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前言EMC CLARiiON CX4系列设计您的基础存储系统结构本指南介绍了采用UltraFlex技术的CLARiiON CX4系列存储系统，UltraFlex技术使CLARiiON CX4系列存储系统可在光纤通道、FCoE、iSCSI这三种不同的结构布局下工作。
设计从SAN 结构的启动与设计从光纤通道交换机结构的启动是一样的。
您应该阅读本指南：◆如果你正考虑购买这些存储系统产品并且想要了解它的特性，或◆在你计划安装这些存储系统之前。
本指南含有用于设计存储系统配置结构的工作记录表：◆硬件组件◆iSCSI 目标器（targets，即存储设备）和启动器（initiators，即主机系统）◆iSNS服务器（仅Windows环境）◆可选的iSCSI挑战握手式认证协议（CHAP）◆管理端口网络和安全登录信息◆文件系统和存储系统磁盘（LUNs和瘦LUNs）关于存储系统数据复制和数据迁移的软件配置信息（MirrorView, SnapView, SAN Copy），请使用CX4支持网站的Storage-system tasks下的Plan Configuration链接。
这些工作记录表假定你熟悉那些将要使用存储系统的服务器（主机）以及这些服务器上的操作系统。
你要为将要配置的每一个存储系统，完成一份单独的工作记录表。
要得到最流行的、最详细的和最完整的CX4系列配置规则和配置模板，请参阅Powerlink网站上的E-Lab Interoperability Navigator.确保阅读与你将要计划的配置相关的部分。
要得到存储系统有关的背景信息，阅读你的存储系统的Hardware and Operational Overview and Technical Specifications.在存储系统支持网站上的Storage-system tasks下有一个Learn about storage system链接，你可以使用这个链接下的定制文档（译者认为这个“定制文档”是一个文档生成工具）生成最新版的文档。
如何实现Linux下的U盘（USB Mass Storage）驱动How to Write Linux USB MSC (Mass Storage Class) Driver版本: 0.4作者: crifan联系方式：green-waste (at) 版本历史目录1正文之前 (6)1.1本文目的 (6)1.2阅读此文所需要的前提知识 (7)1.3声明 (7)2USB基本知识 (8)2.1USB的硬件 (8)2.2USB相关的协议 (8)2.3USB相关的软件实现 (8)3USB Mass Storage大容量存储的基本知识 (9)3.1USB Mass Storage相关的协议 (13)3.1.1USB Mass Storage相关协议简介 (14)3.1.1.1USB MSC Control/Bulk/Interrupt (CBI) Transport (14)3.1.1.2USB MSC Bulk-Only (BBB) Transport (15)3.1.1.2.1为何USB MSC中Bulk-only Transport被叫做 BBB (15)3.1.1.2.2为何已经有了CBI，又再弄出个BBB (15)3.1.1.3USB MSC UFI Command Specification (16)3.1.1.4USB MSC Bootability Specification (16)3.1.1.5USB MSC Compliance Test Specification (17)3.1.1.6USB Lockable Storage Devices Feature Specification (17)3.1.1.7USB MSC USB Attached SCSI Protocol (UASP) (17)3.1.1.7.1已有SCSI协议，为何还要再弄一个UASP (17)3.1.2USB MSC的各个协议之间关系总结 (19)3.1.3U盘与USB中的Class，Subclass和Protocol的对应关系 (20)3.1.3.1bInterfaceClass=0x08=Mass Storage (21)3.1.3.2bInterfaceSubClass=0x06=SCSI Transparent (21)3.1.3.3bInterfaceProtocol=0x50=Bulk Only Transport (21)3.2USB Mass Storage相关的软件实现 (22)4实现U盘驱动的整个流程是什么样的 (23)5Linux系统下，USB驱动的框架已经做了哪些事情 (24)6Linux下实现U盘驱动，自己需要做哪些事情以及如何做 (25)7引用文章 (26)图表图表 1 U盘 (6)图表 2 USB Mass Storage Framework (9)图表 3 PC和U盘 (10)图表 4 PC和U盘的芯片内部结构 (10)图表 5 PC和U盘的内部逻辑框图 (11)图表 6 PC和USB MSC设备 (12)图表 7 USB MSC的分类 (12)图表 8 USB Storage Class Protocol Relation (19)图表 9 SubClass Codes Mapped to Command Block Specifications (21)图表 10 Mass Storage Transport Protocol (21)图表 11 USB数据流向图 (23)缩写1 正文之前1.1 本文目的关于U盘，估计大家都用过。
Oracle Exadata Flash Cache是Oracle Exadata Database Machine上的一项功能，旨在提高数据库性能和响应速度。
它利用了固态硬盘（SSD）的高速读写性能，将其用作数据库缓存，以加快查询和数据访问速度。
具体来说，Oracle Exadata Flash Cache的工作原理如下：
1. 在Exadata Database Machine上，SSD硬盘被用作二级缓存，用于存储经常访问的数据和元数据。
2. 当数据库执行查询时，Exadata会首先检查L1和L2缓存是否包含所需的数据。
如果缓存中存在数据，则查询可以直接从缓存中读取，而不需要访问底层磁盘。
3. 如果缓存中没有所需的数据，则Exadata会使用闪存缓存来查找数据。
闪存缓存是一种快速的非易失性存储器，可以提供比传统磁盘更快的读写速度。
4. 当查询完成时，数据会被写入闪存缓存中，以便下一次查询时可以更快地访问。
总的来说，Oracle Exadata Flash Cache利用了固态硬盘的高速读写性能，将其用作二级缓存，以提高数据库性能和响应速度。
它是Oracle Exadata Database Machine的一个重要功能，可以帮助企业更好地管理和优化数据库性能。
oracleFlashback详解使用oracle数据库时,难免会碰到一些问题.例:1.如何回滚已经commit了的数据2.如何查询已经被覆盖掉的数据[update],或者被delete了的数据3.如何将数据恢复到某个时间点我们就可以使用Flashback相关语句解决相关问题了关于Flashback[回闪]:从9i到10g到最新的11.2g,oracle对Flashback功能进行了进一步的扩展,利用Flashback我们可做到1.flashback query 闪回查询,并不实际修改表的数据2.flashback table 闪回表格,可恢复表格的数据3.flash database 闪回数据库,可恢复db的数据①:关于Flashback Query:1.Flash Query通过undo数据表空间数据,利用一致性的方法来查找用户需要的数据2.作用范围:查找指定时间点被(delete,update)的数据只是做查找操作,如果设计恢复那么就要使用flashback table了3.相关参数:1.查询出来的数据存活时间受undo_retention(默认为900秒)影响 [目标值,该变量(秒)可以影响undo表空间产生的data存活时间,时间一到,即死亡(消失)]2.闪回时间受undo表空间大小影响[关于undo表空间的操作,另一片文章会有讲解]3.