I've heard from somewhere that if server is using swapping constantly then eventually you have to buy new hard drives because they get killed off like that.
So I have,
Total processors: 8 (2xQuad core Intel(R) Xeon(R) CPU E5405 @ 2.00GHz)
RAM: 32GB (16x2GB)
Interface is running bond mode 6.
Plenty of hard drives to cover 12TB of Disk Space in Raid 0 (4x4TB)
I have found few threads about swapping and read them through.
http://forums.cpanel.net/f34/memory-usage-apparently-higher-than-expected-308861.html#post1277421
performance - Why use swap when there is more than enough RAM - Unix & Linux Stack Exchange
Linux: Should You Use Twice the Amount of Ram as Swap Space?
http://www.chrisjohnston.org/ubuntu/why-on-linux-am-i-seeing-so-much-ram-usage
However in my case when RAM usage reaches up to 20-25% it starts to use swap. But seriously isn't it more healthyer for server to use purely RAM without swapping? Also there is no way whatsoever to clear swap using without restarting the server. RAM usage seems to be more safe.
I have Linux system and if I would switch default that is about 3/4 of system ram in use or more equals swap usage - Into some less swap usage like 0.5 instead of 0.6 meybe? I've heard it's not good to zerofy swap usage out either because then RAM usage goes twice as high immediately.
#cat /proc/swaps
#swapon -s
# free -m
# top
# cat /proc/meminfo
Where, in which files in Linux can swap limits be changed?
# locate swap
So I have,
Total processors: 8 (2xQuad core Intel(R) Xeon(R) CPU E5405 @ 2.00GHz)
RAM: 32GB (16x2GB)
Interface is running bond mode 6.
Plenty of hard drives to cover 12TB of Disk Space in Raid 0 (4x4TB)
I have found few threads about swapping and read them through.
http://forums.cpanel.net/f34/memory-usage-apparently-higher-than-expected-308861.html#post1277421
performance - Why use swap when there is more than enough RAM - Unix & Linux Stack Exchange
Linux: Should You Use Twice the Amount of Ram as Swap Space?
http://www.chrisjohnston.org/ubuntu/why-on-linux-am-i-seeing-so-much-ram-usage
However in my case when RAM usage reaches up to 20-25% it starts to use swap. But seriously isn't it more healthyer for server to use purely RAM without swapping? Also there is no way whatsoever to clear swap using without restarting the server. RAM usage seems to be more safe.
I have Linux system and if I would switch default that is about 3/4 of system ram in use or more equals swap usage - Into some less swap usage like 0.5 instead of 0.6 meybe? I've heard it's not good to zerofy swap usage out either because then RAM usage goes twice as high immediately.
#cat /proc/swaps
Code:
Filename Type Size Used Priority
/dev/dm-1 partition 4063224 0 -1
Code:
Filename Type Size Used Priority
/dev/dm-1 partition 4063224 0 -1
Code:
total used free shared buffers cached
Mem: 32112 11029 21082 0 411 4093
-/+ buffers/cache: 6525 25587
Swap: 3967 0 3967
Code:
top - 01:24:17 up 4 days, 7:00, 1 user, load average: 0.22, 0.15, 0.15
Tasks: 364 total, 1 running, 361 sleeping, 0 stopped, 2 zombie
Cpu0 : 1.0%us, 0.5%sy, 0.0%ni, 98.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu1 : 1.0%us, 1.0%sy, 0.0%ni, 98.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu2 : 3.4%us, 1.5%sy, 0.0%ni, 95.1%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu3 : 2.0%us, 1.0%sy, 0.0%ni, 97.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu4 : 0.5%us, 0.5%sy, 0.0%ni, 99.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu5 : 1.0%us, 0.5%sy, 0.0%ni, 98.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu6 : 0.5%us, 0.5%sy, 0.0%ni, 99.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu7 : 3.9%us, 1.5%sy, 0.0%ni, 94.6%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 32883272k total, 11302132k used, 21581140k free, 421148k buffers
