Amazon EFS - Cloud File Storage. Amazon Elastic File System (Amazon EFS) provides simple, scalable file storage for use with Amazon EC2 instances in the AWS Cloud. Amazon EFS is easy to use and offers a simple interface that allows you to create and configure file systems quickly and easily. With Amazon EFS, storage capacity is elastic, growing and shrinking automatically as you add and remove files, so your applications have the storage they need, when they need it. When mounted to Amazon EC2 instances, an Amazon EFS file system provides a standard file system interface and file system access semantics, allowing you to seamlessly integrate Amazon EFS with your existing applications and tools. Multiple Amazon EC2 instances can access an Amazon EFS file system at the same time, allowing Amazon EFS to provide a common data source for workloads and applications running on more than one Amazon EC2 instance. It’s designed for high availability and durability, and provides performance for a broad spectrum of workloads and applications, including Big Data and analytics, media processing workflows, content management, web serving, and home directories. Step-by-step tutorial on how to deploy your Windows Server 2012 R2 NFS server. Use it to easily connect Linux and Unix-based clients or servers to your Windows file storage. Troubleshooting NFS Problems. The first thing is to determine with one version of protocol you encounter the. Is this NFS3 and NFS4? For example RHEL 6 by default uses NFS4 for mounting. RHEL 6 systems. So you can get NFS4 mount even if you do not suspect specifying. NFS4 explicitly. This is due to the fact that nfs. NFS4 not NFS3 like before. FirePlotter, Fire Plotter, real-time, real time, firewall, sessions, connection, analyser, analyzer, monitor, connections, monitoring, bandwidth, quality of service, qos, throtttling, port, ports, usage, cisco, pix, asa. 5.5.1 Direct NFS Client. With Oracle Database 11 g, you can store data files on a supported NFS system. You can configure Oracle Database to access NFS V3 servers directly using an Oracle internal Direct NFS Client. This is the latest version of the Oracle RAC 12c (12.1.0.2) Operational Best Practices presentation as shown during IOUG / Collaborate15. As best practices are Shared file storage for the AWS cloud, supporting a file system interface and file system semantics for thousands of Amazon EC2 instances. A Network File System (NFS) allows remote hosts to mount file systems over a network and interact with those file systems as though they are mounted locally. This enables system administrators to consolidate resources onto. Venkateswararao Jujjuri (JV) File systems and Storage Architect IBM Linux Technology center [email protected]. It's comely opposite with NFS4. NFS 4 is much more complex and less reliable. For example. NFS4 often demonstrate spontaneous problem with mount points, when umount operation. It is very difficult to. RHEL 6 and derivatives without rebooting the server. NAME monitorix.conf - Configuration file for Monitorix. CONTENTS Description Configuration Options Built-in HTTP server Built-in HTTP server with access authentication Log files pathnames Piwik tracking code. File level storage is usually accessible using common file level protocols such as SMB/CIFS (Windows) and NFS (Linux, VMware). In the block level world, you need to create a volume, deploy an OS, and then attach to the created. If problem disappears that. NFS3. So everywhere below NFS means NFS3. For. example NFS 4 is more picky and can mount directories with nobody: nobody. NFS3 mounts it correctly. See nfsv. 4 mounts files. Most problem with NFS3 are not connected with protocol per se, but more like. Time Synchronization. NFS does not synchronize time between client and server, and offers no mechanism. What this means. is that a client can update a file, and have the timestamp on the file be either. Of even greater. importance is the affect on programs. Programs often do not expect time difference. Poor time synchronization also makes debugging problems difficult, because. This is especially. Use of NTP can result in machines that. Note: The NFS protocol version 3 does have support for the client. File Locking Semantics. Programs use file locking to insure that concurrent access to files does. This prevents data corruption. In Unix, the kernel handles file locking. This is required so that if a program. It also allows the operations. In an effort to solve this, a separate server, the lock daemon, was. Typically, each NFS server will run a lock daemon. The combination of lock daemon and NFS server yields a solution that is almost. Unix file locking. Unfortunately, file locking is extremely slow, compared. NFS traffic without file locking (or file locking on a local Unix disk). In the event of server failure (e. However, the clients are not informed of this, and. In the event of client failure, the locks are not immediately freed. Nor. is there a timeout. If the client process terminates, the client