I am tired of seeing this in my logs. I tried following google results on how to raise it but they do not seem to be unraid-specific and do not work/persist after a reboot. I do not know which container it is but it really doesn't matter, how do I raise this value properly?

Thanks

at first I thouhgt this to be a nginx / systemctl thing...

nope its good old php...
and potentail issues iwht fastcgi...

IDK what your doing to hit that and rasing the limit is not a fix to the under line issues...

Regardless, you will need a user script plugin and a script at frist array start to run to make this last between reboots..

cat /etc/php-fpm.d/www.conf

and look for : pm.max_children = 50

default should have:

; The number of child processes to be created when pm is set to 'static' and the

; maximum number of child processes when pm is set to 'dynamic' or 'ondemand'.

; This value sets the limit on the number of simultaneous requests that will be

; served. Equivalent to the ApacheMaxClients directive with mpm_prefork.

; Equivalent to the PHP_FCGI_CHILDREN environment variable in the original PHP

; CGI. The below defaults are based on a server without much resources. Don't

; forget to tweak pm.* to fit your needs.

; Note: Used when pm is set to 'static', 'dynamic' or 'ondemand'

; Note: This value is mandatory.

pm.max_children = 50

so at frist aray start user script plugn run:

#!/bin/bash
# Increase PHP-FPM max_children to handle more concurrent UI/API calls
# Run "At First Array Start" in User Scripts

PHP_FPM_CONF="/etc/php-fpm.d/www.conf"
NEW_LIMIT=200  # adjust as needed (default 50)

# Verify config exists
if [[ -f "$PHP_FPM_CONF" ]]; then
    echo "Updating pm.max_children in $PHP_FPM_CONF to $NEW_LIMIT..."

    # Use sed to replace the line if it exists, otherwise append it
    if grep -q '^pm.max_children' "$PHP_FPM_CONF"; then
        sed -i "s/^pm.max_children.*/pm.max_children = ${NEW_LIMIT}/" "$PHP_FPM_CONF"
    else
        echo "pm.max_children = ${NEW_LIMIT}" >> "$PHP_FPM_CONF"
    fi

    # Restart PHP-FPM service safely
    /etc/rc.d/rc.php-fpm restart
    echo "PHP-FPM restarted with new limit: $NEW_LIMIT"
else
    echo "ERROR: $PHP_FPM_CONF not found. Unraid may have changed its path."
fi

this will increase the limit to 200...

However, again. this is not a fix!!! You need to figur out the memory leak that hitting the 50...

I ran that and get this output:

5 hours ago, paradox.actual said:

I ran that and get this output:

I can neither confirm the time you ran the script nor a issues with your screenshot log...

issues again is not the script nor a solution to increase the child max... (this is temp relief anyways...) as you have somthign calling and tyring to call a script...

You keep Necroing and going back between mutiple threads... Please keep to one forum post... for continued updates AND FOLLOW THE FORUM RULES!!!

MAKE A GENERAL POST AND POST DIAGS! IDK what your runing nor how your running to get in this state...

not enouth info to assist either way... you have to find the memory leak...

Common areas in testing. appdata backup plugin. overloaded system to many dockers vm running at once. Python and python code. and the unraid connect plugin...

Please post diag...
?When the last time you reboted teh server? What is it doing to end up in this state...?

Setup a system log server...

Would appreciate any help here as getting similar/same error since 7.2.2. Only thing that has really changed in past couple of months:

OS upgrade, FileBrowser Quantum installed, Regular Docker and Unraid Connect upgrades. Rebooted ~a day ago.

I do have a few things going on but figured I would start with this error which is becoming more frequent.

Edited December 29, 2025Dec 29 by goldbondx

2 hours ago, goldbondx said:

Would appreciate any help here as getting similar/same error since 7.2.2. Only thing that has really changed in past couple of months:

OS upgrade, FileBrowser Quantum installed, Regular Docker and Unraid Connect upgrades. Rebooted ~a day ago.

I do have a few things going on but figured I would start with this error which is becoming more frequent.

mcunraid-diagnostics-20251225-1235.zip

please make your own general post next time. THank you fro a diag.

you apear to have a bunch of sleeping fast-cgi calls stalled whcih hit the memory leak and a few error due to the unraid connect plugin...

This is my analsis of your logs

What the logs show (hard evidence)

1) php-fpm pool is repeatedly saturating at 50 children

Your syslog shows 25 occurrences of:

• php-fpm ... [pool www] server reached max_children setting (50)

spanning Dec 20 → Dec 25.

And your top.txt snapshot shows ~48 php-fpm processes running at once at the time the diagnostics were captured (so you were right at the ceiling).