查询的仅仅是快照,并不能修改当前状态4.基本语法[两种方式,使用时间片或scn号] 使用时间片的情况比较多1.select * from 你要查询表的名字 as of timestamp [查询某一时间该表的数据]2.select * from 你要查询表的名字 as of scn 具体scn号 [关于scn号,另一篇文章会讲解]4.原理:简单的说就是将以前被修改,删除了的数据,通过开启Flashback 模式,回到我们需要回到的时间来查看数据,在undo_retention该变量设置的时间过后,该镜像数据会自动被清除.相当于查看的是一个镜像数据.一种方式是利用scn号来查看镜像数据,另一种是通过查找时间片来查询镜像数据案例1:①--创建测试flashQuery表格主要由scn号和系统日期组成create table testQuery(id number,scn number,time varchar2(20),mydate varchar2(20));②--插入测试数据beginfor i in 1..16loopinsert into testQuery values(i,dbms_flashback.get_system_change_number(),to_char (sysdate,'yyyy-mm-dd hh24:mi:ss'),'你好'||i);--插入scn号和sysdate为方便后续查询commit;--如果不实时commit,那么会在循环完后,批量提交,时间点是一样的dbms_lock.sleep(2);--使用dbms_lock.sleep 方法和java的thread睡眠是一个意思参数以秒为单位end loop;end;③--查询未修改的数据result:1 3303552 2011-01-25 11:51:33 你好12 3303556 2011-01-25 11:51:35 你好23 3303558 2011-01-25 11:51:37 你好34 3303560 2011-01-25 11:51:39 你好45 3303562 2011-01-25 11:51:41 你好56 3303564 2011-01-25 11:51:43 你好67 3303566 2011-01-25 11:51:45 你好78 3303568 2011-01-25 11:51:47 你好89 3303570 2011-01-25 11:51:49 你好910 3303572 2011-01-25 11:51:51 你好1011 3303574 2011-01-25 11:51:53 你好1112 3303576 2011-01-25 11:51:55 你好1213 3303578 2011-01-25 11:51:57 你好1314 3303580 2011-01-25 11:51:59 你好1415 3303582 2011-01-25 11:52:01 你好1516 3303584 2011-01-25 11:52:03 你好16④--查询最新的scn号[类似于check point],该scn号在每次commit时,都会自动变化[使用scn号来开启Flashback Query模式] select dbms_flashback.get_system_change_number from dual;result:3307628 --该scn号可以理解成为一个check point点.我们可以借助这个标记来回退到该scn号查询当前的数据④--修改第十条,和第十一条的数据:update testQuery tq set tq.mydate='新年快乐'where scn='3303572';commit;update testQuery tq set tq.mydate='万事如意'where scn='3303574';commit;select*from testQueryresult:1 3303552 2011-01-25 11:51:33 你好12 3303556 2011-01-25 11:51:35 你好23 3303558 2011-01-25 11:51:37 你好34 3303560 2011-01-25 11:51:39 你好45 3303562 2011-01-25 11:51:41 你好56 3303564 2011-01-25 11:51:43 你好67 3303566 2011-01-25 11:51:45 你好78 3303568 2011-01-25 11:51:47 你好89 3303570 2011-01-25 11:51:49 你好910 3303572 2011-01-25 11:51:51 新年快乐11 3303574 2011-01-25 11:51:53 万事如意12 3303576 2011-01-25 11:51:55 你好1213 3303578 2011-01-25 11:51:57 你好1314 3303580 2011-01-25 11:51:59 你好1415 3303582 2011-01-25 11:52:01 你好1516 3303584 2011-01-25 11:52:03 你好16⑤--使用scn号来进行闪回查询1.不开启Flashback模式,仅使用Flashback query语句做查询select*from testQuery as of scn 3307628result:1 3303552 2011-01-25 11:51:33 你好12 3303556 2011-01-25 11:51:35 你好23 3303558 2011-01-25 11:51:37 你好34 3303560 2011-01-25 11:51:39 你好45 3303562 2011-01-25 11:51:41 你好56 3303564 2011-01-25 11:51:43 你好67 3303566 2011-01-25 11:51:45 你好78 3303568 2011-01-25 11:51:47 你好89 3303570 2011-01-25 11:51:49 你好910 3303572 2011-01-25 11:51:51 你好1011 3303574 2011-01-25 11:51:53 你好1112 3303576 2011-01-25 11:51:55 你好1213 3303578 2011-01-25 11:51:57 你好1314 3303580 2011-01-25 11:51:59 你好1415 3303582 2011-01-25 11:52:01 你好1516 3303584 2011-01-25 11:52:03 你好162.开启Flashback模式做查询,整个db将会产生某个scn号所在时间点的镜像数据.使用dbms包开启Flashback模式:execDBMS_FLASHBACK.ENABLE_AT_SYSTEM_CHANGE_NUMBER(330 7628);现在查看表的数据:select*from testQuery as of scn 3307628;result:1 3303552 2011-01-25 11:51:33 你好12 3303556 2011-01-25 11:51:35 你好23 3303558 2011-01-25 11:51:37 你好34 3303560 2011-01-25 11:51:39 你好45 3303562 2011-01-25 11:51:41 你好56 3303564 2011-01-25 11:51:43 你好67 3303566 2011-01-25 11:51:45 你好78 3303568 2011-01-25 11:51:47 你好89 3303570 2011-01-25 11:51:49 你好910 3303572 2011-01-25 11:51:51 你好1011 3303574 2011-01-25 11:51:53 你好1112 3303576 2011-01-25 11:51:55 你好1213 3303578 2011-01-25 11:51:57 你好1314 3303580 2011-01-25 11:51:59 你好1415 3303582 2011-01-25 11:52:01 你好1516 3303584 2011-01-25 11:52:03 你好16注:此时整个DB为镜像数据.