Too Much Swapping, even though RAM is 2/3 Empty

Posted by indyaah on Super User See other posts from Super User or by indyaah
Published on 2012-11-20T23:04:04Z Indexed on 2012/11/20 23:05 UTC
Read the original article Hit count: 119

Filed under:

hard-drive

|

memory

|

centos

|

swap

|

postgresql

I have a VPS with 9GB RAM, 300GB HDD, 3 GB Swap, 7 Cores. The OS is CentOS 5.7 Final.

I have postgres9.0 running on my machine, with proper tuning done (at least by book/wiki of PostgreSQL).

What happens is most of the times when some complex query run (by complex I mean select with maximum 3 Joins), eventhough 66% of my RAM is unused there is ~99% swapping is happening.

Plus it screws up my disk IO which is most of the time reaching ~100% and slows down everything else. (I tend to believe something's wrong with my disk.)

I dont understand the reason of this much of swapping happening. Is it because of context switching?? Most of the time my processors are idle, while the IO wait goes upto 30% during pick times.

Would appreciate if some can shed some light on it.

Thanks.

© Super User or respective owner

Related posts about hard-drive

Move smaller hard drive to partition on a larger hard drive

as seen on Super User - Search for 'Super User'
My parents bought a new hard drive for a laptop that I've owned for several years. It's much larger than the current one, so I plan on splitting it up to dual boot it with Ubuntu. I have no problem with partitioning a drive (I always keep a LiveCD handy), but my question is this: how can I go about… >>> More
Using an ATA-100 Hard Drive with a Thermaltake BlacX External Hard Drive Dock

as seen on Super User - Search for 'Super User'
Is it possible for a Thermaltake BlacX HDD Dock to connect to and recognize an ATA-100 Hard Drive? I know that the specifications for the BlacX say that it only supports SATA & SATAII, but I was hoping for one of three things: 1) for it to still work even though it isn't supported 2) for there… >>> More
Copy the contents of one hard drive partition to anohter hard drive partition

as seen on Super User - Search for 'Super User'
I have made a C++ program which can copy the whole hardrive partition to another hardrive partition, but now I am looking forward for the program which can only copy the contents of one hardrive partiton to another hardrive partition. >>> More
backup hard drive image on external hard drive for Windows 7

as seen on Super User - Search for 'Super User'
Hello, I am looking for a backup tool for Windows 7, that will allow me to backup my laptop’s hard drive on an external hard drive as an exact image. In a case of a problem with the main hard drive, I would like just to swap the drives and to continue to work using the backup hard drive. Thanks >>> More
Copy the contents of one hard drive partition to anohter hard drive partition

as seen on Stack Overflow - Search for 'Stack Overflow'
I have made a C++ program which can copy the whole hardrive partition to another hardrive partition, but now I am looking forward for the program which can only copy the contents of one hardrive partiton to another hardrive partition. >>> More

Related posts about memory

SQL Server and Hyper-V Dynamic Memory Part 2

as seen on SQL Blog - Search for 'SQL Blog'
Part 1 of this series was an introduction and overview of Hyper-V Dynamic Memory. This part looks at SQL Server memory management and how the SQL engine responds to changing OS memory conditions. Part 2: SQL Server Memory Management As with any Windows process, sqlserver.exe has a virtual… >>> More
SQL Server and Hyper-V Dynamic Memory - Part 1

as seen on SQL Blog - Search for 'SQL Blog'
SQL and Dynamic Memory Blog Post Series Hyper-V Dynamic Memory is a new feature in Windows Server 2008 R2 SP1 that allows the memory assigned to guest virtual machines to vary according to demand. Using this feature with SQL Server is supported, but how well does it work in… >>> More
SQL Server and Hyper-V Dynamic Memory - Part 1

as seen on SQL Blog - Search for 'SQL Blog'
SQL and Dynamic Memory Blog Post Series Hyper-V Dynamic Memory is a new feature in Windows Server 2008 R2 SP1 that allows the memory assigned to guest virtual machines to vary according to demand. Using this feature with SQL Server is supported, but how well does it work in… >>> More
Python Memory leak - Solved, but still puzzled

as seen on Stack Overflow - Search for 'Stack Overflow'
Dear everyone, I have successfully debugged my own memory leak problems. However, I have noticed some very strange occurence. for fid, fv in freqDic.iteritems(): outf.write(fid+"\t") #ID for i, term in enumerate(domain): #Vector tfidf = self.tf(term… >>> More
SQL Server and Hyper-V Dynamic Memory Part 3

as seen on SQL Blog - Search for 'SQL Blog'
In parts 1 and 2 of this series we looked at the basics of Hyper-V Dynamic Memory and SQL Server memory management. In this part Serdar looks at configuration guidelines for SQL Server memory management. Part 3: Configuration Guidelines for Hyper-V Dynamic Memory and SQL Server Now that… >>> More