OS kernel will. However, if the client system. When the client reboots and remounts the NFS exports. If the client does not reboot, for example if a frustrated user hits the. Workaround: If possible (given program source and skill with code. Otherwise, build platforms never fail and have a staff trained. NFS file locking failure. If NFS is used only for files. However, clients may chose. File Locking APIIn Unix, there are two flavours of file locking, flock() from BSD. System V. It varies from system to system which of. NFS. In Solaris, Sun's Unix variant, lockf(). NFS, and flock() is implemented via lockf(). On. other systems, the results are less consistent. For example, on some systems. NFS; while on other systems, lockf() supports NFS but flock(). Regardless of the system specifics, programs often assume that if they are. This can. cause problems as programs wait for the lock to be freed. Since the reason the. This results in either the applications waiting forever, or aborting. These results will also vary with the support of the server. While typically. the NFS server runs an accompanying lock daemon, this is not guaranteed. Workaround: Upgrade to the latest versions of all operating systems. Also, use. the lock daemon. Additionally, try to use only programs written to handle NFS. Exclusive File Creation. In Unix, when a program creates a file, it may ask for the operation to fail. This allows programs to know that, for example, they have a. It is also used by various daemons for. Unfortunately, NFS does not properly implement this behaviour. A file creation. will sometimes return success even if the file already exists. Programs written. I have personally seen mailboxes with hundreds of mail. Workaround: If possible (given program source and skill with code. Linux open(). manual page: The solution for performing atomic file locking using a lockfile is. Do not use the. return value of the link() call. This still leaves the issue of client failure unanswered. The suggested solution. Delayed Write Caching. In an effort to improve efficiency, many NFS clients cache writes. This means. that they delay sending small writes to the server, with the idea that if the. The. difference is that Unix servers also keep track of the state of the file in. In NFS caching, all applications on a single client will typically see the. However, applications accessing the file from different. Workaround: It is often possible to disable client write caching. Read Caching and File Access Time. Unix file systems typically have three times associated with a file: the time. NFS file systems also report this information. Reading small. amounts of data does not update the access time on the server. This means a. server may report a file has been unaccessed for a much longer time than is. This can cause problems as administrators and automatic cleanup software. Workaround: Attribute caching may be disabled on the client, but this. Administrators should be. NFS regarding file access time. Any programs. that rely on access time information should be modified to use another mechanism. Indestructible Files. In Unix, when a file is opened, the data of that file is accessible to the process. The disk blocks the file uses are. Indeed, in NFS clients never really . So when a. file is deleted, the server merely frees the space. Woe be unto any client that. Unix world! If it does, the client renames the file to a . Any read. or write requests from processes on the client that were to the now- deleted. This file is named in the form . XXXX, where the XXXX. These files are difficult to get rid of, as the process with the file open. These. files may have unpleasant side effects such as preventing directories from being. If the server or client crashes while a . XXXX file is in use. There is no way for the server or a client to know. XXXX file is currently being used by a client or not. It would be best to exit or kill processes using an NFS file before. Unfortunately, there is no way to know if an uncooperative process. User and Group Names and Numbers. NFS uses user and group numbers, rather than names. This means that each machine. NFS export needs (or at least should) have the same user and. NFS export has. Note that this problem is not unique. NFS, and also applies, for instance, to removable media and archives. It. is most frequently an issue with NFS, however. Superuser Account. NFS has special handling of the superuser account (also known as the root account). When an NFS. drive has been mounted, this is no longer the case. This can confuse scripts. To clarify: a normal user (for example . Workaround: Enable root access to specific clients for NFS exports. NFS is insecure. Therefore, this does. FAIR USE NOTICE This site contains. We are making such material available. We believe this constitutes a 'fair use' of any such. US Copyright. Law. In accordance with Title 1. U. S. C. Section 1. Multiple types of probes increase this period.
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