Introduction to Automatic Storage Management (ASM)
Data Disk Failure, Heartbeats and Re-Replication; Cluster Rebalancing HDFS exposes a file system namespace and allows user data to be stored in files. brands — to bring digital creations to life and deliver them to the right person What kind of data can an application that runs in Flash Player store on my computer? I've already set privacy and disk space options in my browser. relation to any other Internet privacy or security settings you may have set in your browser. Database Storage Administrator's Guide . For information about failure groups, refer to "Understanding ASM Concepts" and "ASM of two failure groups controller1 or controller2 with four disks in each failure group. to delay the drop operation by specifying a time interval to repair the disk and bring it back online.
The Supervisor  handled non-equivalence interruptions [c] and managed the transfer of pages between core and drum in order to provide a one-level store  to programs.
SWP for use as a swap file. If the user moves or deletes this file, a blue screen will appear the next time Windows is started, with the error message "The permanent swap file is corrupt".
The user will be prompted to choose whether or not to delete the file whether or not it exists. Windows automatically sets the size of the page file to start at 1. If a user runs memory-intensive applications on a system with low physical memory, it is preferable to manually set these sizes to a value higher than default. The default location of the page file is in the root directory of the partition where Windows is installed. Windows can be configured to use free space on any available drives for pagefiles.
It is required, however, for the boot partition i. Windows uses the paging file as temporary storage for the memory dump. When the system is rebooted, Windows copies the memory dump from the pagefile to a separate file and frees the space that was used in the pagefile.
Please update this article to reflect recent events or newly available information. July In the default configuration of Windows, the pagefile is allowed to expand beyond its initial allocation when necessary. If this happens gradually, it can become heavily fragmented which can potentially cause performance problems. The fragmentation of the pagefile that occurs when it expands is temporary.
As soon as the expanded regions are no longer in use at the next reboot, if not sooner the additional disk space allocations are freed and the pagefile is back to its original state. Locking a pagefile size can be problematic if a Windows application requests more memory than the total size of physical memory and the pagefile, leading to failed requests to allocate memory that may cause applications and system processes to fail. Also, the pagefile is rarely read or written in sequential order, so the performance advantage of having a completely sequential page file is minimal.
However, a large pagefile generally allows use of memory-heavy applications, with no penalties beside using more disk space. While a fragmented pagefile may not be an issue by itself, fragmentation of a variable size page file will over time create a number of fragmented blocks on the drive, causing other files to become fragmented.
Rupture disc - Wikipedia
For this reason, a fixed-size contiguous pagefile is better, providing that the size allocated is large enough to accommodate the needs of all applications. The required disk space may be easily allocated on systems with more recent specifications i. In both examples the system is using about 0. Defragmenting the page file is also occasionally recommended to improve performance when a Windows system is chronically using much more memory than its total physical memory.
In general, performance concerns related to pagefile access are much more effectively dealt with by adding more physical memory. Unix and Unix-like systems[ edit ] Unix systems, and other Unix-like operating systems, use the term "swap" to describe both the act of moving memory pages between RAM and disk,[ citation needed ] and the region of a disk the pages are stored on.
In some of those systems, it is common to dedicate an entire partition of a hard disk to swapping. These partitions are called swap partitions. Many systems have an entire hard drive dedicated to swapping, separate from the data drive scontaining only a swap partition.
A hard drive dedicated to swapping is called a "swap drive" or a "scratch drive" or a " scratch disk ". Some of those systems only support swapping to a swap partition; others also support swapping to files. Swap partitions on SSDszswapand zram The Linux kernel supports a virtually unlimited number of swap backends devices or filessupporting at the same time assignment of backend priorities.Disc Store Unboxing
When the kernel needs to swap pages out of physical memory, it uses the highest-priority backend with available free space. If multiple swap backends are assigned the same priority, they are used in a round-robin fashion which is somewhat similar to RAID 0 storage layoutsproviding improved performance as long as the underlying devices can be efficiently accessed in parallel. To increase performance of swap files, the kernel keeps a map of where they are placed on underlying devices and accesses them directly, thus bypassing the cache and avoiding filesystem overhead.
However, the administrative flexibility of swap files can outweigh certain advantages of swap partitions. For example, a swap file can be placed on any mounted file system, can be set to any desired size, and can be added or changed as needed. Swap partitions are not as flexible; they cannot be enlarged without using partitioning or volume management tools, which introduce various complexities and potential downtimes. Swappiness[ edit ] Swappiness is a Linux kernel parameter that controls the relative weight given to swapping out of runtime memoryas opposed to dropping pages from the system page cache.