[如果单独再开启个链接,那么看到的还是真实数据而不是镜像数据];[如果中途要退出Flashback模式请使用:exec DBMS_FLASHBACK.DISABLE;]退出Flashback 模式:exec DBMS_FLASHBACK.DISABLE;select*from testQueryresult:1 3303552 2011-01-25 11:51:33 你好12 3303556 2011-01-25 11:51:35 你好23 3303558 2011-01-25 11:51:37 你好34 3303560 2011-01-25 11:51:39 你好45 3303562 2011-01-25 11:51:41 你好56 3303564 2011-01-25 11:51:43 你好67 3303566 2011-01-25 11:51:45 你好78 3303568 2011-01-25 11:51:47 你好89 3303570 2011-01-25 11:51:49 你好910 3303572 2011-01-25 11:51:51 新年快乐11 3303574 2011-01-25 11:51:53 万事如意12 3303576 2011-01-25 11:51:55 你好1213 3303578 2011-01-25 11:51:57 你好1314 3303580 2011-01-25 11:51:59 你好1415 3303582 2011-01-25 11:52:01 你好1516 3303584 2011-01-25 11:52:03 你好16以上就是使用scn号来做闪回查询了;⑥--使用时间点来进行闪回查询select*from testQuery as of timestamp to_timestamp('2011-01-25 13:25:55','yyyy-mm-dd hh24:mi:ss');做此查询要确保没有对原有表结构进行修改,如果有的话可能引发异常;select*from testQuery;result:1 3303552 2011-01-25 11:51:33 你好12 3303556 2011-01-25 11:51:35 你好23 3303558 2011-01-25 11:51:37 你好34 3303560 2011-01-25 11:51:39 你好45 3303562 2011-01-25 11:51:41 你好56 3303564 2011-01-25 11:51:43 你好67 3303566 2011-01-25 11:51:45 你好78 3303568 2011-01-25 11:51:47 你好89 3303570 2011-01-25 11:51:49 你好910 3303572 2011-01-25 11:51:51 你好1011 3303574 2011-01-25 11:51:53 你好1112 3303576 2011-01-25 11:51:55 你好1213 3303578 2011-01-25 11:51:57 你好1314 3303580 2011-01-25 11:51:59 你好1415 3303582 2011-01-25 11:52:01 你好1516 3303584 2011-01-25 11:52:03 你好16关于scn号和这个timeStamp的转换[这个可能会出问题(undo 表空间过小,无法查询到过早的数据)]scn→→timeStamp:select SCN_TO_TIMESTAMP(SCN号)as ts from dual;timeStamp→→scnselect TIMESTAMP_TO_SCN('25-1月-11 01.05.29.046000 下午')from dual;②:关于Flashback Table:1.闪回表格,可将表格的数据闪回到某个时间点2.需要开启行移动模式 [enable row movement]3.原理:Flashback Table也是利用Undo数据来恢复对象到指定时间点4.使用范围:恢复当前表及其相关对象到某个时间点5.注意点:1).闪回时间受参数undo_retention影响2).闪回时间受undo表空间大小影响3).和flashback query有差别，恢复表到以前的时间点[真实闪回,而不是镜像]6.语法:1).flashback table table_name to timestamp .... [根据时间点闪回]2).flash table table_name to scn ... [根据scn号回退,实际操作基本上不会用到]3).flashback table table_name to timestamp ... enable triggers. [创建表,开启行移动模式,用的不多]4).flashback table testFlashTable to TIMESTAMP systimestamp - interval '5' minute; [回退到几分钟之前,用的多]例:将第一条数据更新,然后进行闪回表格,得到我们以前的数据;创建新的表格测试:create table testFlashTable(id number,mydata varchar2(60));插入测试数据:insert into testFlashTable values(1,'一帆风顺'); commit;select*from testQuery;result:1 一帆风顺------等待5分钟--------让scn号飞一会,不然可能会出错删除数据:delete from testFlashTable;commit;select*from testQuery;result:无;开启行移动模式:alter table testFlashTable enable row movement;使用flashBack:[这种方法用的比较多,不小心删除了,马上就可以闪回][闪回到5分钟以前]flashback table testFlashTable to TIMESTAMP systimestamp -interval'5'minute;或者: [闪回到时间点]flashback table t to timestamp to_timestamp('2011-01-26 11:35:40','yyyy-mm-dd hh24:mi:ss');③:关于Flashback Database:1.闪回DB,可将数据库闪回到某个时间点 [需要事先配置,让oracle处于Flashback 状态]在真实环境中使用Flashback Database的场景是较少的,更多的是使用rman技术来做恢复还原需要单独开启后台进程[Recover Writer][RVWR],会额外增大oracle的开销这里就不对其做描述了.项目例子脚本，依次执行--后的脚本：--按创建时间逆序查询select * from web_log t order by create_date desc;--删除符合条件的数据--delete from web_log where create_date>to_date('2012-11-5 01:00:00','yyyy-mm-dd hh:mi:ss')--同上--delete from web_log where url='tj_fx';--闪回查询时间点前数据--select * from web_log as of timestamp to_timestamp('2012-11-03 13:25:55','yyyy-mm-dd hh24:mi:ss');--开启行移动模式--alter table web_log enable row movement--闪回恢复操作时间段前的数据--flashback table web_log to TIMESTAMP systimestamp - interval '30' minute。