Also, at least a couple of these happen immediately after WebGUI login, e.g.:

• Dec 24 12:32:01 ... Successful login user root from 192.168.30.35

• Dec 24 12:32:02 ... php-fpm ... server reached max_children (50)

That strongly suggests: loading the dashboard (and its background polling endpoints) triggers enough slow/stuck PHP work that the pool fills up.

---

2) Repeated nchan watchdog kills

Your syslog also shows repeated:

• monitor_nchan: Stop running nchan processes

on multiple days (Dec 21/22/23/24/25). nchan is what Unraid uses for “live updates”/streaming UI events. If nchan gets wedged (often because upstream requests stall), the watchdog kills it and restarts it.

This pairs really well with a “webgui becomes sluggish/unresponsive + php-fpm children pile up” story.

---

3) A very strong culprit: USB/UAS storage errors + resets (blocking I/O)

In syslog-previous.txt, when a 5TB WD drive in a SABRENT enclosure comes online, you get a burst of UAS + write I/O errors:

• scsi host5: uas

• Direct-Access SABRENT ...

• Disk: WDC_WD50EFRX... (sda)

• Then many:

  • I/O error, dev sda, sector ... (WRITE)

  • Sense Key : 0xb

  • ASC=0x4b ASCQ=0x0

  • uas_eh_abort_handler ... inflight

  • reset SuperSpeed USB device ...

  • uas_eh_device_reset_handler ... success

This is exactly the kind of thing that can stall processes waiting on disk, and the Unraid GUI does a lot of “query disks / SMART / mounts / shares” type work via PHP endpoints. If a PHP worker is blocked waiting on a disk op (or a plugin querying that disk), it doesn’t return, so you burn through children until you hit max_children.

So even if you call it “memory leak,” the logs look more like:

“FastCGI worker pool leak” (workers stuck) caused by USB storage I/O stalls (UAS/enclosure/cable/power/drive problems), possibly amplified by live-update polling (nchan).

---

What I’d do first (highest ROI)

A) Eliminate the USB/UAS problem first

If that SABRENT+WD50 device is still in the picture:

1. Unplug it and see if the php-fpm max_children events stop.

2. If you need it connected:

   • try a different cable/port/power path (USB power flakiness causes exactly this)

   • and/or disable UAS for that enclosure (common fix).

How to disable UAS (the right way):

• Plug the enclosure in and run:

  • lsusb

  • lsusb -t

• Identify the enclosure’s VID:PID (like aaaa:bbbb)

• Add a USB-storage quirk in your Syslinux append line:

  • usb-storage.quirks=aaaa:bbbb:u

• Reboot.

(Your diagnostics were captured after a reboot where that enclosure wasn’t present, so I can’t pull the VID:PID from this zip.)

B) Temporarily disable likely “UI poller” plugins to reduce pressure

Given your plugin list, I’d test disabling (one at a time) to see if max_children stops:

• Dynamix Active Streams

• Dynamix System Stats

• Unassigned Devices (especially if it’s touching that USB disk / remote mounts)

This is a quick way to confirm whether the “stuck requests” are coming from a plugin endpoint.

---

How to pinpoint which PHP endpoint is eating children (so you can prove it)

Right now the diagnostics don’t include nginx access logs or php-fpm slowlogs, so we can’t name the exact script. But you can make Unraid tell you:

1) Turn on php-fpm slowlog (captures stuck request backtraces + script names)

On Unraid this is typically /etc/php-fpm.d/www.conf (runtime filesystem), so it won’t persist unless you reapply on boot.

Add (or enable) something like:

• request_slowlog_timeout = 5s

• slowlog = /var/log/php-fpm.slow.log

• optionally: request_terminate_timeout = 60s (so truly stuck ones get killed)

Then restart php-fpm and wait for the next incident. The slowlog will usually reveal which PHP file/plugin is hanging.

2) Check nginx access logs during an event

When you’re hitting max_children, run:

• tail -f /var/log/nginx/access.log

• tail -f /var/log/nginx/error.log

You’ll often see one endpoint being hammered (or timing out) — e.g. a plugin page refresh endpoint.

---

Quick mitigation (not the real fix, but keeps GUI alive)

If you just raise pm.max_children, you may reduce symptoms but you’re also allowing more stuck workers, which can make the GUI feel “randomly dead” for longer if the root cause is blocking I/O.

