Служебная программа Windows® PE (Wpeutil) — это программа командной строки, которая позволяет выполнять различные команды в сеансе Windows PE. Например, можно завершить работу компьютера или перезапустить Windows PE, включить или отключить брандмауэр, задать языковые параметры и настроить сеть.
Примечание.
Wpeutil позволяет указывать только по одной команде на строке.
Параметры командной строки Wpeutil
Программа Wpeutil использует следующие правила:
Команда
Свойства
Создает файл подкачки указанного размера по указанному пути. По умолчанию используется путь C:\pagefile.sys и размер 64 МБ. Необходимо указать хотя бы один параметр. Пример: wpeutil CreatePageFile /path=C:\pagefile.sys .
Важно!
Если файл подкачки существует, значение параметра /CreatePageFile должно быть больше или равно текущему размеру этого файла, иначе команда завершится с ошибкой.
Отключает поддержку расширенных символов для DOS-совместимых имен файлов (формат 8.3: имя — 8 знаков, расширение — 3 знака) для тома, содержащего . Значение должно указывать корневой каталог тома (например, C:\). При отключении данного параметра все файлы, созданные с использованием расширенных символов, преобразуются в файлы с короткими именами. Эта команда применяется только к томам NTFS.
Отключает брандмауэр. Для этой команды аргументы не требуются.
Разрешает использование расширенных символов в именах файлов формата 8.3 на томе, содержащем . Значение должно указывать корневой каталог тома (например, C:\). Эта команда применяется только к томам NTFS.
Примечание.
Если устанавливается операционная система с языком, в котором расширенные символы разрешены по умолчанию, например ja-JP или ko-KR, или копия Windows PE используется с языком без разрешенных расширенных символов, например en-US, при первой загрузке установка выдает ошибку Chkdsk. Включение данного параметра перед выполнением установки на данный том предотвращает запуск команды Chkdsk.
Включает брандмауэр. Для этой команды аргументы не требуются.
Настраивает сетевые компоненты и драйверы, а также задает случайное имя компьютера.
Выводит список поддерживаемых сочетаний клавиш (имя и код) для определенного значения кода языка (LCID). Раскладки клавиатуры также обновляются в разделе реестра: HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\WinPE\KeyboardLayouts. Список допустимых кодов языка см. на веб-странице, посвященной списку значений кодов языка (LCID). Пример:
wpeutil ListKeyboardLayouts 0x0409
wpeutil ListKeyboardLayouts 1033
Перезапускает текущий сеанс Windows PE.
Примечания
Текущий сеанс Windows PE можно перезапустить, выполнив следующие команды wpeutil.exe:
wpeutil shutdown
Останавливает ведение журнала и сохраняет особый профиль в расположении, которое пользователь указал ранее с помощью команды DISM /enable-profiling. Дополнительные сведения о параметре командной строки /enable-profiling см. в разделе Параметры командной строки обслуживания среды предустановки Windows. Пример:
Задает раскладку клавиатуры для текущего сеанса Windows PE. Это затронет процессы после успешного выполнения команды. Чтобы ознакомиться со списком поддерживаемых раскладок клавиатуры, выполните команду ListKeyboardLayouts . Чтобы задать раскладку клавиатуры en-US, используйте следующую команду:
wpeutil SetKeyboardLayout 0409:00000409
Устанавливает язык. Параметр использует формат кода языка (например, en-US для американского английского языка). Можно указать несколько языков в приоритетном порядке, разделяя их запятыми. Пример:
Устанавливает региональные настройки пользователя. Параметр использует формат кода языка (например, en-US для американского английского языка). Можно указать несколько языков в приоритетном порядке, разделяя их запятыми. Пример:
Завершает текущий сеанс Windows PE.
Примечания
Кроме того, в окне командной строки можно выполнить следующие действия:
Нажмите кнопку Закрыть.
Обновляет сведения о методе загрузки Windows PE. Сведения сохраняются в разделе реестра HKLM\SYSTEM\CurrentControlSet\Control. Результаты могут измениться после загрузки дополнительной поддержки драйверов.
Примечания
WpeUtil UpdateBootInfo заполняет реестр сведениями о загрузке Windows PE. Чтобы определить источник загрузки Windows PE, просмотрите следующие значения:
Имя сервера служб развертывания Windows PEBootServerName
Имя сервера служб развертывания Windows PEBootServerName
IP-адрес сервера служб развертывания Windows PEBootServerAddr
Буква диска источника addressPEBootRamdiskSourceDrive, если доступно
Если загрузка служб развертывания Windows не выполняется, то для определения источника загрузки Windows PE рекомендуется сначала проверить раздел реестра PEBootRamdiskSourceDrive. Если его нет, просканируйте диски правильного типа PEBootType и выполните поиск файла тегов, указывающего на загрузочный диск.
Во время процедуры запуска Windows PE эта команда выполнит блокирование в ожидании инициализации съемных устройств хранения, например жестких дисков USB.
См. также
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Introduction to page files
A page file (also known as a «paging file») is an optional, hidden system file on a hard disk.
Functionality
Page files have the following functionalities.
