megabytes and kilobytes

The free command displays the idle, used physical memory and swap memory in the Linux system, and the buffer used by the kernel. In Linux system monitoring tools, the free command is one of the most frequently used commands.1. Command format:free [parameters]2. Command function:The free command displays system usage and idle memory conditions, including physical memory, interactive area memory (swap), and kernel buffer memory. Shared memory will be ignored3. Command parameters:-B Displays memory

core indicators, these indicators can let us understand the system state in more detail. The following parameter, 1, indicates that the statistics are output once per second, and the header hints at the meaning of each column, which describes some of the columns related to performance tuning:R: The number of processes waiting on CPU resources. This data is more capable of showing CPU load than the average load, and the data does not contain the process of waiting for IO. If this value is greate

that the eth0 outlet has 100mbit/s bandwidth, assigned to WWW, e-mail and Telnet three data traffic, which is allocated to the WWW bandwidth of 40mbit/s, the bandwidth allocated to the email is 40mbit/s, the bandwidth allocated to Telnet is 20Mbit SIt is important to note that the following abbreviations are used in the TC to indicate the appropriate bandwidth:Kbps kiiobytes per second, or "kilobytes per second;Mbps

. The following suffixes can be used: b for 512-byte blocks (here is the ' default if no suffix is used) C for bytes W for two-byte words K for kilobytes (Units of 1024 bytes) M for megabytes (units of 1048576 bytes) G for gigabytes (units of 1073741824 bytes) Note: The default unit is B, and it represents 512 bytes, so 2 means that 1k,1m is 2048, if you do not want to convert, you can use other unit

. Assigning temporary table space to users A temporary table space, as the name suggests, is a temporary segment of a user object that temporarily holds tables, indexes, and so on. Create a method like Assigning a user quota to a table space Use quotas to limit the number of disks that users use in a table space. Quotas can be made in bytes, kilobytes, megabytes, or unrestricted. Assign a summary to

./test21.5M.[Maple@linux ~]$ Supplemental Note : du displays the disk space occupied by the specified directory or file. ParametersA or-all displays the size of individual files in the directory.-B or-bytes displays the directory or file size in bytes.-C or--total displays the sum of all directories or files in addition to the size of individual directories or files.-D or--dereference-args displays the source file size for the specified symbolic connection.-H or--human-readable to k,m

Command use The Du (disk usage) command calculates the disk space that a file or directory occupies. When you do not specify any options, it measures the current working directory and all its subdirectories, showing the number of directories that are accounted for by each directory, and then displays the total speed of the working directory. Command format Du [OPTION] ... [FILE] ... -a,–all Includes all the files, not just directories. –apparent-size Print apparent sizes, rather than disk

Base the size of each file on the size of Rfile -S size --size=size adjusts the size of the file ' KB ' according to the options below > 1000 (kilobytes) ' K ' => 1024 (kibibytes) ' MB ' => 1000*1000 (megabytes) ' M ' => 1024*1024 (mebi Bytes) ' GB ' => 1000*1000*1000 (gigabytes) ' G ' => 1024*1024*1024 (gibibytes) or a unit such as T P E Z is based on the following The symbol of the face, depending

, you get the exact value; For example, the considered as bytes, not megabytes or kilobytes. -xxaggressive -xx:allocchunksize -xx:+|-checkjnicalls -xx:+|-checkstacks -xxcompaction -xxcompactratio (deprecated) -xxcompactsetlimit (deprecated) -xxcompactsetlimitperobject (deprecated) -xxcompressedrefs -xx:+|-crashonoutofmemoryerror -xx:+|-disableattachmechanism -xxdumpfullstate -xxdumpsize -xx:exceptiontracefi

, complete recovery Rman> Run {2> allocate channel DEV1 type disk; 3> SQL "ALTER DATABASE mount"; 4> restore datafile 2; 5> re Store DataFile 3; 6> restore Archivelog all; 7> Recover database; 8> SQL "ALTER DATABASE OPEN"; 9> release channel Dev1; 10>} 11. Script To create or replace a script: Rman> Create script Alloc_disk {2> # Allocates one disk 3> allocate channel DEV1 type disk; 4> Setlimit Chann El dev1 Kbytes 2097150 maxopenfiles readrate 200; 5>}rman> Replace script rel_disk {2> # relea

tablespace User_data;　　ALTER USER Manoj temporary tablespace dev1_data; Use quotas to allocate table spaces to users limit the number of users using the disk in the table space. Quotas can be made in bytes, kilobytes, megabytes, or unrestricted. CREATE USER Piyush identified by Saraswatidefault tablespace User_dataquota Unlimited on User_dataquota 20M on tools;　　ALTER USER Manoj QUOTA 2500K on tools; Assig

be used for the static resource. If not specified, the default value of the flag is true. This value can be changed while the Web application is running (for example, through JMX). When caching is disabled in the cache, any resources are currently purged from the cache.Cachemaxsize: The maximum size of the static resource cache in kilobytes. If not specified, the default value is 10240 (10 megabytes). This

automatically creates a locally managed tablespace with automatic segment space management.Can, but need not, specifyEXTENTMANAGEMENTLOCALandSEGMENTSPACEMANAGEMENTAUTOIn this statement. However, the database returns an error if you specifyEXTENTMANAGEMENTDICTIONARYOrSEGMENTSPACEMANAGEMENTMANUAL. The remaining syntax of the statement are the same as for theCREATE TABLESPACEStatement, but can only specify one data file. For example:CREATE bigfile tablespace bigtbs datafile '/u02/oracle/data/b

startup and after startup.Set scope: Global and Reply level, the global level requires Super permissions, and session level only affects the session itself.Setup method: Can be modified by configuration file and startup option before starting, set by the SET clause after startup.Effective period: Global variables are globally visible, but only affect the client that initializes the corresponding session variable from the global variable after the change. The current session and the logged-on se

a global variable can see changes to the global variable. However, it only affects clients that are connected after a change to initialize the corresponding session variable from that global variable. It does not affect the session variables of the clients that are already connected (even the client that executes the SET global statement).When you use the startup option to set a variable, the variable value can use the suffix K, m, or G to represent kilobyt