The I/O Frame, running a customized Linux operating system, provides the main input and output connections for the Q-SYS system. The Core connects to the I/O Frame via the Q-SYS network, limiting the number of I/O Frames only to the size of your Core, and network bandwidth. An I/O Frame can contain up to four of the five available Audio I/O cards.
Type 2 hardware provides new cables and connectors between the I/O cards and main boards in Cores and I/O Frames. Due to this change, the Type 2 hardware is not physically compatible with the older hardware. You can still integrate the new I/O Frames and Cores in the same system with older hardware, but the I/O cards are not interchangeable. Type 2 hardware can be identified by a yellow label on the back of the Core and I/O Frame, and the bottom of the I/O cards.
Insert a paperclip or similar device into the reset hole and hold for 10 seconds. A timer displays on the LCD. This resets all network settings to their factory defaults: IP Addresses, hostname, etc.
In this article, we will discuss how to resolve I/O problems that is a very important point for the SQL Server troubleshooting. The storage subsystem is one of the significant performance factors for the databases. Detecting and identifying I/O problems in SQL Server can be a tough task for the database administrators (DBAs). Generally, the underlying reasons for the I/O problems can be:
Analyzing the symptoms should be a major principle to clarify the underlying reason that causes the I/O issues on SQL Server. Otherwise, we can waste time dealing with irrelevant issues or discussing the issues with system or storage administrators unnecessarily. Wait types give very useful information for SQL Server troubleshooting. The following wait types can indicate I/O problems, but these wait types do not suffice to decide any problem on the disks.
SQL Server reserves an area on the memory to itself, and this area uses to cache data and index pages to reduce the disk activities. This reserved memory area is called Buffer Pool. The working mechanism of the buffer pool is very simple; the data loads from the disk to the memory when any request has been received for reading or changing, and they process in the buffer pool. The data is written to the disk again when it is modified. In light of this information, PAGEIOLATCH_* occurs when transferring data from disk to buffer pool. It is very normal to detect some PAGEIOLATCH_* however, it indicates a problem when we see this wait type frequently and more than the other wait types. PAGEIOLATCH_* does not indicate disk problems by oneself because this wait type can occur for a variety of reasons. For example:
When any modification is performed in the database, SQL Server writes this modification to log buffer, and then it writes this buffer data to disk. Therefore, this wait type is related to the physical disk that contains the log file (ldf). Placing log files (ldf) on as fast and dedicated disks as possible will be the right approach to overcome these problems. At the same time, performance statistics of physical disks that store ldf files should be considered when this problem occurs. The log data is written into the disk sequentially, and the reading process is also performed sequentially. Due to this working principle, the disks selected for the log files must perform well for the sequential read and write throughput along with the minimum latency.
This wait type occurs when the SQL Server processes backup and restore operations; however, when this operation takes more time than usual, it might be a warning for the I/O problems. The BACKUPIO can be seen with the ASYNC_IO_COMPLETION so we can consider about any disk problem.
I/O stall time is an indicator that can be used to detect I/O problems. The dm_io_virtual_file_stats is a dynamic management function that gives detailed information about the stall times of the data and log files so it will simplify the SQL Server troubleshooting process. This dynamic management function takes two parameters first one is database id, and the second one is the database file number.
The high stall times indicate I/O problems and busy disk activities. With the help of the following query, we can find out the read, write, and total latency of the database files so that we can diagnose any storage problems.
The Average Total Latency column represents the total latency about the database files, and we can use the following table as reference to evaluate the disk performance against latency.
Performance Monitor is also known as Perfmon and this tool helps to track metrics about computer resources or installed applications. Particularly, Perfmon assists in analyzing and troubleshooting SQL Server performance problems because It includes some particular counters for SQL Server beside the general resource counters. We can understand that Perfmon plays a key role in the SQL Server troubleshooting according to this explanation. When we focus on the I/O counters of the Perfmon, some of them come to the forefront. First of all, we should keep on eye to latency metrics because these values can tell everything about the disk performance.
The throughput metric indicates how much MB can be read or written by the disk subsystems per second. The throughput value will be changed according to our disk infrastructure, types, and vendors. For this reason, the exact value could not be given for this counter.
In this article, we learned the basic methods that help to diagnose and troubleshoot SQL Server I/O problems. To overcome this type of problem, we need to observe all metrics that can be helped to figure out the main problem. Understanding the main problem is a very significant point for the SQL Server troubleshooting.
Esat Erkec is a SQL Server professional who began his career 8+ years ago as a Software Developer. He is a SQL Server Microsoft Certified Solutions Expert. Most of his career has been focused on SQL Server Database Administration and Development. His current interests are in database administration and Business Intelligence. You can find him on LinkedIn.View all posts by Esat Erkec
The following administrative user accounts are automatically created when you install Oracle Database. They are both created with the password that you supplied upon installation, and they are both automatically granted the DBA role.
This account can perform all administrative functions. All base (underlying) tables and views for the database data dictionary are stored in the SYS schema. These base tables and views are critical for the operation of Oracle Database. To maintain the integrity of the data dictionary, tables in the SYS schema are manipulated only by the database. They should never be modified by any user or database administrator. You must not create any tables in the SYS schema.
While this account can be used to perform day-to-day administrative tasks, Oracle strongly recommends creating named user accounts for administering the Oracle database to enable monitoring of database activity.
This week at work, an engineer mentioned that they were looking at the sizesof data returned by an API, and it was always coming out the same, which seemedstrange. It turned out the data was a dict, and they were looking at the sizewith sys.getsizeof.
I noticed two big (~ 2GB) files (hiberfil.sys and pagefile.sys) at the root of my C: drive and wondered what they were. I searched on google and found some interesting links, but did not find any answer on this site. I guess it would be good to have this question answered here for future reference.
hiberfil.sys: is a file used by Windows when you choose to 'Hibernate' the system. Take a look at this site on how to delete it, if you won't use the Hibernate option. In short, you run powercfg -h off in a command terminal with administrator privileges. The file should then be automatically deleted, and the Windows hibernation feature disabled.
Can you delete them? Yes, but not by simply going to the Windows Explorer and removing them. Take a look at the provided links, or do some research about your Windows version, to know how to delete them.
hiberfil.sys is the hibernation file, where Windows writes the contents of your system's memory when it hibernates. I believe that should be safe to delete while your system is running, but I'd like to get confirmation from someone who knows Windows better before you do anything.
pagefile.sys is the, well, pagefile, analogous to the swap partition on Linux (if that helps at all). The system uses it for extra memory when it runs out of space in RAM (it 'pages' it out to this file, thus 'pagefile'). It's extremely (relative to RAM) slow, but usually better than running out of memory altogether. You should NOT delete this file, at least while the system is running.
hiberfil.sys is a file the system creates when the computer goes into hibernation mode. Hibernate mode uses the hiberfil.sys file to store the current state (memory) of the PC on the hard drive and the file is used when Windows is turned back on. In Hibernate mode the PC power is down entirely, so you can even take the battery out, put it back in, and be right back where you were. hiberfil.sys is a hidden file. It means that you could see it in windows file manager only if you checked 'Show hidden files and folders' in Folder Options.
The Know Your Data Portal (formerly EDStats) provides access to interactive reports that deliver overall and demographic information in a variety of formats, including charts, tables, and maps that can be customized and downloaded as an Image, Crosstab, PDF, or PowerPoint file. School- and district-level disaggregations for the High School Graduation Rates and for High School Graduate Pathways may be obtained via the PK-12 Advanced Reports section of the Know Your Data tool.
School- and district-level disaggregations for grades K-5 courses, grades 6-12 courses, exceptional student education (ESE) courses, and dual enrollment courses may be obtained via the Course Enrollments, PK-12 Advanced Reports section of the Know Your Data tool. 2b1af7f3a8