Oracle Server X9-2LOracle Server X9-2L is the ideal 2U platform for databases, enterprise storage, and big data solutions. Supporting the standard and enterprise editions of Oracle Database, this server delivers best-in-class database reliability in single-node configurations. With support for up to 132.8 TB of high-bandwidth NVM Express (NVMe) flash storage, Oracle Database using its Database Smart Flash Cache feature, as well as NoSQL and Hadoop applications can be significantly accelerated. Optimized for compute, memory, I/O, and storage density simultaneously, Oracle Server X9-2L delivers extreme storage capacity at lower cost when combined with Oracle Linux, or Oracle Solaris with ZFS file system compression. Each server comes with built-in, proactive fault detection and advanced diagnostics, along with firmware that is already optimized for Oracle software, to deliver extreme reliability.Product OverviewOracle Server X9-2L is a two-socket server designed and built specifically for the demands of enterprise workloads. It is a crucial building block in Oracle engineered systems and Oracle Cloud Infrastructure. Powered by one Platinum, two Gold, or one Silver Intel® Xeon® Scalable Processor Third Generation models with up to 32 cores per socket, along with 32 memory slots, this server offers high-performance processors plus the most dense flash storage options in a 2U enclosure. Oracle Server X9-2L is the most balanced and highest performing 2U enterprise server in its class because it offers optimal core and memory density combined with high I/O throughput.In addition to optimized processing power and storage density, Oracle ServerX9-2L offers 10 PCIe 4.0 expansion slots (two 16-lane and eight 8-lane) for maximal I/O card and port density. With 576 gigabytes per second of bidirectional I/O bandwidth, Oracle Server X9-2L can handle the most demanding enterprise workloads.Oracle Server X9-2L offers best-in-class reliability, serviceability, and availability (RAS) features that increase overall uptime of the server. This extreme reliability makes Oracle Server X9-2L the best choice for single-node Oracle Database deployments in remote or branch office locations. Real-time monitoring of the health of the CPU, memory, and I/O subsystems, coupled with off lining capability of failed components, increases the system availability. Building on the firmware-level problem detection, Oracle Linux and Oracle Solaris are enhanced to provide fault detection capabilities when running on Oracle Server X9-2L. In Key FeaturesMost flash-dense andenergy-efficient 2Uenterprise-class serverTwo Intel® Xeon® Scalable Processor Third GenerationCPUsThirty-two DIMM slots with maximum memory of 2 TB Ten PCIe Gen 4 slotsUp to 216 TB SAS-3 disk storage in 12 slots instandard configurationsUp to 132.8 TB NVM Express high-bandwidth all-flashconfigurationOracle Integrated Lights Out Manager (ILOM)Key BenefitsReduce vulnerability tocyberattacksAccelerate Oracle Database, NoSQL, and Hadoopapplications using Oracle’sunique NVM Express design Satisfy demands ofenterprise applications withextreme I/O card densityIncrease uptime with built-in diagnostics and faultdetection from Oracle Linuxand Oracle SolarisIncrease storage capacity 15x compared to previousgeneration, combiningextreme compute power with Oracle Solaris and ZFScompressionMaximize system power efficiency with OracleAdvanced System CoolingMaximize IT productivity by running Oracle software onOracle hardwareaddition, exhaustive system diagnostics and hardware-assisted error reporting and logging enable identification of