Swap: 4063224k total, 0k used, 4063224k free, 4191768k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
4 root 20 0 0 0 0 S 11.9 0.0 533:48.61 [ksoftirqd/0]
9 root 20 0 0 0 0 S 4.9 0.0 310:44.05 [ksoftirqd/1]
13 root 20 0 0 0 0 S 4.5 0.0 163:19.83 [ksoftirqd/2]
29 root 20 0 0 0 0 S 2.5 0.0 63:10.00 [ksoftirqd/6]
33 root 20 0 0 0 0 S 2.0 0.0 60:08.67 [ksoftirqd/7]
6075 nobody 20 0 163m 57m 3256 S 2.0 0.2 0:10.61 /usr/local/apache/bin/httpd -k
5140 nobody 20 0 163m 58m 3452 S 1.5 0.2 0:12.20 /usr/local/apache/bin/httpd -k
17214 root 20 0 15308 1468 948 R 1.0 0.0 0:00.05 top
1407 root 20 0 150m 15m 1460 S 0.5 0.0 0:04.39 lfd - sleeping
1726 root 20 0 0 0 0 S 0.5 0.0 0:51.57 [bond0]
16908 mailnull 20 0 301m 79m 4316 S 0.5 0.2 0:02.31 MailScanner: waiting for messa
Code:
MemTotal: 32883272 kB
MemFree: 21590552 kB
Buffers: 421168 kB
Cached: 4192168 kB
SwapCached: 0 kB
Active: 9768000 kB
Inactive: 621904 kB
Active(anon): 5776872 kB
Inactive(anon): 32 kB
Active(file): 3991128 kB
Inactive(file): 621872 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 4063224 kB
SwapFree: 4063224 kB
Dirty: 680 kB
Writeback: 0 kB
AnonPages: 5776576 kB
Mapped: 30984 kB
Shmem: 372 kB
Slab: 494144 kB
SReclaimable: 390960 kB
SUnreclaim: 103184 kB
KernelStack: 3376 kB
PageTables: 54896 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 20504860 kB
Committed_AS: 8807312 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 104408 kB
VmallocChunk: 34359591104 kB
HardwareCorrupted: 0 kB
AnonHugePages: 3201024 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 7488 kB
DirectMap2M: 33546240 kB
# locate swap
Code:
/home/.cpanm/work/1373665143.30705/BSD-Resource-1.2906/blib/lib/auto/BSD/Resource/nswap.al
/home/.cpanm/work/1373810466.27407/BSD-Resource-1.2907/blib/lib/auto/BSD/Resource/nswap.al
/home/virtfs/cf/sbin/mkswap
/home/virtfs/cf/sbin/swapoff
/home/virtfs/cf/sbin/swapon
/sbin/mkswap
/sbin/swapoff
/sbin/swapon
/usr/include/byteswap.h
/usr/include/bits/byteswap.h
/usr/include/sys/swap.h
/usr/lib/anaconda/iw/upgrade_swap_gui.py
/usr/lib/anaconda/iw/upgrade_swap_gui.pyc
/usr/lib/anaconda/iw/upgrade_swap_gui.pyo
/usr/lib/anaconda/storage/devicelibs/swap.py
/usr/lib/anaconda/storage/devicelibs/swap.pyc
/usr/lib/anaconda/storage/devicelibs/swap.pyo
/usr/lib/anaconda/storage/formats/swap.py
/usr/lib/anaconda/storage/formats/swap.pyc
/usr/lib/anaconda/storage/formats/swap.pyo
/usr/lib64/perl5/bits/byteswap.ph
/usr/lib64/pm-utils/bin/pm-reset-swap
/usr/local/cpanel/3rdparty/perl/514/lib64/perl5/cpanel_lib/x86_64-linux-64int/auto/BSD/Resource/nswap.al
/usr/local/cpanel/bin/swapip
/usr/local/cpanel/perl/BSD/Resource/nswap.al
/usr/local/lib64/perl5/auto/BSD/Resource/nswap.al
/usr/share/doc/db4-devel-4.7.25/api_c/db_get_byteswapped.html
/usr/share/doc/db4-devel-4.7.25/api_cxx/db_get_byteswapped.html
/usr/share/doc/db4-devel-4.7.25/api_tcl/db_is_byteswapped.html
/usr/share/doc/db4-devel-4.7.25/ref/upgrade.3.3/getswap.html
/usr/share/man/man2/swapcontext.2.gz
/usr/share/man/man2/swapoff.2.gz
/usr/share/man/man2/swapon.2.gz
/usr/share/man/man3/BN_swap.3ssl.gz
/usr/share/man/man3/swapcontext.3.gz
/usr/share/man/man3p/swapcontext.3p.gz
/usr/share/man/man8/mkswap.8.gz
/usr/share/man/man8/swapoff.8.gz
/usr/share/man/man8/swapon.8.gz
/usr/share/vim/vim72/macros/swapmous.vim
Last edited: