mkfs.xfs man page needs the default settings updated.
Manpages update for the new defaults, please review, I believe I got'em all.
Quoted 1 line
From
71011d480d52aaefe99ef252dfff513bf77f209eMon Sep 17 00:00:00 2001
From: Niv Sardi <[email protected]>
Date: Fri, 22 Feb 2008 16:48:32 +1100
Subject: [PATCH] Update mkfs manpage for new defaults:
log, attr and inodes v2,
Drop the ability to turn unwritten extents off completly, reduce imaxpct for big filesystems, less AGs for single disks configs.
--- xfsprogs/man/man8/mkfs.xfs.8 | 44 +++++------------------------------------ 1 files changed, 6 insertions(+), 38 deletions(-)
xfsprogs/man/man8/mkfs.xfs.8 +6 -38
@@ -304,7 +304,8 @@ bits. This specifies the maximum percentage of space in the filesystem that can be allocated to inodes. The default .I value -is 25%. Setting the +is 25% for filesystems under 1TB, 5% for filesystems under 50TB and 1% +for filesystems over 50TB. Setting the .I value to 0 means that essentially all of the filesystem can become inode blocks.
@@ -327,16 +328,10 @@ that does not have the inode alignment feature .BI attr[= value ] This is used to specify the version of extended attribute inline allocation policy to be used. -By default, this is zero. Once extended attributes are used for the +By default, this is 2. Once extended attributes are used for the first time, the version will be set to either one or two. The current version (two) uses a more efficient algorithm for managing -the available inline inode space than version one does, however, for -backward compatibility reasons (and in the absence of the -.B attr=2 -mkfs option, or the -.B attr2 -mount option), version one will be selected -by default when attributes are first used on a filesystem. +the available inline inode space than version one does. .RE .TP .BI \-l " log_section_options"
@@ -389,15 +384,9 @@ and directory block size, the minimum log size is larger than 512 blocks. .BI version= value This specifies the version of the log. The .I value -is either 1 or 2. Specifying +is either 1 or 2 (the default is 2). .B version=2 -enables the -.B sunit -suboption, and allows the logbsize to be increased beyond 32K. -Version 2 logs are automatically selected if a log stripe unit -is specified. See -.BR sunit " and " su -suboptions, below. +allows the logbsize to be increased beyond 32K. .TP .BI sunit= value This specifies the alignment to be used for log writes. The
@@ -430,27 +419,6 @@ suffixes). This value must be a multiple of the filesystem block size. Version 2 logs are automatically selected if the log .B su suboption is specified. -.TP -.BI lazy-count= value -This changes the method of logging various persistent counters -in the superblock. Under metadata intensive workloads, these -counters are updated and logged frequently enough that the superblock -updates become a serialisation point in the filesystem. The -.I value -can be either 0 or 1. -.IP -With -.BR lazy-count=1 , -the superblock is not modified or logged on every change of the -persistent counters. Instead, enough information is kept in -other parts of the filesystem to be able to maintain the persistent -counter values without needed to keep them in the superblock. -This gives significant improvements in performance on some configurations. -The default -.I value -is 0 (off) so you must specify -.B lazy-count=1 -if you want to make use of this feature. .RE .TP .BI \-n " naming_options"
Signature · 1 line
1.5.4.1
Signature · 2 lines
-- Niv Sardi
Quoted 1 line · Niv Sardi
Manpages update for the new defaults, please review, I believe I got'em all.
(hmm attachments make it slightly trickier to reply inline...)
