Login
[x]
Log in using an account from:
Fedora Account System
Red Hat Associate
Red Hat Customer
Or login using a Red Hat Bugzilla account
Forgot Password
Login:
Hide Forgot
Create an Account
Red Hat Bugzilla – Attachment 299362 Details for
Bug 220060
Improved documentation explaining cachefilesd culling limitations
[?]
New
Simple Search
Advanced Search
My Links
Browse
Requests
Reports
Current State
Search
Tabular reports
Graphical reports
Duplicates
Other Reports
User Changes
Plotly Reports
Bug Status
Bug Severity
Non-Defaults
|
Product Dashboard
Help
Page Help!
Bug Writing Guidelines
What's new
Browser Support Policy
5.0.4.rh83 Release notes
FAQ
Guides index
User guide
Web Services
Contact
Legal
This site requires JavaScript to be enabled to function correctly, please enable it.
[patch]
Documentation adjustment to describe cull limitations
cachefilesd-0.8-cull-doc.patch (text/plain), 3.97 KB, created by
David Howells
on 2008-03-27 17:14:43 UTC
(
hide
)
Description:
Documentation adjustment to describe cull limitations
Filename:
MIME Type:
Creator:
David Howells
Created:
2008-03-27 17:14:43 UTC
Size:
3.97 KB
patch
obsolete
>diff -ur cachefilesd-0.8-orig/cachefilesd.conf.5 cachefilesd-0.8/cachefilesd.conf.5 >--- cachefilesd-0.8-orig/cachefilesd.conf.5 2006-11-14 18:04:09.000000000 +0000 >+++ cachefilesd-0.8/cachefilesd.conf.5 2008-03-27 17:03:13.000000000 +0000 >@@ -106,9 +106,20 @@ > .SH CACHE CULLING > .P > The cache may need culling occasionally to make space. This involves >-discarding objects from the cache that have been used less recently than >-anything else. Culling is based on the access time of data objects. Empty >-directories are culled if not in use. >+discarding objects from the cache that are no longer marked as being in use by >+the network filesystem. Objects are selected from this group based on which >+has the least recent access time. Empty directories are culled if not in use. >+.P >+Note that this culling policy may result in objects remaining in cache longer >+than one might expect, because all references to the file by the network >+filesystem must be released before the file is culled. In the case of NFS, >+this means that the in-memory record of the inode must be discarded. This >+record will be pinned in memory whilst the inode has open file descriptors on >+it or bits of the inode are memory mapped. >+.P >+Once all references to it are released, the record will be retained in memory >+until memory pressure causes it to be discarded, or the inode is deleted or the >+filesystem is unmounted. > .P > Cache culling is done on the basis of the percentage of blocks and the > percentage of files available in the underlying filesystem. There are six >diff -ur cachefilesd-0.8-orig/howto.txt cachefilesd-0.8/howto.txt >--- cachefilesd-0.8-orig/howto.txt 2006-11-13 14:52:59.000000000 +0000 >+++ cachefilesd-0.8/howto.txt 2008-03-27 17:08:59.000000000 +0000 >@@ -205,6 +205,14 @@ > cache until appropriate parameter falls back beneath the run limit. > > >+Note that culling is limited by the retention of in-memory inode records by the >+Linux VFS layer. Even if an inode is not currently being used, the VFS may >+retain a record of it to avoid having to reget the inode later. If such an >+inode is pinning an object in the cache, then that object may not be culled >+until the VFS asks the network filesystem to discard the inode for whatever >+reason (deletion, server synchronisation, unmounting or memory pressure). >+ >+ > ========== > MONITORING > ========== >diff -ur cachefilesd-0.8-orig/README cachefilesd-0.8/README >--- cachefilesd-0.8-orig/README 2006-11-14 17:47:37.000000000 +0000 >+++ cachefilesd-0.8/README 2008-03-27 17:11:22.000000000 +0000 >@@ -16,6 +16,8 @@ > > (*) Cache culling. > >+ (*) Cull limitations. >+ > (*) Cache structure. > > (*) Security model and SELinux. >@@ -46,10 +48,10 @@ > > CacheFiles attempts to maintain at least a certain percentage of free space on > the filesystem, shrinking the cache by culling the objects it contains to make >-space if necessary - see the "Cache Culling" section. This means it can be >-placed on the same medium as a live set of data, and will expand to make use of >-spare space and automatically contract when the set of data requires more >-space. >+space if necessary - see the "Cache Culling" and "Cull limitations" sections. >+This means it can be placed on the same medium as a live set of data, and will >+expand to make use of spare space and automatically contract when the set of >+data requires more space. > > > ============ >@@ -223,6 +225,18 @@ > their atimes have changed or if the kernel module says it is still using them. > > >+================ >+CULL LIMITATIONS >+================ >+ >+Note that culling is limited by the retention of in-memory inode records by the >+Linux VFS layer. Even if an inode is not currently being used, the VFS may >+retain a record of it to avoid having to reget the inode later. If such an >+inode is pinning an object in the cache, then that object may not be culled >+until the VFS asks the network filesystem to discard the inode for whatever >+reason (deletion, server synchronisation, unmounting or memory pressure). >+ >+ > =============== > CACHE STRUCTURE > ===============
You cannot view the attachment while viewing its details because your browser does not support IFRAMEs.
View the attachment on a separate page
.
View Attachment As Diff
View Attachment As Raw
Actions:
View
|
Diff
Attachments on
bug 220060
: 299362