failed components for ease of service.To help users achieve accelerated performance of Oracle Database, Oracle Server X9-2L supports hot-swappable, high-bandwidth flash that combines with Database Smart Flash Cache to drive down cost per database transaction. In the all-flash configuration, with Oracle’s unique NVM Express design, Oracle Server X9-2L supports up to 12 small form factor NVMe drives and up to eight NVMe add-in cards, for a total capacity of 132.8 TB. This massive flash capacity also benefits NoSQL and Hadoop applications, reducing network infrastructure needs and accelerating performance with 120 GB per second of total NVMe bidirectional bandwidth.For maximizing storage capacity, Oracle Server X9-2L is also offered in a standard 12-disk configuration, with 3.5-inch large form factor disk slots accommodating high-capacity hard disk drives (HDDs). A maximum 216 TB of direct-attached storage makes Oracle Server X9-2L ideally suited as a storage server. The compute power of this server can be used to extend storage density even further with Oracle Solaris and ZFS file system compression to achieve up to 15x compression of data without significant performance impact. Oracle Server X9-2L is also well suited for other storage-dense implementations, such as video compression and transcoding, which require a balanced combination of compute power and storage capacity at the same time.Oracle Server X9-2L ships with Oracle ILOM 5.0, a cloud-ready service processor designed for today's security challenges. Oracle ILOM provides real-time monitoring and management of all system and chassis functions as well as enables remote management of Oracle servers. Oracle ILOM uses advanced service processor hardware with built-in hardening and encryption as well as improved interfaces to reduce the attack surface and improve overall security. Oracle ILOM has improved firmware image validation through the use of improved firmware image signing. This mechanism provides silicon-anchored service processor firmware validation that cryptographically prevents malicious firmware from booting. After Oracle ILOM's boot code is validated by the hardware, a chain of trust allows each subsequent firmware component in the boot process to be validated. Finally, with a focus on security assurance, using secure coding and testing methodologies, Oracle is able to maximize firmware security by working to prevent and remediate vulnerabilities prior to release. With advanced system cooling that is unique to Oracle, Oracle Server X9-2L achieves system efficiencies that result in power savings and maximum uptime. Oracle Advanced System Cooling utilizes remote temperature sensors for fan speed control, minimizing power consumption while keeping optimal temperatures inside the server. These remote temperature sensors are designed into key areas of this server to ensure efficient fan usage by organizing all major subsystems into cooling zones. This technology helps reduce energy consumption in a way that other servers cannot.Oracle Premier Support customers have access to My Oracle Support and multi-server management tools in Oracle Enterprise Manager, a critical component that enables application-to-disk system management including servers, virtual Key ValueOracle Server X9-2L is the most storage-dense, versatile two-socket server in its class for the enterprise data center, packing the optimal balance of compute power, memory capacity, and I/O capacity into a compact and energy-efficient 2U enclosure. Related