Quoted 17 lines
Quoted 1 line
From
71011d480d52aaefe99ef252dfff513bf77f209eMon Sep 17 00:00:00 2001From: Niv Sardi <[email protected]>
Date: Fri, 22 Feb 2008 16:48:32 +1100
Subject: [PATCH] Update mkfs manpage for new defaults:log, attr and inodes v2,
Drop the ability to turn unwritten extents off completly, reduce imaxpct for big filesystems, less AGs for single disks configs.--- xfsprogs/man/man8/mkfs.xfs.8 | 44 +++++------------------------------------ 1 files changed, 6 insertions(+), 38 deletions(-)xfsprogs/man/man8/mkfs.xfs.8 +0
-0
xfsprogs/man/man8/mkfs.xfs.8 bits. · line 311
Quoted 9 lines
xfsprogs/man/man8/mkfs.xfs.8 +2
-1@@ -304,7 +304,8 @@ bits. This specifies the maximum percentage of space in the filesystem that can be allocated to inodes. The default .I value -is 25%. Setting the +is 25% for filesystems under 1TB, 5% for filesystems under 50TB and 1% +for filesystems over 50TB. Setting the .I value to 0 means that essentially all of the filesystem can become inode blocks.
Is it worth saying why you might want to override this? (i.e. why was it reduced for large filesystems, what was detrimental about having 25% at 50T?)
xfsprogs/man/man8/mkfs.xfs.8 that does not have the inode alignment feature · line 332
Quoted 7 lines
xfsprogs/man/man8/mkfs.xfs.8 +1
-1@@ -327,16 +328,10 @@ that does not have the inode alignment feature .BI attr[= value ] This is used to specify the version of extended attribute inline allocation policy to be used. -By default, this is zero. Once extended attributes are used for the +By default, this is 2. Once extended attributes are used for the first time, the version will be set to either one or two.
well, it will be set to what is specified, or the default, right? Again, why would I choose one over the other?
xfsprogs/man/man8/mkfs.xfs.8 that does not have the inode alignment feature · line 334
Quoted 9 lines
xfsprogs/man/man8/mkfs.xfs.8 +1
-7The current version (two) uses a more efficient algorithm for managing -the available inline inode space than version one does, however, for -backward compatibility reasons (and in the absence of the -.B attr=2 -mkfs option, or the -.B attr2 -mount option), version one will be selected -by default when attributes are first used on a filesystem. +the available inline inode space than version one does.
ah so I would never want to use 1? Or might I want to use it for backwards compatibility? or?
Quoted 8 lines
xfsprogs/man/man8/mkfs.xfs.8 +0
-1.RE .TP .BI \-l " log_section_options"@@ -389,15 +384,9 @@ and directory block size, the minimum log size is larger than 512 blocks. .BI version= value This specifies the version of the log. The .I value -is either 1 or 2. Specifying
xfsprogs/man/man8/mkfs.xfs.8 and directory block size, the minimum log size is larger than 512 blocks. · line 389
Quoted 10 lines
xfsprogs/man/man8/mkfs.xfs.8 +2
-7+is either 1 or 2 (the default is 2). .B version=2 -enables the -.B sunit -suboption, and allows the logbsize to be increased beyond 32K. -Version 2 logs are automatically selected if a log stripe unit -is specified. See -.BR sunit " and " su -suboptions, below. +allows the logbsize to be increased beyond 32K.
and it allows the sunit/su suboptions? And what's this 32K thing, and what's logbsize? The first-time reader may wonder what's special about 32K. Why would one want to use logv1 at this point, any reason? Perhaps it would be better to document limitations of v1 rather than the non-limitations of v2? Or just drop v1 altogether?
Quoted 18 lines
xfsprogs/man/man8/mkfs.xfs.8 +0
-11.TP .BI sunit= value This specifies the alignment to be used for log writes. The@@ -430,27 +419,6 @@ suffixes). This value must be a multiple of the filesystem block size. Version 2 logs are automatically selected if the log .B su suboption is specified. -.TP -.BI lazy-count= value -This changes the method of logging various persistent counters -in the superblock. Under metadata intensive workloads, these -counters are updated and logged frequently enough that the superblock -updates become a serialisation point in the filesystem. The -.I value -can be either 0 or 1. -.IP -With -.BR lazy-count=1 ,
xfsprogs/man/man8/mkfs.xfs.8 suffixes). This value must be a multiple of the filesystem block size. · line 453
Quoted 10 lines
xfsprogs/man/man8/mkfs.xfs.8 +0
-10-the superblock is not modified or logged on every change of the -persistent counters. Instead, enough information is kept in -other parts of the filesystem to be able to maintain the persistent -counter values without needed to keep them in the superblock. -This gives significant improvements in performance on some configurations. -The default -.I value -is 0 (off) so you must specify -.B lazy-count=1 -if you want to make use of this feature.
lazy-count is no longer a configurable option?
-Eric
Quoted 9 lines
xfsprogs/man/man8/mkfs.xfs.8 +0
-2.RE .TP .BI \-n " naming_options" -- 1.5.4.1 -- Niv Sardi
Quoted 3 lines · Eric Sandeen
Quoted 1 line · Niv Sardi
Manpages update for the new defaults, please review, I believe I got'em all.
(btw review was a bit pedantic becase there are always a million questions about tuning & options. Let's try to be as clear as we can in the manpage at least...)
-Eric
Re: [REVIEW] mkfs.xfs man page needs the default settings updated, TAKE 2.
Thanks to Eric for the comments, is this better ?
Cheers,
Signature · 1 line
Niv Sardi
Quoted 1 line
From
7e0e328663858ecf13f35678f1a6d349c3d4dd5aMon Sep 17 00:00:00 2001
From: Niv Sardi <[email protected]>
Date: Fri, 22 Feb 2008 16:48:32 +1100
Subject: [PATCH] Update mkfs manpage for new defaults:
log, attr and inodes v2,
Drop the ability to turn unwritten extents off completly, reduce imaxpct for big filesystems, less AGs for single disks configs.
--- xfsprogs/man/man8/mkfs.xfs.8 | 41 ++++++++++++++++++----------------------- 1 files changed, 18 insertions(+), 23 deletions(-)
xfsprogs/man/man8/mkfs.xfs.8 +18 -23
@@ -304,10 +304,16 @@ bits. This specifies the maximum percentage of space in the filesystem that can be allocated to inodes. The default .I value -is 25%. Setting the +is 25% for filesystems under 1TB, 5% for filesystems under 50TB and 1% +for filesystems over 50TB. Setting the .I value -to 0 means that essentially all of the filesystem can -become inode blocks. +to 0 means that essentially all of the filesystem can become inode +blocks. Note that this is only used by inode32 (on 32bits platforms), +and is ignored on 64bits platforms. On 32 bits platforms, we can only +use the first TB of disk space for inodes, so the allocator will try +to avoid this region, hence miss-using the first AG if this is set to +high (the worst case is a 4TB filesystem where a full AG will be +untouched by anything but inodes with a 25% maxpct). .TP .BI align[= value ] This is used to specify that inode allocation is or is not aligned. The
@@ -325,18 +331,11 @@ that does not have the inode alignment feature (any release of IRIX before 6.2, and IRIX 6.2 without XFS patches). .TP .BI attr[= value ] -This is used to specify the version of extended attribute inline allocation -policy to be used. -By default, this is zero. Once extended attributes are used for the -first time, the version will be set to either one or two. -The current version (two) uses a more efficient algorithm for managing -the available inline inode space than version one does, however, for -backward compatibility reasons (and in the absence of the -.B attr=2 -mkfs option, or the -.B attr2 -mount option), version one will be selected -by default when attributes are first used on a filesystem. +This is used to specify the version of extended attribute inline +allocation policy to be used. By default, this is 2. The current +version (two) uses a more efficient algorithm for managing the +available inline inode space than version one does. This option is +kept for backward compatibility, attr2 was added in kernel 2.6.16. .RE .TP .BI \-l " log_section_options"
@@ -389,15 +388,11 @@ and directory block size, the minimum log size is larger than 512 blocks. .BI version= value This specifies the version of the log. The .I value -is either 1 or 2. Specifying +is either 1 or 2 (the default is 2). .B version=2 -enables the -.B sunit -suboption, and allows the logbsize to be increased beyond 32K. -Version 2 logs are automatically selected if a log stripe unit -is specified. See -.BR sunit " and " su -suboptions, below. +allows bigger log buffer size (version 1 had a limit at 32K), and the +use of the sunit and su options. Possibility to use version=1 is left +for backward compatibility only. .TP .BI sunit= value This specifies the alignment to be used for log writes. The
Signature · 1 line
1.5.4.3
Re: [REVIEW] mkfs.xfs man page needs the default settings updated, TAKE 2.
Quoted 27 lines · Niv Sardi
Thanks to Eric for the comments, is this better ?
Cheers,
-- Niv Sardi
From
7e0e328663858ecf13f35678f1a6d349c3d4dd5aMon Sep 17 00:00:00 2001
From: Niv Sardi <[email protected]>
Date: Fri, 22 Feb 2008 16:48:32 +1100
Subject: [PATCH] Update mkfs manpage for new defaults:log, attr and inodes v2,
Drop the ability to turn unwritten extents off completly, reduce imaxpct for big filesystems, less AGs for single disks configs.--- xfsprogs/man/man8/mkfs.xfs.8 | 41 ++++++++++++++++++----------------------- 1 files changed, 18 insertions(+), 23 deletions(-)xfsprogs/man/man8/mkfs.xfs.8 +0
-0@@ -304,10 +304,16 @@ bits. This specifies the maximum percentage of space in the filesystem that can be allocated to inodes. The default
xfsprogs/man/man8/mkfs.xfs.8 bits. · line 312
Quoted 10 lines
xfsprogs/man/man8/mkfs.xfs.8 +5
-3.I value -is 25%. Setting the +is 25% for filesystems under 1TB, 5% for filesystems under 50TB and 1% +for filesystems over 50TB. Setting the .I value -to 0 means that essentially all of the filesystem can -become inode blocks. +to 0 means that essentially all of the filesystem can become inode +blocks. Note that this is only used by inode32 (on 32bits platforms), +and is ignored on 64bits platforms.
Really? The m_maxicount tests in xfs_ialloc_ag_alloc and xfs_dialloc don't seem to care about inode32 or not, unless I'm missing something.
xfsprogs/man/man8/mkfs.xfs.8 bits. · line 314
Quoted 2 lines
xfsprogs/man/man8/mkfs.xfs.8 +2
-0+On 32 bits platforms, we can only +use the first TB of disk space for inodes,
well, that depends on the inode size...
xfsprogs/man/man8/mkfs.xfs.8 bits. · line 315
Quoted 1 line
xfsprogs/man/man8/mkfs.xfs.8 +1
-0+so the allocator will try
the data allocator...
xfsprogs/man/man8/mkfs.xfs.8 bits. · line 316
Quoted 3 lines
xfsprogs/man/man8/mkfs.xfs.8 +3
-0+to avoid this region, hence miss-using the first AG if this is set to +high (the worst case is a 4TB filesystem where a full AG will be +untouched by anything but inodes with a 25% maxpct).
ah, ok. It becomes slightly clearer. :)
How about...
maxpct=value
This specifies the maximum percentage of space in the filesystem that can be allocated to inodes. The default value is 25% for filesystems under 1TB, 5% for filesystems under 50TB and 1% for filesystems over 50TB.
In the default inode allocation mode, inode blocks are chosen such that inode numbers will not exceed 32 bits, which restricts the inode blocks to the lower portion of the filesystem. The data block allocator will avoid these low blocks to accommodate the specified maxpct, so a high value may result in a filesystem with nothing but inodes in a significant portion of the lower blocks of the filesystem. (This restriction is not present when the filesystem is mounted with the "inode64" option on 64-bit platforms).
Setting the value to 0 means that essentially all of the filesystem can become inode blocks, subject to inode32 restrictions.
This value can be modified with xfs_growfs(8).
eh... could be better... but how's it sound?
Quoted 14 lines
xfsprogs/man/man8/mkfs.xfs.8 +0
-7.TP .BI align[= value ] This is used to specify that inode allocation is or is not aligned. The@@ -325,18 +331,11 @@ that does not have the inode alignment feature (any release of IRIX before 6.2, and IRIX 6.2 without XFS patches). .TP .BI attr[= value ] -This is used to specify the version of extended attribute inline allocation -policy to be used. -By default, this is zero. Once extended attributes are used for the -first time, the version will be set to either one or two. -The current version (two) uses a more efficient algorithm for managing -the available inline inode space than version one does, however, for -backward compatibility reasons (and in the absence of the
xfsprogs/man/man8/mkfs.xfs.8 that does not have the inode alignment feature · line 338
Quoted 10 lines
xfsprogs/man/man8/mkfs.xfs.8 +5
-5-.B attr=2 -mkfs option, or the -.B attr2 -mount option), version one will be selected -by default when attributes are first used on a filesystem. +This is used to specify the version of extended attribute inline +allocation policy to be used. By default, this is 2. The current +version (two) uses a more efficient algorithm for managing the +available inline inode space than version one does. This option is +kept for backward compatibility, attr2 was added in kernel 2.6.16.
attr[=value] (hmm why the brackets; is value really optional?)
This is used to specify the version of extended attribute inline allocation policy to be used. By default, this is 2, which uses an efficient algorithm for managing the available inline inode space between attribute and extent data.
The previous version 1, which has fixed regions for attribute and extent data, is kept for backwards compatibility with kernels older than version 2.6.16.
(aside: will older kernels refuse to mount attr2 filesystems? I suppose they will but I'm not sure they need to?)
-Eric
Quoted 10 lines
xfsprogs/man/man8/mkfs.xfs.8 +1
-1.RE .TP .BI \-l " log_section_options"@@ -389,15 +388,11 @@ and directory block size, the minimum log size is larger than 512 blocks. .BI version= value This specifies the version of the log. The .I value -is either 1 or 2. Specifying +is either 1 or 2 (the default is 2). .B version=2
xfsprogs/man/man8/mkfs.xfs.8 and directory block size, the minimum log size is larger than 512 blocks. · line 395
Quoted 10 lines
xfsprogs/man/man8/mkfs.xfs.8 +3
-7-enables the -.B sunit -suboption, and allows the logbsize to be increased beyond 32K. -Version 2 logs are automatically selected if a log stripe unit -is specified. See -.BR sunit " and " su -suboptions, below. +allows bigger log buffer size (version 1 had a limit at 32K), and the +use of the sunit and su options. Possibility to use version=1 is left +for backward compatibility only.
version=value
This specifies the version of the log. The current default is 2, which allows for larger log buffer sizes, as well as supporting stripe-aligned log writes (see the sunit and su options, below).
The previous version 1, which is limited to 32k log buffers and does not support stripe-aligned writes, is kept for backwards compatibility with kernels older than version 2.XX.XX
Quoted 4 lines
xfsprogs/man/man8/mkfs.xfs.8 +0
-1.TP .BI sunit= value This specifies the alignment to be used for log writes. The -- 1.5.4.3
Re: [REVIEW] mkfs.xfs man page needs the default settings updated, TAKE 2.
In reply to Niv SardiQuoted 1 line · Niv Sardi
Thanks to Eric for the comments, is this better ?
Not much of a changelog....
Quoted 7 lines
xfsprogs/man/man8/mkfs.xfs.8 +0
-0@@ -304,10 +304,16 @@ bits. This specifies the maximum percentage of space in the filesystem that can be allocated to inodes. The default
xfsprogs/man/man8/mkfs.xfs.8 bits. · line 312
Quoted 10 lines
xfsprogs/man/man8/mkfs.xfs.8 +5
-3.I value -is 25%. Setting the +is 25% for filesystems under 1TB, 5% for filesystems under 50TB and 1% +for filesystems over 50TB. Setting the .I value -to 0 means that essentially all of the filesystem can -become inode blocks. +to 0 means that essentially all of the filesystem can become inode +blocks. Note that this is only used by inode32 (on 32bits platforms), +and is ignored on 64bits platforms. On 32 bits platforms, we can only
This is wrong. inode32 is the default on 64 bit platforms as well, and it matters then as well.
xfsprogs/man/man8/mkfs.xfs.8 bits. · line 313
Quoted 1 line
xfsprogs/man/man8/mkfs.xfs.8 +1
-0+use the first TB of disk space for inodes, so the allocator will try
That's not strictly true, either - it depends on inode size; 2k inodes stratch this to 8TB.
xfsprogs/man/man8/mkfs.xfs.8 bits. · line 316
Quoted 3 lines
xfsprogs/man/man8/mkfs.xfs.8 +3
-0+to avoid this region, hence miss-using the first AG if this is set to +high (the worst case is a 4TB filesystem where a full AG will be +untouched by anything but inodes with a 25% maxpct).
No, it doesn't "miss-use" this space - it reserves it for inodes and metadata and prevents data allocation in those AGs until all other space is consumed.
Cheers,
Dave.
Signature · 3 lines
Dave Chinner Principal Engineer SGI Australian Software Group
Re: [REVIEW] mkfs.xfs man page needs the default settings updated, TAKE 2.
In reply to Eric SandeenQuoted 33 lines · Eric Sandeen
Quoted 32 lines · Niv Sardi
Thanks to Eric for the comments, is this better ?
Cheers,
-- Niv Sardi
From
7e0e328663858ecf13f35678f1a6d349c3d4dd5aMon Sep 17 00:00:00 2001
From: Niv Sardi <[email protected]>
Date: Fri, 22 Feb 2008 16:48:32 +1100
Subject: [PATCH] Update mkfs manpage for new defaults:log, attr and inodes v2,
Drop the ability to turn unwritten extents off completly, reduce imaxpct for big filesystems, less AGs for single disks configs.--- xfsprogs/man/man8/mkfs.xfs.8 | 41 ++++++++++++++++++----------------------- 1 files changed, 18 insertions(+), 23 deletions(-)xfsprogs/man/man8/mkfs.xfs.8 +2
-1@@ -304,10 +304,16 @@ bits. This specifies the maximum percentage of space in the filesystem that can be allocated to inodes. The default .I value -is 25%. Setting the +is 25% for filesystems under 1TB, 5% for filesystems under 50TB and 1% +for filesystems over 50TB. Setting the .I value
Quoted 8 lines
xfsprogs/man/man8/mkfs.xfs.8 bits.
Quoted 5 lines
xfsprogs/man/man8/mkfs.xfs.8 +3
-2-to 0 means that essentially all of the filesystem can -become inode blocks. +to 0 means that essentially all of the filesystem can become inode +blocks. Note that this is only used by inode32 (on 32bits platforms), +and is ignored on 64bits platforms.Really? The
m_maxicounttests inxfs_ialloc_ag_allocandxfs_diallocdon't seem to care about inode32 or not, unless I'm missing something.
See xfs_set_maxicount() and then how it is used in xfs_initialize_perag() to set up pag->pagi_inodeok, pag->pagf_metadata and mp->m_maxagi which are used by the allocator....
Quoted 19 lines
How about...
maxpct=value
This specifies the maximum percentage of space in the filesystem that can be allocated to inodes. The default value is 25% for filesystems under 1TB, 5% for filesystems under 50TB and 1% for filesystems over 50TB.In the default inode allocation mode, inode blocks are chosen such that inode numbers will not exceed 32 bits, which restricts the inode blocks to the lower portion of the filesystem. The data block allocator will avoid these low blocks to accommodate the specified maxpct, so a high value may result in a filesystem with nothing but inodes in a significant portion of the lower blocks of the filesystem. (This restriction is not present when the filesystem is mounted with the "inode64" option on 64-bit platforms).
Quoted 7 lines
Setting the value to 0 means that essentially all of the filesystem can become inode blocks, subject to inode32 restrictions.
This value can be modified with
xfs_growfs(8).eh... could be better... but how's it sound?
Much better.
Cheers,
Dave.
Signature · 3 lines
Dave Chinner Principal Engineer SGI Australian Software Group