IO accounting - Revision history

Kir: /* See also */ added I/O limits

2015-07-08T19:46:21Z

‎See also: added I/O limits

Kir: minor rewording

2013-06-25T23:45:41Z

minor rewording

Kir: link to (and difference from) IO statistics

2013-06-25T23:23:12Z

link to (and difference from) IO statistics

Kir: Reverted edits by 116.71.15.55 (Talk) to last revision by Kir

2011-08-16T06:56:20Z

Reverted edits by 116.71.15.55 (Talk) to last revision by Kir

116.71.15.55: /* New resources */

2011-08-16T06:41:56Z

‎New resources

Kir: added link to ioprio

2009-02-12T08:30:25Z

added link to ioprio

Fayette: /* Debugging information */

2008-05-25T11:43:59Z

‎Debugging information

Fayette: /* General information */

2008-05-25T11:42:50Z

‎General information

Fayette: /* New resources */

2008-05-25T11:40:48Z

‎New resources

Fayette at 11:34, 25 May 2008

2008-05-25T11:34:14Z

@@ Line 109: / Line 109: @@
 == See also ==
 * [[IO statistics]]
 [[Category:Resource management]]

@@ Line 4: / Line 4: @@
 If you are interested in [[I/O priorities for containers]], it is described in a separate article.
-If you are looking for IO-scheduler level statistics, see [[IO statistics]] instead.
+If you are looking for IO scheduler (i.e. lower level) statistics, see [[IO statistics]] instead.
 == New resources ==

@@ Line 1: / Line 1: @@
-This page describes how accounting is done for I/O activity of VE processes. This feature is available beginning with OpenVZ kernels version <code>028test008</code>.
+This page describes accounting for I/O activity of CT processes, on a VFS I/O level.
 If you are interested in [[I/O priorities for containers]], it is described in a separate article.
 == New resources ==
@@ Line 23: / Line 26: @@
 == Proc interface ==
 === General information ===
 As was described in [[BC proc entries|another article]] each beancounter has its own <code>/proc/bc/$BCID</code> directory where subsystems add their entries. I/O accounting adds an <code>ioacct</code> entry to show I/O information. This entry contains the following information:
@@ Line 106: / Line 110: @@
 == See also ==
 * [[I/O priorities for containers]]
 [[Category:Resource management]]

@@ Line 7: / Line 7: @@
 ; read bytes
 : is the number of bytes read by tasks. Reads are always synchronous in the kernel so this type of resource is the easiest one.
 ; dirty bytes

@@ Line 7: / Line 7: @@
 ; read bytes
 : is the number of bytes read by tasks. Reads are always synchronous in the kernel so this type of resource is the easiest one.
 ; dirty bytes

@@ Line 36: / Line 36: @@
 === Debugging information ===
-When <code>CONFIG_UBC_DEBUG_IO</code>, is on <code>/proc/bc/ioacct_debug</code> is added. This entry contains a snapshot of current dirty pages with its beancounter in system. For example:
+When <code>CONFIG_UBC_DEBUG_IO</code>, is on <code>/proc/bc/ioacct_debug</code> is added. This entry contains a snapshot of current dirty pages with its beancounter. For example:
 <pre>
 # cat /proc/bc/ioacct_debug

@@ Line 22: / Line 22: @@
 == Proc interface ==
 === General information ===
-As it was described in [[BC proc entries|another article]] each beancounter has it's own <code>/proc/bc/$BCID</code> directory where subsystems add their entries. I/O accounting adds <code>ioacct</code> entry to show I/O information. This entry contains the following information:
+As was described in [[BC proc entries|another article]] each beancounter has its own <code>/proc/bc/$BCID</code> directory where subsystems add their entries. I/O accounting adds an <code>ioacct</code> entry to show I/O information. This entry contains the following information:
 <pre>
 # cat /proc/bc/101/ioacct
@@ Line 33: / Line 33: @@
 </pre>
-Note that <code>dirty</code> is not the size of a dirty data at the moment, but the size of a dirty data seen so far.
+Note that <code>dirty</code> is not the size of dirty data at the moment, but the size of dirty data seen so far.
 === Debugging information ===

@@ Line 4: / Line 4: @@
 The following resources are accounted:
 ; read bytes
-: is the amount of bytes read by tasks. Reads are always synchronous in kernel so this type of resources is the easiest one.
+: is the number of bytes read by tasks. Reads are always synchronous in the kernel so this type of resource is the easiest one.
 ; dirty bytes
-: is the amount of bytes that were dirty since VE start, i.&nbsp;e. data that isn't yet flushed to disk. This type of resources is accounted using [[RSS_fractions_accounting|page beancounters]] and the context the page was dirtied by is determined like this:
+: is the number of bytes that were dirty since VE start, i.&nbsp;e. data that isn't yet flushed to disk. This type of resource is accumulated using [[RSS_fractions_accounting|page beancounters]] and the context the page was dirtied by is determined like this:
 :* if a page is mapped it's "mapper" is used as this may happen in any context (unmapping of a page under memory pressure);
 :* if a page is not mapped — current BC is used as this can happen during usual write (writev) only.
 ; written bytes
-: is the amount of bytes flushed to disk. The beancounter to charge this to is the one the page was dirtied by.
+: is the number of bytes flushed to disk. The beancounter charged with this is the one by which the page was dirtied.
 ; canceled bytes
-: is the amount of bytes that were dirty but weren't flushed to disk.
+: is the number of bytes that were dirty but weren't flushed to disk.
 ; missed bytes
-: is the amount of bytes that were dirtied but the context (beancounter) wasn't saved due to lack of memory.
+: is the number of bytes that were dirtied but the context (beancounter) wasn't saved due to lack of memory.
 == Proc interface ==

← Older revision		Revision as of 11:34, 25 May 2008
Line 1:		Line 1:
−	This page describes how I/O activity of VE processes ~~is accounted~~. This feature is available ~~since~~ OpenVZ kernels version <code>028test008</code>.	+	This page describes how accounting is done for I/O activity of VE processes. This feature is available beginning with OpenVZ kernels version <code>028test008</code>.

	== New resources ==		== New resources ==