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 same time iostat is not big – 20-30% maximum. Swap is currently turned off, … Read more
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 total used free shared buffers Mem: 128104 123928 4176 … Read more
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. Here’s an excerpt of top’s output: top – 10:45:09 up 3 days, 17:10, 0 users, … Read more
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 machine has 256GB RAM, and I’m using OpenSuSE … Read more
When I try to disable disk cache on Windows Server 2012, I get “windows could not change the write-caching setting for the device” error. How do I disable the disk cache? Answer AttributionSource : Link , Question Author : real_sm , Answer Author : Community
I turned off write caching on an SATA drive using hdparm -W0 $DEV Now, sometimes, the kernel decides, it’s a good idea to hard reset an SATA link in order to get communication to a drive back up and running (maybe it is a good idea, won’t judge it here). However, if that happens, the … Read more
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 JBoss Node as same directory. Both nodes are installed RHEL 5.4 … Read more
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 KB. File hierarchy is as deep as /htcache/B/x/i_iGfmmHhxJRheg8NHcQ.header.vary/A/W/oGX3MAV3q0bWl30YmA_A.header. Typical actions are creating … Read more
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 pointing nginx to Memcached is more efficient. I read here, that nginx can serve pages from Memcached – but does Django … Read more
I have Varnish cache in front of some websites with the following storage engine configuration: Storage: file Size: 130GB The server where it is installed has the following configuration: RAM: 7.5 GB SSD 1: 15GB (System) SSD 2: 150GB (130GB for Varnish storage) CPU: 4 Summary, it is a c4.xlarge on AWS. Currently, Varnish is … Read more