Physical extension of RAM
Page files enable the system to remove infrequently accessed modified pages from physical memory to let the system use physical memory more efficiently for more frequently accessed pages.
Application requirements
Some products or services require a page file for various reasons. For specific information, check the product documentation.
For example, the following Windows servers requires page files:
Windows Server domain controllers (DCs)
DFS Replication (DFS-R) servers
Certificate servers
ADAM/LDS servers
This is because the algorithm of the database cache for Extensible Storage Engine (ESENT, or ESE in Microsoft Exchange Server) depends on the «\Memory\Transition Pages RePurposed/sec» performance monitor counter. A page file is required to make sure that the database cache can release memory if other services or applications request memory.
For Windows Server 2012 Hyper-V and Windows Server 2012 R2 Hyper-V, the page file of the management OS (commonly called the host OS) should be left at the default of setting of «System Managed» .
Support for system crash dumps
Page files can be used to «back» (or support) system crash dumps and extend how much system-committed memory (also known as “virtual memory”) a system can support.
For more information about system crash dumps, see system crash dump options.
Page files in Windows with large physical memory
When large physical memory is installed, a page file might not be required to support the system commit charge during peak usage. For example, 64-bit versions of Windows and Windows Server support more physical memory (RAM) than 32-bit versions support. The available physical memory alone might be large enough.
However, the reason to configure the page file size has not changed. It has always been about supporting a system crash dump, if it is necessary, or extending the system commit limit, if it is necessary. For example, when a lot of physical memory is installed, a page file might not be required to back the system commit charge during peak usage. The available physical memory alone might be large enough to do this. However, a page file or a dedicated dump file might still be required to back a system crash dump.
System committed memory
Page files extend how much «committed memory» (also known as «virtual memory») is used to store modified data.
The system commit memory limit is the sum of physical memory and all page files combined. It represents the maximum system-committed memory (also known as the «system commit charge») that the system can support.
The system commit charge is the total committed or «promised» memory of all committed virtual memory in the system. If the system commit charge reaches the system commit limit, the system and processes might not get committed memory. This condition can cause freezing, crashing, and other malfunctions. Therefore, make sure that you set the system commit limit high enough to support the system commit charge during peak usage.
The system committed charge and system committed limit can be measured on the Performance tab in Task Manager or by using the «\Memory\Committed Bytes» and «\Memory\Commit Limit» performance counters. The \Memory% Committed Bytes In Use counter is a ratio of \Memory\Committed Bytes to \Memory\Commit Limit values.
System-managed page files automatically grow up to three times the physical memory or 4 GB (whichever is larger, but no more than one-eighth of the volume size) when the system commit charge reaches 90 percent of the system commit limit. This assumes that enough free disk space is available to accommodate the growth.
How to determine the appropriate page file size for 64-bit versions of Windows
Page file sizing depends on the system crash dump setting requirements and the peak usage or expected peak usage of the system commit charge. Both considerations are unique to each system, even for systems that are identical. This means that page file sizing is also unique to each system and cannot be generalized.
Determine the appropriate page file size
Use the following considerations for page file sizing for all versions of Windows and Windows Server.
Crash dump setting
If you want a crash dump file to be created during a system crash, a page file or a dedicated dump file must exist and be large enough to back up the system crash dump setting. Otherwise, a system memory dump file is not created.
For more information, see Support for system crash dumps section.
Peak system commit charge
The system commit charge cannot exceed the system commit limit. This limit is the sum of physical memory (RAM) and all page files combined. If no page files exist, the system commit limit is slightly less than the physical memory that is installed. Peak system-committed memory usage can vary greatly between systems. Therefore, physical memory and page file sizing also vary.
Quantity of infrequently accessed pages
The purpose of a page file is to back (support) infrequently accessed modified pages so that they can be removed from physical memory. This provides more available space for more frequently accessed pages. The «\Memory\Modified Page List Bytes» performance counter measures, in part, the number of infrequently accessed modified pages that are destined for the hard disk. However, be aware that not all the memory on the modified page list is written out to disk. Typically, several hundred megabytes of memory remains resident on the modified list. Therefore, consider extending or adding a page file if all the following conditions are true:
More available physical memory (\Memory\Available MBytes) is required.
The modified page list contains a significant amount of memory.
The existing page files are fairly full (\Paging Files(*)% Usage).
Support for system crash dumps
A system crash (also known as a “bug check” or a «Stop error») occurs when the system cannot run correctly. The dump file that is produced from this event is called a system crash dump. A page file or dedicated dump file is used to write a crash dump file (Memory.dmp) to disk. Therefore, a page file or a dedicated dump file must be large enough to support the kind of crash dump selected. Otherwise, the system cannot create the crash dump file.
During startup, system-managed page files are sized respective to the system crash dump settings. This assumes that enough free disk space exists.
System crash dump setting
Minimum page file size requirement
Small memory dump (256 KB)
1 MB
Kernel memory dump
Depends on kernel virtual memory usage
Complete memory dump
1 x RAM plus 257 MB*
Automatic memory dump
Depends on kernel virtual memory usage. For details, see Automatic memory dump.
* 1 MB of header data and device drivers can total 256 MB of secondary crash dump data.
The Automatic memory dump setting is enabled by default. This is a setting instead of a kind of crash dump. This setting automatically selects the best page file size, depending on the frequency of system crashes.
The Automatic memory dump feature initially selects a small paging file size. It would accommodate the kernel memory most of the time. If the system crashes again within four weeks, the Automatic memory dump feature sets the page file size as either the RAM size or 32 GB, whichever is smaller.
Kernel memory crash dumps require enough page file space or dedicated dump file space to accommodate the kernel mode side of virtual memory usage. If the system crashes again within four weeks of the previous crash, a Complete memory dump is selected at restart. This requires a page file or dedicated dump file of at least the size of physical memory (RAM) plus 1 MB for header information plus 256 MB for potential driver data to support all the potential data that is dumped from memory. Again, the system-managed page file will be increased to back this kind of crash dump. If the system is configured to have a page file or a dedicated dump file of a specific size, make sure that the size is sufficient to back the crash dump setting that is listed in the table earlier in this section together with and the peak system commit charge.
Dedicated dump files
Computers that are running Microsoft Windows or Microsoft Windows Server usually must have a page file to support a system crash dump. System administrators now have the option to create a dedicated dump file instead.
A dedicated dump file is a page file that is not used for paging. Instead, it is “dedicated” to back a system crash dump file (Memory.dmp) when a system crash occurs. Dedicated dump files can be put on any disk volume that can support a page file. We recommend that you use a dedicated dump file if you want a system crash dump but you do not want a page file.
System-managed page files
By default, page files are system-managed. This means that the page files increase and decrease based on many factors, such as the amount of physical memory installed, the process of accommodating the system commit charge, and the process of accommodating a system crash dump.
For example, when the system commit charge is more than 90 percent of the system commit limit, the page file is increased to back it. This continues to occur until the page file reaches three times the size of physical memory or 4 GB, whichever is larger. This all assumes that the logical disk that is hosting the page file is large enough to accommodate the growth.
The following table lists the minimum and maximum page file sizes of system-managed page files in Windows 10.
Minimum page file size
Maximum page file size
Varies based on page file usage history, amount of RAM (RAM Г· 8, max 32 GB) and crash dump settings.
3 Г— RAM or 4 GB, whichever is larger. This is then limited to the volume size Г· 8. However, it can grow to within 1 GB of free space on the volume if required for crash dump settings.
Performance counters
Several performance counters are related to page files. This section describes the counters and what they measure.
\Memory\Page/sec and other hard page fault counters
The following performance counters measure hard page faults (which include, but are not limited to, page file reads):
The following performance counters measure page file writes:
Hard page faults are faults that must be resolved by retrieving the data from disk. Such data can include portions of DLLs, .exe files, memory-mapped files, and page files. These faults might or might not be related to a page file or to a low-memory condition. Hard page faults are a standard function of the operating system. They occur when the following items are read:
Parts of image files (.dll and .exe files) as they are used
High values for these counters (excessive paging) indicate disk access of generally 4 KB per page fault on x86 and x64 versions of Windows and Windows Server. This disk access might or might not be related to page file activity but may contribute to poor disk performance that can cause system-wide delays if the related disks are overwhelmed.
Therefore, we recommend that you monitor the disk performance of the logical disks that host a page file in correlation with these counters. Be aware that a system that has a sustained 100 hard page faults per second experiences 400 KB per second disk transfers. Most 7,200 RPM disk drives can handle about 5 MB per second at an IO size of 16 KB or 800 KB per second at an IO size of 4 KB. No performance counter directly measures which logical disk the hard page faults are resolved for.
\Paging File(*)% Usage
The \Paging File(*)% Usage performance counter measures the percentage of usage of each page file. 100 percent usage of a page file does not indicate a performance problem as long as the system commit limit is not reached by the system commit charge, and if a significant amount of memory is not waiting to be written to a page file.
The size of the Modified Page List (\Memory\Modified Page List Bytes) is the total of modified data that is waiting to be written to disk.
If the Modified Page List (a list of physical memory pages that are the least frequently accessed) contains lots of memory, and if the % Usage value of all page files is greater than 90, you can make more physical memory available for more frequently access pages by increasing or adding a page file.
Not all the memory on the modified page list is written out to disk. Typically, several hundred megabytes of memory remains resident on the modified list.
Multiple page files and disk considerations
If a system is configured to have more than one page files, the page file that responds first is the one that is used. This means that page files that are on faster disks are used more frequently. Also, whether you put a page file on a “fast” or “slow” disk is important only if the page file is frequently accessed and if the disk that is hosting the respective page file is overwhelmed. Be aware that actual page file usage depends greatly on the amount of modified memory that the system is managing. This means that files that already exist on disk (such as .txt, .doc, .dll, and .exe) are not written to a page file. Only modified data that does not already exist on disk (for example, unsaved text in Notepad) is memory that could potentially be backed by a page file. After the unsaved data is saved to disk as a file, it is backed by the disk and not by a page file.
