similar to: File fragmentation

I've been running some tests on files created by rsync and noticing fragmentation issues. I started the testing because our 5TB array started performing very slowly and it appears fragmentation was the culprit. The test I conducted was straighforward: 1. Copy over a 49GB file. Analyzed with contig (from sysinternals), no fragments. 2. Ran rsync and the file was recreated normally (rsync

When I use the preallocate patch and create a 77GB file using the function I get a CPU spike on the server-side. The spike lasts about 20 minutes and uses about 20%-25% of the cpu associated with the rsync instance creating the file. The spike is directly linked to the time it takes to create the file. I compiled rsync using cygwin CVS. I initially suspected the implementation of

Greetings, I would like to write a patch for rsync but need some help getting started. Here is my situation. I am using cwrsync to copy files from one Windows server to another Windows server. One file that I need to backup is 130 GB. The daily changes occur all throughout the file, not just at the end of the file. File names look like this: Db_20080402_0003_DB.BAK Db_20080403_0003_DB.BAK

Hi Timo, Any chance the mbox/mdbox writer code could be modified to do physical preallocation on files to help avoid file(system) fragmentation? Constantly appending a file is the prime recipe for causing fragmentation, and mbox is notorious for this--not a fault of Dovecot but the nature of the mbox beast. Obviously maildir doesn't have such a problem, but some (many?) of us still prefer

Hi All I was reading through this: http://kashyapc.com/2011/12/02/little-more-disk-io-perf-improvement-with-fallocateing-a-qcow2-disk/ I was basically searching for pointers on improving disk I/O. I wanted to know the purpose of preallocation=full & preallocation=metadata , What is the difference between them ? and which one would yield a better disk I/O speed ? Appreciate your

On Thu, Mar 29, 2018 at 1:59 PM Richard W.M. Jones <rjones@redhat.com> wrote: > I found another problem which is sort of related to this thread. I > hit a time-out waiting for the disk to be unlocked after creation: > > > https://github.com/libguestfs/libguestfs/commit/8081f54105bd990233f166170890192c1fd7d1f3#diff-5ca47c29ae13efa3959b8b28cf4dbd31R112 > line 112 > >

Recently I ran into a situation where an ocfs2 (1.4) volume was reporting it was out of space when it was not. Deleting some files helped short term but the problem quickly comes back. I believe this is due to the fragmentation bug that I have seen references to in the mailing list archive. I am trying to reproduce the problem on a test system so that I can validate that upgrading to 1.6

Improving Samba write performance on Linux ------------------------------------------ Abstract -------- Samba performance is good in most circumstances, but modern Linux distributions have improved file systems since Samba was first developed. In particular, they have a feature that Samba does not take advantage of by default. In recent work I found that making some simple changes to Samba could

A lot of code runs 'qemu-img create' or 'truncate' to create blank disk images. In the past I resisted adding an API to do this, since it essentially duplicates what you can already do using other tools (ie. qemu-img). However this does simplify calling code quite a lot since qemu-img is somewhat error-prone to use (eg: don't try to create a disk called "foo:bar")

Let me preface this by saying "Yes, I know *nix filesystems don't need to worry about fragmentation". That said, is there a way to check the overall level of fragmentation of a live ext3 filesystem? I know about filefrag, but that's for specific files. And I think e2fsck tells you, but only if you take the filesystem offline for the scan. Is there anything that will give

I have a huge problem with ZFS pool fragmentation. I started investigating problem about 2 weeks ago http://www.opensolaris.org/jive/thread.jspa?threadID=34423&tstart=0 I found workaround for now - changing recordsize - but I want better solution. The best solution would be a defragmentator tool, but I can see that it is not easy. When ZFS pool is fragmented then: 1. spa_sync function is

We have been using ext3 for our Maildir message store for the better part of a year now. I saw Stephen mention fragmentation and wondered if we might be affected from this as well. How can I find out how fragmented our message store is? -- Ralf Hildebrandt (Im Auftrag des Referat V A) Ralf.Hildebrandt@charite.de Charite Campus Virchow-Klinikum Tel. +49 (0)30-450 570-155

Hello, I''ve hit known problem with dynamic memory management - memory fragmentation... This dynamic memory management basically does xl mem-set to balance memory. After some time of running system, xen memory is so fragmented that it is impossible to start new VM with PCI device. Sometimes it crashes during boot (no 64MB contiguous memory for SWIOTLB), or later - eg. iwlagn cannot

Does FreeBSD have fallocate(2) or equivalent? On Mon, Oct 30, 2017 at 4:32 PM, Ed Maste <emaste at freebsd.org> wrote: > On 23 October 2017 at 18:49, Rui Ueyama via llvm-dev > <llvm-dev at lists.llvm.org> wrote: > >> > >> BTW, posix_fallocate() might provide better portability and decrease the > >> likelihood of falling back on ftruncate(). > >

I have been running a lot of large compression tests to see how well Martijn van Beurden's new presets do and was once again reminded how real the fragmentation problem still is. To have decent speed it's necessary to run multiple encoders in parallel. In my setup FLAC was compressing four files at the same time and each instance writes tiny bits of data to disk at once. A

Hi, As I found out yesterday, the fragmentation of the "Enterprise Linux" ecosystem just started to come true. I expect this is only the beginning and Red Hat may also start to completely hold back sources of non GPL software which is part of the "Enterprise Linux" ecosystem. I'm really wondering, how will this help anybody and how will this help Red Hat in the long run?

Hello Marc, I'm referring to divide/fragment de Database AD (if possible). Trying to store a set of Data in a DC and another set of data in other DC... something like this. I ask that, because I've been asked for a strategy or mechanism related to the scalability which based on the horizontal fragmentation of AD. Then, Does AD have some type of mechanism for supporting the horizontal

Please reference the prior RFC on EfficiencySanitizer. This is one of the performance analysis tools we would like to build under the EfficiencySanitizer umbrella. ==================== Motivation ==================== An application is running sub-optimally if only part of the data brought into the cache is used, which we call cache fragmentation. Knowing the cache fragmentation information

I've read in Phil Spector's new book that it's a good idea to preallocate a big matrix, like u <- matrix(0,nrow,ncol) # (1) Now, I read contents of a huge matrix from a Fortran binary dump. u <- readBin(con,what="double",n=nrow*ncol) # (2) If I do (1) and then (2), u is a vector, obviously it's either reallocated or its matrix nature is lost -- overridden?

On 09.04.2016 21:40, Marcelo Ricardo Leitner wrote: > Hi, > > Em 07-04-2016 12:19, Volker escreveu: >> Hi all. >> >> I have a strange problem at hand regarding UDP fragmentation on Centos7: >> Applications are unable to receive UDP packets which have undergone >> fragmentation UNLESS the netfilter modules are loaded. >> >> The problem arose on a