvcreate or lvchange. The errorwhenfull setting applies
+only to writes; reading thin LVs can continue even when data space is
+exhausted.
+
+Command to change the handling of data space exhaustion of an existing
+thin pool LV:
+
+.B lvchange --errorwhenfull {y|n} VG/ThinPoolLV
+
+The current setting can be displayed with the lvs -o+error_when_full
+command.
+
+.B errorwhenfull n
+
+This is the default. Writes to thin LVs are accepted and queued, with the
+expectation that pool data space will be extended soon. Once data space
+is extended, the queued writes will be processed, and the thin pool will
+return to normal operation.
+
+While waiting to be extended, the thin pool will queue writes for up to 60
+seconds. If data space has not been extended after this time, the queued
+writes will return an error to the caller, e.g. the file system. This can
+result in file system corruption that may require fsck to repair.
+
+The 60 second timeout can be changed or disabled with the dm\-thin\-pool
+kernel module option
+.B no_space_timeout.
+This option sets the number of seconds that thin pools will queue writes.
+If set to 0, writes will not time out. Disabling timeouts may result in
+the system exhausting memory if too many writes are queued.
+
+.B errorwhenfull y
+
+Writes to thin LVs immediately return an error, and no writes are queued.
+In the case of a file system, this can result in corruption that may
+require fsck to repair (the specific consequences depend on the thin LV
+user.)
+
When data space is exhausted, the lvs command displays 100 under Data% for
the thin pool LV: