This case was approved at yesterdays PSARC meeting. Brian Utterback wrote: > Template Version: @(#)sac_nextcase 1.68 02/23/09 SMI > This information is Copyright 2009 Sun Microsystems > 1. Introduction > 1.1. Project/Component Working Name: > Increase the maximum default ufs log size (ldl_maxlogsize) from 64 > Mbytes to 512 Mbytes. > 1.2. Name of Document Author/Supplier: > Author: Owen Roberts > 1.3 Date of This Document: > 18 May, 2009 > 4. Technical Description > Proposal: > > Increase the maximum default ufs log size (ldl_maxlogsize) from 64 > Mbytes to 512 Mbytes. > > > Detail: > > The default maximum ufs log size has been 64 Mbytes since ufs > logging was integrated into Solaris 7. The algorithhm used to > determine the size of the log being approximately 1 Mbyte of log > allocated for every 1 Gbyte of file system up to a maximum > specified by the kernel variable ldl_maxlogsize which is set > to 64 Mbytes. > > It has not been possible to increase the default maximum size of > the ufs log in the past due to the restriction of lufsboot only > being able to handle a 64 Mbyte dirty log. A larger dirty log would > result in memory exhaustion in this early stage of the boot process. > > The requirement to increase the maximum default ufs log size > is to overcome a problem now seen due to larger file systems. > In certain circumstances it is possible to fill the log in a single > file system transaction resulting in a file system hang. > With the introduction of new boot to the sparc architecture in > Solaris 10 update 6 (new boot for the x86 architecture was > delivered in Solaris 10 update 1) the 64 Mbyte constraint is no > longer applicable allowing the opportunity to provide a solution > for the full log hang as documented in the bugs 4673568 and > 6709826. > > The work around to CRs 4673568 and 6709826 is to either disable > ufs logging (which potentially exposes customers to delayed > boots while waiting for an fsck to complete), or for customers > to manually increase the ldl_maxlogsize as per the Sun Alert > 200854. > > The decision to increase the ldl_maxlogsize to 512 Mbytes was > based on the fact that this size log would prevent a full log > hang in a 16 TByte file system which is the maximum ufs file > system size. > > > Release binding: > > Patch > > > Documenation Impact: > > Update to the ufs (7FS) man page. > > 147c147 > < The UFS log is allocated from free blocks on the file system, and is sized > at approximately 1 Mbyte per 1 Gbyte of file system, up to a maximum of 64 > Mbytes. The log is continually flushed as it fills up. The log is also > flushed when the file system is unmounted or as a result of a \fBlockfs\fR > command. > --- >> The UFS log is allocated from free blocks on the file system, and is sized >> at approximately 1 Mbyte per 1 Gbyte of file system, up to 256 Mbytes. The >> log size may be larger (up to a maximum of 512 Mbytes) based upon the number >> of cylinder groups present in the file system. The log is continually >> flushed as it fills up. The log is also flushed when the file system is >> unmounted or as a result of a \fBlockfs\fR command. > > Update to the mount_ufs (1M) man page. > > 134c134 > < The log is allocated from free blocks in the file system, and is sized > approximately 1 Mbyte per 1 Gbyte of file system, up to a maximum of 64 > Mbytes. > --- >> The log is allocated from free blocks in the file system, and is sized >> approximately 1 Mbyte per 1 Gbyte of file system, up to 256 Mbytes. The log >> size may be larger (up to a maximum of 512 Mbytes) based upon the number of >> cylinder groups present in the file system. > > Update to the System Administration Guide answerbook under the "The UFS > File System" section. > > > References: > > 1. PSARC 2004/454 Solaris Boot Architecture > > 2. PSARC 2006/525 new-boot sparc > > 3. CR 4673568 system hangs with ufs logging suspect > > 4. CR 6709826 ufs log size should be large enough by default to avoid panic > described in Sun Alert 200854 > > 5. Sun Alert 200854 Solaris System May Hang Due to Insufficient Log Space > Allocation on UFS With Logging Enabled > > 6. Resources and Schedule > 6.4. Steering Committee requested information > 6.4.1. Consolidation C-team Name: > ON > 6.5. ARC review type: FastTrack > 6.6. ARC Exposure: open >
-- blu "The advertising giveth and the EULA taketh away." ---------------------------------------------------------------------- Brian Utterback - Solaris RPE, Sun Microsystems, Inc. Ph:877-259-7345, Em:brian.utterback-at-ess-you-enn-dot-kom