Swappiness can be set to values between 0 and inclusive. A low value causes the kernel to avoid swapping; a higher value causes the kernel to try to use swap space. The default value is 60; setting it higher will increase performance of "hot" processes at the cost of making a return to inactive "cold" ones take a long pause, while setting it lower even 0 may decrease response latency.
Systems with more than adequate RAM for any expected task may want to drastically lower the setting. When every process is waiting on the swap, the system is considered to be in swap death. The default and Apple-recommended installation places them on the root partition, though it is possible to place them instead on a separate partition or device. It still uses flat shared address space that cannot be defragmented. I am a very lucky man. No one sets out to annoy or upset the other person.
Such actions are the literal kiss of death to any affair of the heart. Mostly complacency, and laziness, in my own case. Disc Golf can easily kill a relationship — even a strong one The first thing to recognise is that over time the non-golfing partner is liable to start thinking disc golf is more important than they are. This is because the golf-obsessed person does almost nothing except eat, sleep, play disc golf, and think about disc golf.
The lack of love the golfer offers to the non-golfer, while offering what appears to be all their love to a sport, is what does the damage. For the purposes of this article, I am going be sexist, and assume that the golfer is a male, and the non-golfer is a female. But of course, what follows applies to all loving relationships between disc golfers and non-disc-golfers.
Men tend to get a bit lazy over time and fail to properly demonstrate their love for their partners. Often this failure coincides with golfing activities, which is another nail in the disc golf relationship coffin. Women need to know they are number one.
How the compact disc lost its shine
Because of course, they are! Your partner IS more important than disc golf This is the basic assumption of this article. You would rather give up a round of disc golf, or a tournament, for your partner, than vice versa. Once you understand and mentally accept this basic fact, everything else follows from it. It is also very important to explain that their love of disc golf is the lesser of their two great loves. Happy wife — Good life. Sad wife — Bad Life.
Oh, how I wish I could communicate this to all men — not just disc golfers. In a relationship, your own happiness stems from the happiness of your partner. If your partner is deliriously happy, it is almost impossible for your relationship to fail. A good relationship brings happiness from outside, as well as inside the relationship.
Any time the happiness comes from only one side, problems will arise. What do I mean by this? It means that each person in a relationship needs to be made happy by their partner, but they also need external things which make them happy.
If this write succeeds, the original allocation unit is marked as unusable. If the write fails, the disk is taken offline. One unique benefit on ASM-based mirroring is that the database instance is aware of the mirroring.
For many types of logical corruptions such as a bad checksum or incorrect System Change Number SCNthe database instance proceeds through the mirror side looking for valid content and proceeds without errors.
If the process in the database that encountered the read is in a position to obtain the appropriate locks to ensure data consistency, it writes the correct data to all mirror sides. When encountering a write error, a database instance sends the ASM instance a disk offline message.
If database can successfully complete a write to at least one extent copy and receive acknowledgment of the offline disk from ASM, the write is considered successful. If the write to all mirror side fails, database takes the appropriate actions in response to a write error such as taking the tablespace offline. When the ASM instance receives a write error message from an database instance or when an ASM instance encounters a write error itself, ASM instance attempts to take the disk offline.
If too many partners are already offline, ASM forces the dismounting of the disk group. Otherwise, ASM takes the disk offline.
For information on the remap command, see "remap Command". This is especially true if the recovery process requires rebuilding an entire ASM failure group. ASM fast mirror resync significantly reduces the time to resynchronize a failed disk in such situations. To use this feature, the disk group compatibility attributes must be set to For more information, refer to "Disk Group Compatibility". Any problems that make a failure group temporarily unavailable are considered transient failures that can be recovered by the ASM fast mirror resync feature.
For example, transient failures can be caused by disk path malfunctions, such as cable failures, host bus adapter failures, controller failures, or disk power supply interruptions.
The extents are resynced when the disk is brought back online. By default, ASM drops a disk in 3. The time can be specified in units of minutes m or M or hours h or H.
If you omit the unit, then the default unit is hours. If the attribute is not set explicitly, then the default value 3. However, make sure that the attribute value is set to the amount of time that you think is necessary in your environment to fix any transient disk error and that you are willing to tolerate reduced data redundancy.