- Community Home
- >
- Servers and Operating Systems
- >
- Operating Systems
- >
- Operating System - Linux
- >
- Re: Free Memory always low - What Happened to My M...
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 06:04 AM
тАО11-19-2009 06:04 AM
Free Memory always low - What Happened to My Memory?
I am clueless what's causing this and am about to just re-image and track my steps and see when this issue start to manifest itself.
# free
total used free shared buffers cached
Mem: 132101528 131514200 587328 0 4552 9224
-/+ buffers/cache: 131500424 601104
Swap: 67076088 66732 67009356
]# cat /proc/meminfo
MemTotal: 132101528 kB
MemFree: 585984 kB
Buffers: 4916 kB
Cached: 9888 kB
SwapCached: 9924 kB
Active: 18452 kB
Inactive: 6772 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 132101528 kB
LowFree: 585984 kB
SwapTotal: 67076088 kB
SwapFree: 67009360 kB
Dirty: 8 kB
Writeback: 0 kB
AnonPages: 8684 kB
Mapped: 5932 kB
Slab: 42140 kB
PageTables: 3948 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
CommitLimit: 67443396 kB
Committed_AS: 179648 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 302444 kB
VmallocChunk: 34359435055 kB
HugePages_Total: 64144
HugePages_Free: 64144
HugePages_Rsvd: 0
Hugepagesize: 2048 kB
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 06:13 AM
тАО11-19-2009 06:13 AM
Re: Free Memory always low - What Happened to My Memory?
-/+ buffers/cache: 131500424 601104
There it is.
When memory is in use Linux puts it in buffer cache to speed up I/O. Unlike older versions of HP-UX it can pull memory from cache very quickly.
SEP
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 06:19 AM
тАО11-19-2009 06:19 AM
Re: Free Memory always low - What Happened to My Memory?
But is this the normal behaviour? I've other servers - freshly installed, similarly patched that I've not:
presented SAN LUNs yet
installed our custom scripts
mod'd sysctl.conf, limits.conf for Oracle
And I do not see any issue.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 06:23 AM
тАО11-19-2009 06:23 AM
Re: Free Memory always low - What Happened to My Memory?
I'm dealing with VERY large Linux machines btw.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 08:36 AM
тАО11-19-2009 08:36 AM
Re: Free Memory always low - What Happened to My Memory?
Write a program to do some malloc, large chunk of memory, say 256 MB.
Your request will get what it needs instantly. The system will not page and the buffer figures will decline.
SEP
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 09:11 AM
тАО11-19-2009 09:11 AM
Re: Free Memory always low - What Happened to My Memory?
I am now backtracking and I think I found the culprit. I've the latest HP Multipathing package and Redhat's latest multip-pathing package.
When I tried to collpase my LVM VG that sits on a multi-pathed EVA LUN, the OS ran out of Memory and eventually Panic'd.
SO I am rolling back to HPDMmultipath-4.2.0 instead of 4.3 first and then rollback :
device-mapper.i386 1.02.32-1.el5 installed
device-mapper.x86_64 1.02.32-1.el5 installed
device-mapper-event.x86_64 1.02.32-1.el5 installed
device-mapper-multipath.x86_64 0.4.7-30.el5_4.2 installed
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 09:56 AM
тАО11-19-2009 09:56 AM
Re: Free Memory always low - What Happened to My Memory?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 09:59 AM
тАО11-19-2009 09:59 AM
Re: Free Memory always low - What Happened to My Memory?
On other servers where I do not have any persented SAN disks and no VGs and Lvols and Filesystems carved -- my memory is fine.
Now how do I roll-back my device-mapper packages? just "yum downgrade" ?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 12:49 PM
тАО11-19-2009 12:49 PM
Re: Free Memory always low - What Happened to My Memory?
yum remove package_name
Do take a look at the list in case there are unexpected dependencies.
SEP
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО11-19-2009 01:02 PM
тАО11-19-2009 01:02 PM
Re: Free Memory always low - What Happened to My Memory?
But I lost lvm tools.
I have a breakthough though on what's causing my issues.
My Kernel Configuration that was passed on to me by a DBA:
vm.nr_hugepages = 70000
vm.zone_reclaim_mode = 1
kernel.shmmni = 4096
kernel.shmmax = 0x4000000000
kernel.sem = 250 32000 250 128
net.ipv4.ip_local_port_range = 1024 65000
fs.aio-max-nr=804800
net.core.rmem_default = 262144
net.core.wmem_max = 262144
net.core.wmem_default = 262144
net.core.rmem_max = 262144
fs.file-max = 6553600
When I remove vm.nr_hugepages = 70000, my mem woes are gone.
Anyone knows what should be the proper value? The DB will most likely have ~32GB max SGA size and I think that's what it is used for --for Oracle to use huge pages.