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Questions tagged [fragmentation]

File system fragmentation is the inability of a file system to lay out related data sequentially (contiguously), an inherent phenomenon in storage-backed file systems that allow in-place modification of their contents.

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ZFS disk with Postgresql fragmenting quickly with write-heavy application

I am running a write-heavy application where I am storing my Postgresql on ZFS. Generally, it works well, but I am finding that my ZFS pool is fragmenting heavily. I even created a new ZFS pool and ...
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how to set mtu on specfic udp connection?

is there iptables target to fragment packets, let say i have packet with length 1280 i want to split this packet into smaller 5 packets with maximum length equal 250 , is it possible to use firewall ...
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1 vote
1 answer
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How to fix ws and socket.io memory leak?

I have read that there is a memory leak occurring in both node.js websocket modules ws and socket.io. It has existed for years and am wondering how to fix it. It is mentioned in the following, to name ...
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3 votes
1 answer
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SSH connection problems through OpenVPN tunnel (“TCP Previous segment lost”)

I have a VPN tunnel to an OpenVPN server. The VPN is a Sophos VPN which uses OpenVPN under the hood. I do not know the server configuration nor can I change the server config. My tunnel endpoint is ...
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6 votes
1 answer
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How does Windows Storage Space deal with partition fragmentation? Will this cause performance issues?

I'm using Windows Storage Space with multiple hard drives. If I create multiple virtual disks, then delete some of them, and resize some of them, will the virtual disk be finally divided into ...
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1 vote
1 answer
927 views

How to block incoming IPv6 fragments?

I have an issue with my firewall configuration. I would like to block all IPv6 fragmented packets in a sopecific interface. So, I tried: # ip6tables -A INPUT -d <ipv6_address> -i eth0 -m ...
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2 votes
1 answer
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xfs_db reports high file fragmentation where VM is located, but VM shows almost no fragmentation

I have several libvirt VMs stored on xfs partitions and am using gluster to replicate the storage. The VMs use qcow2 for storage. Some of the partitions where the VMs are located indicate high file ...
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1 vote
1 answer
498 views

xfs_fsr reports insufficient freespace on large VM images

I have several systems using glusterfs and xfs partitions. Some of these systems are hosts for VMs (using libvirt and with qcow2 for storage). I noticed that there was some substantial fragmentation ...
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1 vote
1 answer
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Is Windows able to run Disk Optimize with SQL Server running?

I've just inherried a SQL Server, where the database file growth was set to 1MB. So there are a lot of databases (>25) that have grown in small increments until now (currently totalling 300 GB). So I ...
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3 votes
1 answer
186 views

fragmentation leads to excessive vhdx backup size

The server hosts a service called MultiCash-Datenbank. For each user it keeps two cache files (SPASD32.SRC and SPASD32Z.SRC), which grow in size by ~1MB/day. There's also a bunch of small data files ...
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2 answers
798 views

Packet fragmentation confusion

I was playing around with dpkt in Python, trying to decode PPPoE - and the program was working just fine, till I noticed that the Offset in the encapsulation IP packets was always 0, even with clearly ...
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9 votes
2 answers
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How to handle Redis raising memory fragmentation?

I have a Redis 3.0.5 instance that tend to show growing mem_fragmentation_ratio over time. The application using that instance is constantly creating and deleting keys. After one month, I end up ...
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10 votes
5 answers
47k views

How to use MSSQL, rebuild all indexes on all tables? MSSQL Server 2008

I have a mssql database, we'll call it: mssqlDB01. I've been tasked with performing defragmentation on all of the tables. This database has a few hundred tables and each table has a range of 1 to 15 ...
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1 vote
1 answer
4k views

Refs: is fragmentation ok / is defragmentation needed?

I run ReFS in two configurations: In a storage spaces mirror (2x4TB), for most valuable data Standalone on a single disk, for offsite backups (NB: not my only backup) In both of these configurations ...
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1 vote
1 answer
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verisign error -> Query to DNSKEY timed out or failed

I am trying to find the origin of an error I cannot get rid of on the verisign dnssec debugger Verisign debugger Dig queries the server just fine dig ex-mailer.com ANY @108.61.190.64 All of my ...
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1 vote
1 answer
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Will 2 heavy, simultaneous IO operations result in fragmentation?