productsOracle Server X9-2Oracle Server X8-8Related servicesThe following services are available from Oracle Customer Support:SupportInstallationEco-optimization servicesmachines, databases, storage, and networking enterprise wide in a single pane of glass. Oracle Enterprise Manager enables Exadata, database, and systems administrators to proactively monitor the availability and health of their systems and to execute corrective actions without user intervention, enabling maximum service levels and simplified support.With industry-leading in-depth security spanning its entire portfolio of software and systems, Oracle believes that security must be built in at every layer of the IT environment. In order to build x86 servers with end-to-end security, Oracle maintains 100 percent in-house design, controls 100 percent of the supply chain, and controls 100 percent of the firmware source code. Oracle’s x86 servers enable only secure protocols out of the box to prevent unauthorized access at point of install. For even greater security, customers running Oracle Ksplice on Oracle’s x86 servers will benefit greatly from zero downtime patching of the Oracle Linux kernel.Oracle is driven to produce the most reliable and highest performing x86 systems in its class, with security-in-depth features layered into these servers, for two reasons: Oracle Cloud Infrastructure and Oracle Engineered Systems. At their foundation, these rapidly expanding cloud and converged infrastructure businesses run on Oracle’s x86 servers. To ensure that Oracle’s SaaS, PaaS, and IaaS offerings operate at the highest levels of efficiency, only enterprise-class features are designed into these systems, along with significant co-development among cloud, hardware, and software engineering. Judicious component selection, extensive integration, and robust real-world testing enable the optimal performance and reliability critical to these core businesses. All the same features and benefits available in Oracle’s cloud are standard in Oracle’s x86 standalone servers, helping customers to easily transition from on-premises applications to cloud with guaranteed compatibility and efficiency.Oracle Server X9-2L System SpecificationsCache•Level 1: 32 KB instruction and 32 KB data L1 cache per core•Level 2: 1 MB shared data and instruction L2 cache per core•Level 3: up to 1.375 MB shared inclusive L3 cache per coreMain Memory•Thirty-two DIMM slots provide up to 2 TB of DDR4 DIMM memory•RDIMM options: 32 GB or 64 GB at DDR4-3200 dual rankInterfaces Standard I/O•One 1000BASE-T network management Ethernet port•One 1000BASE-T host management Ethernet port•One RJ-45 serial management port•One rear USB 3.0 port•Expansion bus: 10 PCIe 4.0 slots, two x16 and eight x8 slots•Supports LP-PCIe cards including Ethernet, FC, SAS and flashStorage•Twelve 3.5-inch front hot-swappable disk bays plus two internal M.2boot drives•Disk bays can be populated with 3.5-inch 18 TB HDDs or 2.5-inch 6.8 or 3.84 NVMesolid-state drives (SSDs)•PCIe flash•Sixteen-port 12 Gb/sec RAID HBA supporting levels: 0, 1, 5, 6, 10, 50, and 60 with 1GB of DDR3 onboard memory with flash memory backup via SAS-3 HBA PCIe cardHigh-Bandwidth Flash•All flash configuration—up to 132.8 TB in the all-flash configuration (maximum of12 hot-swappable 6.8 TB NVMe SSDs and eight 6.4 TB NVMe PCIe cards)NVMe functionality in 3.5-inch disk bays 8-11 requires an Oracle NVMeretimer that is installed in PCIe slot 10Systems Management Interfaces•Dedicated 1000BASE-T network management Ethernet port (10/100/1000 Gb/sec)•One 1000BASE-T host management Ethernet port (10/100/1000 Gb/sec)•In-band, out-of-band, and side-band network management access•One RJ-45 serial management portService ProcessorOracle Integrated Lights Out Manager (Oracle ILOM) provides:•Remote keyboard, video, and mouse redirection•Full remote management through command-line, IPMI, and browser interfaces•Remote media capability (USB, DVD, CD, and ISO image)•Advanced power management and monitoring•Active Directory, LDAP, and RADIUS support•Dual Oracle ILOM flash•Direct virtual media redirection•FIPS 140-2 mode using OpenSSL FIPS certification (#1747)Monitoring•Comprehensive fault detection and notification•In-band, out-of-band, and side-band SNMP monitoring v2c and v3•Syslog and SMTP alerts•Automatic creation of a service request for key hardware faults with Oracleautomated service request (ASR)Oracle Enterprise Manager•Advanced monitoring and management of hardware and software•Deployment and provisioning of databases•Cloud and virtualization management•Inventory control and patch management•OS observability for performance monitoring and tuning•Single pane of glass for management of entire Oracle deployments, including onpremises and Oracle CloudSoftware Operating Systems•Oracle Linux•Oracle SolarisVirtualization•Oracle KVMFor more information on software go to: Oracle Server X9-2L Options & DownloadsOperating Environment •Ambient Operating temperature: 5°C to 40°C (41°F to 104°F)•Ambient Non-operating temperature: -40°C to 68°C (-40°F to 154°F)•Operating relative humidity: 10% to 90%, noncondensing•Non-operating relative humidity: up to 93%, noncondensing•Operating altitude: Maximum ambient operating temperature is derated by 1°C per 300 m of elevation beyond 900 m, up to a maximum altitude of 3000 m•Non-operating altitude: up to 39,370 feet (12,000 m)•Acoustic noise-Maximum condition: 7.1 Bels A weightedIdle condition: 7.0 Bels A weightedConnect with usCall +1.800.ORACLE1 or visit . Outside North America, find your local office at: /contact. /oracle /oracleCopyright © 2023, Oracle and/or its affiliates. All rights reserved. This document is provided for information purposes only, and the contents hereof are subject to change without notice. This document is not warranted to be error-free, nor subject to any other warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. We specifically disclaim any liability with respect to this document, and no contractual obligations are formed either directly or indirectly by this document. This document may not be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without our prior written permission.This device has not been authorized as required by the rules of the Federal Communications Commission. 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vue3 storag 用法【Vue3 Storage用法】中括号是JavaScript中的一种语法符号，用于访问对象的属性值。
在Vue3中，可以使用中括号来访问和操作Storage对象。
本文将逐步介绍Vue3 Storage 的用法，包括基本概念、操作方法和实例演示。
一、基本概念1.1 Vue3 Storage简介Vue3 Storage是Vue3官方提供的一个插件，用于在浏览器端进行数据的存储和读取。
它利用浏览器提供的localStorage和sessionStorage API，实现了数据的持久化存储和临时存储功能。
1.2 Storage对象的类型Vue3 Storage主要有两种类型：localStorage和sessionStorage。
localStorage用于持久化存储数据，存储的数据在浏览器关闭后仍可保留；sessionStorage用于临时存储数据，存储的数据只在当前会话中有效，在浏览器关闭后会被清除。
1.3 Storage对象的方法Vue3 Storage提供了一系列方法来进行数据的操作，包括set、get、remove 和clear等。
这些方法可以通过中括号来调用。
二、操作方法2.1 安装Vue3 Storage首先，在Vue3项目中安装Vue3 Storage插件。
可以通过npm命令进行安装：npm install vue3-storage安装完成后，在main.js文件中引入和使用Vue3 Storage插件：javascriptimport { createApp } from 'vue'import Vue3Storage from 'vue3-storage'const app = createApp(App)e(Vue3Storage)app.mount('#app')2.2 设置数据使用Vue3 Storage插件的set方法来设置一个数据项。
oracle exadata flash 原理Oracle Exadata是一种专为Oracle 数据库设计的高性能硬件和软件解决方案，而 Exadata Flash 是其一部分，指的是采用固态闪存技术作为存储介质的一种存储层面的优化。
Exadata Flash 带来了更高的 I/O 性能和更低的存储延迟，提高了数据库系统的整体性能。
以下是 Oracle Exadata Flash 的一些基本原理：1. 智能存储技术： Exadata Flash 采用智能存储技术，其中存储服务器（Storage Servers）上的闪存设备直接与数据库服务器（Database Servers）通信。
这使得存储层能够更加智能地处理数据库请求，降低数据库服务器和存储服务器之间的数据传输负担。
2. 存储跨节点协调： Exadata 采用了存储服务器协调技术，允许存储服务器之间协同工作，共同处理查询和数据操作。
这种协调有助于减少数据传输和提高并行性，尤其是在多节点配置的 Exadata 系统中。
3. 智能存储索引和过滤：Exadata Flash 使用智能存储索引，可以在存储层面进行数据过滤和查询优化，减少了数据库服务器端的数据传输。
这有助于减轻数据库服务器的工作负担，提高查询性能。
4. 闪存写优化： Exadata Flash 采用了优化的写入算法，减少了写入操作对闪存的影响，提高了写入性能。
这对于OLTP（联机事务处理）等需要高度写入性能的工作负载尤其重要。
5. 存储压缩和列式存储： Exadata 采用了存储压缩和列式存储技术，可以显著减小存储占用空间，提高数据传输效率。
这对于处理大量数据的数据仓库工作负载非常有益。
总体而言，Oracle Exadata Flash 利用先进的存储技术，通过智能存储、存储协调、存储索引、优化的写入算法等手段，提高了Oracle 数据库系统在存储层面的性能和效率。
这些优化有助于满足不同工作负载的需求，包括 OLTP、数据仓库等。
oracle flash back原理Oracle Flashback是一种数据库恢复和查询技术，它可以基于时间或者特定条件，将数据库恢复到过去的某个状态。
本文将详细介绍Oracle Flashback的原理和实现方式。
现代数据库面临着日益增长的数据量和日志的快速变化。
数据库管理员需要能够在数据损坏或删除时快速恢复数据库，并且能够进行详细的查询和分析操作。
Oracle Flashback技术提供了一种可靠且高效的解决方案，使管理员能够快速恢复数据库，追溯数据变更历史和查询特定时刻的数据状态。
【1. Oracle Flashback的基本原理】Oracle Flashback的原理是通过使用Undo数据和Redo数据来实现数据的恢复和查询。
Undo数据是事务发生前的数据副本，也称为回滚段。
当一个事务发生时，Oracle数据库将当前的数据状态复制一份，称为Undo数据。
在事务执行过程中，所有的修改操作都是在Undo数据上进行的，并且还会保存被修改的数据的一个副本。
这样，当需要恢复到过去的某个时刻时，可通过Undo数据将数据库还原到该时刻的状态。
Redo数据是在数据库中发生修改操作时，记录这些操作的数据。
当数据库发生故障或者需要进行恢复时，通过Redo数据可以将数据库恢复到最近的一次备份或者故障前的状态。
【2. Oracle Flashback的实现方式】Oracle提供了多种方式来实现Flashback技术，包括Flashback Query、Flashback Transaction、Flashback Table、Flashback Database等。
下面分别介绍这些实现方式的原理和使用方法。
(1) Flashback QueryFlashback Query是一种基于时间点查询的技术，可以在一个事务中查询到过去某个时间点的数据库状态。
它通过读取Undo数据和Redo 数据，将数据库恢复到指定时间点的状态，然后执行查询操作。
Oracle的闪回恢复区和归档⽇志多路径设置Oracle9i开始提供闪回查询，以便能在需要的时候查到过去某个时刻的⼀致性数据，这是通过Undo实现的。
这个功能有很⼤的限制，就是相关事务的undo不能被覆盖，否则就⽆⼒回天了。
oracle10g⼤⼤的增强了闪回查询的功能，并且提供了将整个数据库回退到过去某个时刻的能⼒，这是通过引⼊⼀种新的flashback log实现的。
flashback log有点类似redo log，只不过redo log将数据库往前滚，flashback log则将数据库往后滚。
为了保存管理和备份恢复相关的⽂件，oracle10g提供了⼀个叫做闪回恢复区(Flashback recovery area)的新特性，可以将所有恢复相关的⽂件，⽐如flashback log,archive log,backup set等，放到这个区域集中管理。
1.设置闪回恢复区闪回恢复区主要通过3个初始化参数来设置和管理db_recovery_file_dest ：指定闪回恢复区的位置db_recovery_file_dest_size ：指定闪回恢复区的可⽤空间⼤⼩db_flashback_retention_target ：指定数据库可以回退的时间，单位为分钟，默认1440分钟，也就是⼀天。
当然，实际上可回退的时间还决定于闪回恢复区的⼤⼩，因为⾥⾯保存了回退所需要的flash log。
所以这个参数要和db_recovery_file_dest_size配合修改。
2.启动flashback database设置了闪回恢复区后，可以启动闪回数据库功能。
⾸先，数据库必须已经处于归档模式1.关闭数据库SQL> shutdown immediate;2.启动数据库为mount模式SQL> startup mount3.显⽰和修改归档模式SQL> archive log listSQL> alter database archivelog;SQL> alter database open4.设置归档⽇志的格式SQL>alter system set log_archive_format='ARC%s%t%r.log' scope=spfile;5.设置归档⽇志的存放路径SQL>alter system set log_archive_dest='+data/arcl' scope=spfile;SQL>shutdown immediateSQL>startup6.强制切换归档⽇⾄SQL>alter system switch logfile;7.取消归档SQL>alter database noarchivelog;参数1.格式参数%s⽇志序列号%S⽇志序列号（带前导的0）%t重做线程编号%a活动的ID号%d数据库ID号%r RESELOGS的iD值SQL> archive log list;Database log mode Archive ModeAutomatic archival EnabledArchive destination USE_DB_RECOVERY_FILE_DESTOldest online log sequence 156Next log sequence to archive 158Current log sequence 158然后，启动数据库到mount状态SQL> shutdown immediate;Database closed.Database dismounted.ORACLE instance shut down.SQL> startup mountORACLE instance started.Total System Global Area 285212672 bytesFixed Size 1218992 bytesVariable Size 75499088 bytesDatabase Buffers 205520896 bytesRedo Buffers 2973696 bytesDatabase mounted.SQL>alter database flashback on;数据库已更改。
