Note: this was tested and used on DSM5 and partly on 6. Since V7 I am not using this anymore.
Got and ssh into your box. Find what is using swap:
find /proc -maxdepth 2 -path "/proc/[0-9]*/status" -readable -exec awk -v FS=":" -v TOTSWP="$(cat /proc/swaps | sed 1d | awk 'BEGIN{sum=0} {sum=sum+$(NF-2)} END{print sum}')" '{process[$1]=$2;sub(/^[ \t]+/,"",process[$1]);} END {if(process["VmSwap"] && process["VmSwap"] != "0 kB") {used_swap=process["VmSwap"];sub(/[ a-zA-Z]+/,"",used_swap);percent=(used_swap/TOTSWP*100); printf "%10s %-30s %20s %6.2f%\n",process["Pid"],process["Name"],process["VmSwap"],percent} }' '{}' \; | awk '{print $(NF-2),$0}' | sort -hr | head | cut -d " " -f2-
Update synoinfo.conf to correct memory in MB (https://www.gbmb.org/gb-to-mb) for 8GB:
/etc/synoinfo.conf & /etc.defaults/synoinfo.conf
mem_default_mb="8192"
mem_max_mb="8192"
Do:
/usr/syno/share/synotuned/profiles/performance_throughput.conf
&
/usr/syno/share/synotuned/profiles/performance_latency.conf
Find
vm.swappiness=60
Change to:
vm.swappiness=10
edit: /etc.defaults/sysctl.conf
kernel.panic = 3
net.core.somaxconn = 65535
net.ipv4.tcp_tw_reuse = 1
fs.inotify.max_user_watches=1048576
#adjusted stuff here#
vm.overcommit_memory = 1
vm.swappiness=10
vm.dirty_background_ratio = 5
vm.dirty_ratio = 10
vm.vfs_cache_pressure = 50
# Increase size of file handles and inode cache
fs.file-max = 2097152
# tells the kernel how many TCP sockets that are not attached to any
# user file handle to maintain. In case this number is exceeded,
# orphaned connections are immediately reset and a warning is printed.
net.ipv4.tcp_max_orphans = 60000
# Do not cache metrics on closing connections
net.ipv4.tcp_no_metrics_save = 1
# Turn on window scaling which can enlarge the transfer window:
net.ipv4.tcp_window_scaling = 1
# Enable timestamps as defined in RFC1323:
net.ipv4.tcp_timestamps = 1
# Enable select acknowledgments:
net.ipv4.tcp_sack = 1
# Maximum number of remembered connection requests, which did not yet
# receive an acknowledgment from connecting client.
net.ipv4.tcp_max_syn_backlog = 10240
# recommended default congestion control is htcp
net.ipv4.tcp_congestion_control=htcp
# recommended for hosts with jumbo frames enabled
net.ipv4.tcp_mtu_probing=1
# Number of times SYNACKs for passive TCP connection.
net.ipv4.tcp_synack_retries = 2
# Allowed local port range
net.ipv4.ip_local_port_range = 1024 65535
# Protect Against TCP Time-Wait
net.ipv4.tcp_rfc1337 = 1
# Decrease the time default value for tcp_fin_timeout connection
net.ipv4.tcp_fin_timeout = 15
# Increase number of incoming connections
# somaxconn defines the number of request_sock structures
# allocated per each listen call. The
# queue is persistent through the life of the listen socket.
net.core.somaxconn = 1024
# Increase number of incoming connections backlog queue
# Sets the maximum number of packets, queued on the INPUT
# side, when the interface receives packets faster than
# kernel can process them.
net.core.netdev_max_backlog = 65536
# Increase the maximum amount of option memory buffers
net.core.optmem_max = 25165824
# Increase the maximum total buffer-space allocatable
# This is measured in units of pages (4096 bytes)
net.ipv4.tcp_mem = 65536 131072 262144
net.ipv4.udp_mem = 65536 131072 262144
### Set the max OS send buffer size (wmem) and receive buffer
# size (rmem) to 12 MB for queues on all protocols. In other
# words set the amount of memory that is allocated for each
# TCP socket when it is opened or created while transferring files
# Default Socket Receive Buffer
net.core.rmem_default = 25165824
# Maximum Socket Receive Buffer
net.core.rmem_max = 25165824
# Increase the read-buffer space allocatable (minimum size,
# initial size, and maximum size in bytes)
net.ipv4.tcp_rmem = 20480 12582912 25165824
net.ipv4.udp_rmem_min = 16384
# Default Socket Send Buffer
net.core.wmem_default = 25165824
# Maximum Socket Send Buffer
net.core.wmem_max = 25165824
# Increase the write-buffer-space allocatable
net.ipv4.tcp_wmem = 20480 12582912 25165824
net.ipv4.udp_wmem_min = 16384
# Increase the tcp-time-wait buckets pool size to prevent simple DOS attacks
net.ipv4.tcp_max_tw_buckets = 1440000
# net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
# disable ipv6 as i dont use it
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
@imavroukakis I switched to truenas