Questions tagged [disk-cache]

Disk-cache: reserved area in RAM to speed-up disk access

A disk cache is a cache memory that is used to speed up the process of storing and accessing data from the host hard disk. It enables faster processing of reading/writing, commands and other input and output process between the hard disk, the memory and computing components.

The memory can be part of the disk drive itself (sometimes called a hard disk cache or buffer) or it can be general-purpose RAM in the computer that is reserved for use by the disk drive (sometimes called a soft disk cache). Hard disk cachesare more effective, but they are also much more expensive, and therefore smaller. Nearly all modern disk drives include a small amount of internal cache.

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MySQL slow, but speed up after drop disk caches

I have very busy Linux MySQL server with huge database. Server usually work on load average 2 or less. The server have software raid (mdadm) that is currently rebuilding. Several times today, MySQL get slower and load average reach 200-300-500. In…
Nick
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8x slower cat for the same files on the same disk but different directory

I'm having an issue where I have 8x slower access to a set of files as compared to the same files in another directory on a linux machine. The filesystem is a 36TB RAID-5 filesystem exported from a Dell PERC H810, and it's formatted with ext4. The…
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Can high disk cache usage lead to external fragmentation and ultimately to page allocation failures?

We're getting page allocation failures on a Linux server (3.2 kernel). We've been told the problem is directly related to the high use of the memory for cache; this would lead to external fragmentation, and ultimately to page allocation errors.…
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Linux not freeing the file buffer when we execute rm or > (redirection) operator

I have one router which has embedded-linux with kernel version 2.4.22 running on it. I know its very old version but i have to deal with it. Please take a look at the free command output when i run it on my box [8300002902-3] Debug> free …
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nginx proxy_cache or Memcached

I currently use nginx's proxy_cache for file-based caching in front of three Django applications (Apache/mod_wsgi). For some locations/URLs, I disabled proxy_cache and used Memcached (per view) within the Django app instead. Now I wonder whether…
janeden
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Which Linux filesystem is best for a huge Apache mod_disk_cache partition?

Talking about a huge (50GB, 500.000 entries) Apache disk_cache partition: Which Linux filesystem performs best for this task? In my example, the partition has a lot (500.000) of very small files (< 1 KB) and a lot (500.000) of files with ~ 50…
flight
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Linux server with JBoss , the system cache increased each day

We run an Apache Mod_proxy cluster with 3 JBoss in three dedicated server. Because we need share many files (small object files which our apps need to read/write ) between these JBoss servers ,we using NFS in Apache node and mount them into each…
hntangwei
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Raid Caching configuration suggestions

I'm wondering if there's the optimal Cache setting for the following Raid controllers and raid setups. (OS: windows 2008 R2, App: II7, DB: SQL Server 2008 R2 Enterprise) PERC 6/i: (The default setting seems to be: No Read Ahead/Write-back) 2 Disks…
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Google Cloud Function warning "OpenBLAS WARNING - could not determine the L2 cache size on this system"

I get the warning OpenBLAS WARNING - could not determine the L2 cache size on this system, assuming 256k in the logs of the "LOGS" tab of the Cloud Function. There is already a Q/A on this on Stack Overflow at AppEngine warning - OpenBLAS WARNING…
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