Bug 1290673

Document URL:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html-single/Performance_Tuning_Guide/index.html 

Section Number and Name: 
Multiple. See Additional Information.

Describe the issue: 
Miscellaneous typos, wording

Suggestions for improvement: 
Please see below.

Additional information: 
Bugzilla - Performance Guide Errata

4.3.2.1

Typo - errant space in "of"

OLD:
Specifies the percentage o f physical RAM considered when overcommit_memory is set to 2. The default value is 50.

NEW:
Specifies the percentage of physical RAM considered when overcommit_memory is set to 2. The default value is 50.


Possessive form of process 

OLD:
Processes spawned by an adjusted process inherit that process's oom_score.
NEW:
Processes spawned by an adjusted process inherit the oom_score of the process.
NEW:
Processes spawned by an adjusted process inherit that process' oom_score.


Incomplete sentence, verb agreement, unnecessary comma

OLD:
swappiness
A value from 0 to 100 which controls the degree to which the system favour anonymous memory or the page cache. A high value improves file-system performance, while aggressively swapping less active processes out of RAM. A low value avoids swapping processes out of memory, which usually decrease latency, at the cost of I/O performance. The default value is 60.

NEW:
The swappiness value, ranging from 0 to 100, controls the degree to which the system favours anonymous memory or the page cache. A high value improves file-system performance while aggressively swapping less active processes out of RAM. A low value avoids swapping processes out of memory, which usually decreases latency at the cost of I/O performance. The default value is 60.

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4.2.3
Missing version number in shmall, shmax, 

OLD:
Defines the total amount of shared memory in pages that can be used on the system at one time. As of Red Hat Enterprise Linux, the default value is 1<<24, or 33554432 pages.

NEW:
Defines the total amount of shared memory in pages that can be used on the system at one time. As of Red Hat Enterprise Linux 7, the default value is 1<<24, or 33554432 pages.


5.1.3.4
Maximum GFS2 capacity doesn't match other documentation:
https://access.redhat.com/solutions/1532

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5.2.1.
The si/so is not quite clear and seems to be opposite to the manpage. 

Specifically, the vmstat manpage shows:
si: Amount of memory swapped in from disk (/s).
so: Amount of memory swapped to disk (/s).

The documentation has:
Swap in, or writes to swap space, in KB.
Swap out, or reads from swap space, in KB.

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5.2.2.3
Suggest removing redundant "you"

OLD:
This can help you to identify when you are hitting the operations-per-second limit of a device.

NEW:
This can help to identify when you are hitting the operations-per-second limit of a device.



5.3.7.3
s/It's/Its/, run-on

OLD:
Tuning should always be done to optimize the system based on it's current workload. This section deals only with optimizing a BTRFS, for creation and mounting options see the Red Hat Enterprise Linux 7 Storage Administration Guide, 

NEW:
Tuning should always be done to optimize the system based on its current workload. This section deals only with optimizing a BTRFS file system. For creation and mounting options see the Red Hat Enterprise Linux 7 Storage Administration Guide, 


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5.3.7.3.1

Remove contraction, redundant parenthetical.

OLD:
compress=zlib - Better compression ratio. It's the default and safe for older kernels.(default).

NEW:
compress=zlib - Better compression ratio. It is the default and safe for older kernels.


OLD:
compress-force=method - Enable compression even for files that don't compress well, like videos and images of disks. 

NEW:
compress-force=method - Enable compression even for files that do not compress well, such as videos and images of disks.

Formatting example should be clearer

OLD:
$ btrfs filesystem defragment -calg

NEW:
$ btrfs filesystem defragment -c[ALG]

where ALG is either zlib or lzo.