I'm using Ubuntu 14.04 to run a web/DB server. Disks are in a RAID6 set, using XFS. I'm somewhat new to XFS. Suppose I have 2 heavy IO operations. In my example: Reindexing a 400 GB database. ...
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4 votes
2 answers
342 views

ADSL router happily accepts IPv6 packets of 2K in size

As I understand IPv6 fragmentation, the routers do not perform fragmentation, only the end-to-end nodes do. And when any router along the path receives a packet larger than the MTU of the link to its ...
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18 votes
2 answers
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Cause of page fragmentation on "large" server with xfs, 20 disks and Ceph

Any insight from someone with a bit of experience in the linux IO system would be helpful. Here is my story: Recently brought up a cluster of six Dell PowerEdge rx720xds to serve files via Ceph. ...
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-1 votes
1 answer
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windows update error 80072ee2 caused by linux router, possible mtu issue? [closed]

For a few days now, the Windows 7 workstations on my network have been unable to connect to Windows Update. They are getting the infamous error 80072ee2. They are connected to a simple SOHO switch. ...
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Windows Server 2012 R2 : Drive C: gets fragmented very quickly

We are running Windows Server 2012 R2 with the Hyper-V role installed. I have discovered that the host's volume C: get's fragmented very quickly (about 4% in only 1h). Our SCOM configuration ...
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2 answers
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Fragmentation and packet size,using tcpdump

i am trying to understand concept of fragmentation: i have two virtual machines with public ip connected to a switch. tracepath shows packet not going through gateway from vm1: Trying to send ...
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0 votes
1 answer
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How to prevent file fragmenting when you are creating archive

i have a test environment with subversion, im making DUMP files (20GB) and then compressing it. It gives me 12GB file, but with over 500 fragments. Question is, is there a way to archive file into one ...
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4 answers
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Fragmentation of packets in networks [closed]

Why may packets sent over the internet be fragmented? I don't understand why data grams are broken up into smaller pieces. When this is done what is its use?
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1 vote
1 answer
2k views

Rebuilt nonclustered indexes quickly get fragmented again

I've got a couple of nonclustered indexes on tables that have rows inserted quite often. These indexes are currently around 90% fragmented, according to SQL Server. If I rebuild them, they go down to ~...
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0 answers
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Can someone give me advice on these rules to prevent DDOS where fragmented packets are sent without the initial SYN fragment ?

iptables -N NEW_TCP_PACKETS_NO_SYN iptables -A INPUT NEW_TCP_PACKETS_NO_SYN -p tcp ! --syn -m state --state NEW -m limit --limit 10/day -j LOG --log-prefix "New packets but not syn:" iptables ...
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2 answers
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Mysql 5.5 Defragmentation not reducing the fragmentation percent

We are running OPTIMIZE TABLE , but not seeing any fragmentation reduction. They are as high as 120% to 200%. Am calculating the fragmentation % using this: Data_Free / (Data_Length + Index_Length) ...
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1 vote
2 answers
748 views

Scientific data storage: many small files, one volume or several?

I have about 8 TB worth of 'sample' data with the following characteristics: each sample: 5-15 GB in one folder containing ~20k files and ~10k subfolders (2000 top-level, 5 sub-level containing a ~.5-...
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1 vote
3 answers
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Rebuilding the Management Studio Index in SQL Server 2005

Does anyone know if using the SQL Server Management Studio Index Rebuild, rebuilds the index online or offline? Reading the help documentation doesn't say anything on this (so I would assume it is ...
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0 votes
1 answer
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Fragmented packets on Red Hat Linux

Our application runs on Red Hat Linux 8.0 3.2-7, Linux kernel version 2.4.32. We've found that the OS does not know how to handle fragmented packets. When receiving a large amount of fragmented ...
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4 votes
1 answer
6k views

Is there a way of setting an MTU lower for traffic destined to a specific IP address on Cisco ASA?

I have a number of VPN sites where the MTU is lower than standard (1500). I have had at least one site where fragmentation of packets has had an effect on the success of building an IPSEC tunnel. ...
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1 vote
1 answer
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(RFC-791) Application Layer PDU size, guaranteed to pass without fragmentation

I am writing a client-server python application, a part of which is using UDP Multicast to communicate. And my current concern is about fragmentation. RFC 791 (page 24) says: Every internet module ...
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6 votes
2 answers
798 views

Can a tmpfs become fragmented?

Since a tmpfs exists only in memory, can it become fragmented like memory can? Are there mechanisms to automatically defragment the memory, and thus increase - even slightly - the access speed of ...
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4 votes
3 answers
11k views

What might prevent IKE handshake success in building an IPSEC tunnel?

