Re: [PATCHES] DOC: Wal update
Bruce Momjian wrote: Zdenek Kotala wrote: I add few sentences how to write cache works on Solaris platform. I have updated our documentation with the attached patch. I was able to verify all the information in this change. Thanks. I changed your original wording because the statement that UFS turns off write cache seemed unclear because the file system seems independent of the disk write cache. (What happens if you have UFS and ZFS on the same drive?) You are right UFS does not modify (write) cache setting and it is usually disabled by default on most disks. If ZFS and UFS are on same disk, than ZFS don't enable disk cache. It is a reason why put ZFS on separate disk is better. See http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide#Storage_Pools Anyway I think the attached wording is fine. Yes, it is. Zdenek PS: There are some articles about ZFS. http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide http://www.solarisinternals.com/wiki/index.php/ZFS_for_Databases ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [PATCHES] DOC: Wal update
Zdenek Kotala wrote: Bruce Momjian wrote: Zdenek Kotala wrote: I add few sentences how to write cache works on Solaris platform. I have updated our documentation with the attached patch. I was able to verify all the information in this change. Thanks. I changed your original wording because the statement that UFS turns off write cache seemed unclear because the file system seems independent of the disk write cache. (What happens if you have UFS and ZFS on the same drive?) You are right UFS does not modify (write) cache setting and it is usually disabled by default on most disks. If ZFS and UFS are on same disk, than ZFS don't enable disk cache. It is a reason why put ZFS on separate disk is better. See http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide#Storage_Pools Anyway I think the attached wording is fine. Yes, it is. Zdenek PS: There are some articles about ZFS. http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide http://www.solarisinternals.com/wiki/index.php/ZFS_for_Databases ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq -- Bruce Momjian [EMAIL PROTECTED]http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---(end of broadcast)--- TIP 5: don't forget to increase your free space map settings
Re: [PATCHES] DOC: Wal update
Zdenek Kotala wrote:
I add few sentences how to write cache works on Solaris platform.
I have updated our documentation with the attached patch. I was able to
verify all the information in this change.
I changed your original wording because the statement that UFS turns off
write cache seemed unclear because the file system seems independent of
the disk write cache. (What happens if you have UFS and ZFS on the same
drive?)
Anyway I think the attached wording is fine.
--
Bruce Momjian [EMAIL PROTECTED]http://momjian.us
EnterpriseDB http://postgres.enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
Index: doc/src/sgml/wal.sgml
===
RCS file: /cvsroot/pgsql/doc/src/sgml/wal.sgml,v
retrieving revision 1.51
diff -c -c -r1.51 wal.sgml
*** doc/src/sgml/wal.sgml 16 Dec 2007 14:05:12 - 1.51
--- doc/src/sgml/wal.sgml 29 Dec 2007 17:53:58 -
***
*** 65,74
write caching. On productnameFreeBSD/ use
applicationatacontrol/. (For SCSI disks use ulink
url=http://sg.torque.net/sg/sdparm.html;applicationsdparm//ulink
!to turn off literalWCE/.) On productnameWindows/ if
!varnamewal_sync_method/ is literalopen_datasync/ (the default),
!write caching is disabled by unchecking literalMy
!Computer\Open\{select disk
drive}\Properties\Hardware\Properties\Policies\Enable write caching on
the disk/. Also on Windows, literalfsync/ and
literalfsync_writethrough/ never do write caching.
--- 65,78
write caching. On productnameFreeBSD/ use
applicationatacontrol/. (For SCSI disks use ulink
url=http://sg.torque.net/sg/sdparm.html;applicationsdparm//ulink
!to turn off literalWCE/.) On productnameSolaris/ the disk
!write cache is controlled by ulink
!url=http://www.sun.com/bigadmin/content/submitted/format_utility.jsp;literalformat
!-e//ulink. (The Solaris acronymZFS/ file system is safe with
!disk write-cache enabled because it issues its own disk cache flush
!commands.) On productnameWindows/ if varnamewal_sync_method/
!is literalopen_datasync/ (the default), write caching is disabled
!by unchecking literalMy Computer\Open\{select disk
drive}\Properties\Hardware\Properties\Policies\Enable write caching on
the disk/. Also on Windows, literalfsync/ and
literalfsync_writethrough/ never do write caching.
---(end of broadcast)---
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