We use Cisco ASA for our IPSEC VPNs, using the EZVPN method. From time to time we encounter problems where an ISP has made a change to their network and our VPN stops working. Nine times out of ten ...
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2 votes
4 answers
625 views

How accurate are Diskeeper's claims that fragmentation causes crashes, aborted bootups and other mayhem?

A white paper published by Diskeeper Corporation states at page 3 that, The most common problems caused by file fragmentation are: a) Crashes and system hangs/freezes b) Slow boot up and ...
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0 votes
1 answer
521 views

how to do fragmentation attack via ubuntu machine

I wish to test my system which has snort installed on it. I want to do fragmentation attack such as tiny fragment attack and wish that it should be logged by snort. any suggestions? any graphical ...
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1 vote
1 answer
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Index fragmentation and reorganizing database pages

Say you have a database with heavy index fragmentation. Say this database also has a lot of free space due to frequent deletes in its data file. This free space is not contiguous. If I rebuild all ...
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0 votes
2 answers
483 views

How can Windows defragmentation tools cause internal fragmentation in SQL Server?

I was just reading this article where the author talks about the file system fragmentation that can be caused by growing database files. There was one bit that I didn't quite follow. What about ...
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3 votes
1 answer
293 views

IPv4 Fragmentation over ethernet

I was under the assumption that fragmentation only happens at the router however this makes me wonder how datagrams get to the router without first being fragmented at the source to comply with the ...
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23 votes
4 answers
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Linux memory fragmentation

Is there a way to detect memory fragmentation on Linux? This is because on some long running servers I have noticed performance degradation and only after I restart process I see better performance. I ...
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1 vote
3 answers
4k views

NETAPP Fragmentation

We all know that once a disk (or storage system for that matter) gets introduced into use, the performance degrades due to fragmentation of files. This seems to be why disk defragmentors are in ...
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6 votes
4 answers
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Does Windows Defrag utility reports fragmentation correctly on a RAID system?

We have a server with a RAID volume. Windows DEFRAG shows very high fragmentation (90%) on the volume. My chief asked if DEFRAG reported fragmentation is correct (or near correct) or not. We don't ...
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5 votes
2 answers
1k views

What is the equivalent of Cisco's 'ip virtual-reassembly' for a Juniper ISG 2000

I tested my dns servers with the oarc test and my size limit is at least 1403 bytes. I performed the same test before my Juniper ISG 2000 and the result is 2047 bytes. According to the chapter IP "...
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3 votes
3 answers
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Could MFT fragmentation be a problem on my busy file server?

Windows Server 2003 SP2 LUN mounted from SAN Millions of small files across hundreds of thousands of directories (100GB total) NTFS with 4k cluster size While doing the initial file crawl for backups ...
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1 vote
2 answers
1k views

Why can't I rebuild some SQL Server indices?

I've got a table in my SQL Server 2005 database with two indices that are heavily fragmented (33.3% and 85.7%). The table looks like the following: CREATE TABLE [dbo].[Seasons]( [SeasonID] [...
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1 vote
1 answer
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How is Win32_DefragAnalysis FilePercentFragmentation Calculated

SCOM 2007 R2 added a fragmentation analsysis health check that is producing warnings on many of my servers. To try to understand how SCOM is determines the fragmentation level, I created the following ...
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0 votes
1 answer
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Is there a way to determine fragmentation statistics about a single file on Win2003?

Basically, I don't care about fragmentation on the disk as a whole, I'm just curious about one file in particular... in my case, a SQL database and transaction log file. I'm looking for something ...
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3 votes
2 answers
3k views

How can I deliberately fragment specific files? (NTFS)

This may have been asked but... I'm trying to profile the impact of file fragmentation on one of our business applications. What's the easiest and cleanest way to cause a 20GB file to fragment into ...
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6 votes
8 answers
4k views

Swap file fragmentation: fact or fiction?

This is about Windows, but I'm sure it applies to other OS as well. I've heard people say that if you want better performance, you should avoid swap file fragmentation. To do this, you can either ...
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1 vote
1 answer
893 views

FTP Client upload: preallocate file before starting the transfer

I'd like to limit server disk fragmentation when multiple clients upload to an FTP server simultaneously. Is there a way to tell FTP server to preallocate disk space for a big block of an incoming ...
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19 votes
6 answers
12k views

SQL Database physical file fragmentation

I know that there are really three kinds of fragmentation that I need to be concerned about as a DBA: Index Fragmentation in the SQL data files, including clustered index (table) fragmentation. ...
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