Better mitigations:

• fix/remove the USB/UAS problem

• add php-fpm pm.max_requests (recycles workers to mitigate real leaks)

• add slowlog + terminate timeout to prevent indefinite worker hostage situations

Thanks for the quick reply on. The USB issue was dealt with. External drive bay (5 TB) that is failing regularly. It's garbage and throwing it out. Unfortunately, the errors were still happening even after reboot it looks like. I'll keep an eye.

The big issue trying to mitigate is item 1 (and 2) and thanks for clarifying root cause. I was unsure if GUI or something deeper. I wanted to confirm nothing that would impact data/writes. Item B seems like a good choice to start and eliminate polling culprits. I do have a bunch of dashboard elements as you mention.

I'll be honest. My Linux skills are limited. I have never touched NGINX and hesitant to mess around with the pm.max_requests or slowlog. Will do a bit more research.

My only remaining question. I haven't had any issues with this error up until the last 2 updates to OS. The only thing I have done is regular updates to Dockers and added FileBrowser Quantum. What could have introduced this?

Anything that calls a script...

This could be a mobile browser on the dash board, a script, unraid connect issues and errors, ud scrip auto mount. User script gone astray Dockers that wget/curl back from host to call... A unraid load issues with the monitor script for notify/syslog the script that loads the dash oards and refreshs... With out monitoring top/htop idk. You have to find the memory leak ...

This would be more of a fix but idk unRAID default fast CGI option...

optionally: request_terminate_timeout = 60s (so truly stuck ones get killed)

Recommend to kill the stale and zombie childs...

Removed my last post. I am not sure anymore on DelugeVPN as it seems this warning (max_children) popped up on every login as you suspected. It is somewhat inconsistent.

One critical follow-up question. Plug-ins are remove only. There is no ability to "disable" as mentioned? I tried removing Unassigned Devices as a test and received this:

Dec 29 11:40:41 mcunraid nginx: 2025/12/29 11:40:41 [error] 12364#12364: *109459 FastCGI sent in stderr: "Unable to open primary script: /usr/local/emhttp/plugins/unassigned.devices.preclear/include/Preclear.php (No such file or directory)" while reading response header from upstream, client: 1<Desktop Client IP>, server: , request: "POST /plugins/unassigned.devices.preclear/include/Preclear.php HTTP/2.0", upstream: "fastcgi://unix:/var/run/php-fpm.sock:", host: "<Unraid IP>", referrer: "https://<Unraid IP>/Plugins"

....... php-fpm[12253]: [WARNING] [pool www] server reached max_children setting (50), consider raising it

I quickly re-added the plug-in successfully.

I don't use NGINX at all. I access my server ext by VPN only. There is no reverse proxy.

Hesitant to go any deeper as do not feel my skills follow your entire recommendations.

Unassigned Devices Preclear and Unassigned Devices Plus are add-ons to Unassigned Devices. You would need to remove these first, then you can remove Unassigned Devices without receiving an error.

1 hour ago, ConnerVT said:

Unassigned Devices Preclear and Unassigned Devices Plus are add-ons to Unassigned Devices. You would need to remove these first, then you can remove Unassigned Devices without receiving an error.

I suspected that was the case and you indirectly confirmed that removal is only option. Thanks for the quick reply.

Yes, no way I know of to disable individual plugins. Rebooting in Safe Mode disables all of them, as well as Docker and VM services.

On 12/29/2025 at 2:14 PM, ConnerVT said:

Yes, no way I know of to disable individual plugins. Rebooting in Safe Mode disables all of them, as well as Docker and VM services.

OK it has been 3 days after removing unassigned drive and unassigned drive plus with no max_children message that I can see. That said, still flooded with avahi_key_new() failed. Moving on..

Update: So, I started tackling the Avahi error and low and behold the max_children error came back. All I did was rename a share with a blank in it, and it seem to come up during some additional log info.

This didn't exist before these last updates leading to 7.2.3. I don't know what is going on and not deep enough skills to fix them. What I do know, I am not the only 1 to report these problems.

Edited January 1Jan 1 by goldbondx

2 hours ago, goldbondx said:

OK it has been 3 days after removing unassigned drive and unassigned drive plus with no max_children message that I can see. That said, still flooded with avahi_key_new() failed. Moving on..

Update: So, I started tackling the Avahi error and low and behold the max_children error came back. All I did was rename a share with a blank in it, and it seem to come up during some additional log info.

This didn't exist before these last updates leading to 7.2.3. I don't know what is going on and not deep enough skills to fix them. What I do know, I am not the only 1 to report these problems.

edit the samba setting to match theses settings:

I'm not seeing this nor see how you get into these arears...

... fine lets edit fast-cgi... theres some htings to note as unraids emhttp server and its interaction with orginal nginx for https / fastcgi/php...

root@OMV:~# cat /etc/php-fpm.d/www.conf
; Start a new pool named 'www'.
; the variable $pool can be used in any directive and will be replaced by the
; pool name ('www' here)
[www]

; Per pool prefix
; It only applies on the following directives:
; - 'access.log'
; - 'slowlog'
; - 'listen' (unixsocket)
; - 'chroot'
; - 'chdir'
; - 'php_values'
; - 'php_admin_values'
; When not set, the global prefix (or /usr) applies instead.
; Note: This directive can also be relative to the global prefix.
; Default Value: none
;prefix = /path/to/pools/$pool

; Unix user/group of the child processes. This can be used only if the master
; process running user is root. It is set after the child process is created.
; The user and group can be specified either by their name or by their numeric
; IDs.
; Note: If the user is root, the executable needs to be started with
;       --allow-to-run-as-root option to work.
; Default Values: The user is set to master process running user by default.
;                 If the group is not set, the user's group is used.
; limetech - user/group is root
;user = nobody
;group = nobody
user = root
group = root

; The address on which to accept FastCGI requests.
; Valid syntaxes are:
;   'ip.add.re.ss:port'    - to listen on a TCP socket to a specific IPv4 address on
;                            a specific port;
;   '[ip:6:addr:ess]:port' - to listen on a TCP socket to a specific IPv6 address on
;                            a specific port;
;   'port'                 - to listen on a TCP socket to all addresses
;                            (IPv6 and IPv4-mapped) on a specific port;
;   '/path/to/unix/socket' - to listen on a unix socket.
; Note: This value is mandatory.
;limetech - listen at socket
;listen = 127.0.0.1:9000
listen = /var/run/php-fpm.sock                               

; Set listen(2) backlog.
; Default Value: 511 (-1 on Linux, FreeBSD and OpenBSD)
;listen.backlog = 511

; Set permissions for unix socket, if one is used. In Linux, read/write
; permissions must be set in order to allow connections from a web server. Many
; BSD-derived systems allow connections regardless of permissions. The owner
; and group can be specified either by name or by their numeric IDs.
; Default Values: Owner is set to the master process running user. If the group
;                 is not set, the owner's group is used. Mode is set to 0660.
;listen.owner = nobody
;listen.group = nobody
;listen.mode = 0660

; When POSIX Access Control Lists are supported you can set them using
; these options, value is a comma separated list of user/group names.
; When set, listen.owner and listen.group are ignored
;listen.acl_users =
;listen.acl_groups =

; List of addresses (IPv4/IPv6) of FastCGI clients which are allowed to connect.
; Equivalent to the FCGI_WEB_SERVER_ADDRS environment variable in the original
; PHP FCGI (5.2.2+). Makes sense only with a tcp listening socket. Each address
; must be separated by a comma. If this value is left blank, connections will be
; accepted from any ip address.
; Default Value: any
;listen.allowed_clients = 127.0.0.1

; Set the associated the route table (FIB). FreeBSD only
; Default Value: -1
;listen.setfib = 1

; Specify the nice(2) priority to apply to the pool processes (only if set)
; The value can vary from -19 (highest priority) to 20 (lower priority)
; Note: - It will only work if the FPM master process is launched as root
;       - The pool processes will inherit the master process priority
;         unless it specified otherwise
; Default Value: no set
; process.priority = -19

; Set the process dumpable flag (PR_SET_DUMPABLE prctl for Linux or
; PROC_TRACE_CTL procctl for FreeBSD) even if the process user
; or group is different than the master process user. It allows to create process
; core dump and ptrace the process for the pool user.
; Default Value: no
; process.dumpable = yes

; Choose how the process manager will control the number of child processes.
; Possible Values:
;   static  - a fixed number (pm.max_children) of child processes;
;   dynamic - the number of child processes are set dynamically based on the
;             following directives. With this process management, there will be
;             always at least 1 children.
;             pm.max_children      - the maximum number of children that can
;                                    be alive at the same time.
;             pm.start_servers     - the number of children created on startup.
;             pm.min_spare_servers - the minimum number of children in 'idle'
;                                    state (waiting to process). If the number
;                                    of 'idle' processes is less than this
;                                    number then some children will be created.
;             pm.max_spare_servers - the maximum number of children in 'idle'
;                                    state (waiting to process). If the number
;                                    of 'idle' processes is greater than this
;                                    number then some children will be killed.
;             pm.max_spawn_rate    - the maximum number of rate to spawn child
;                                    processes at once.
;  ondemand - no children are created at startup. Children will be forked when
;             new requests will connect. The following parameter are used:
;             pm.max_children           - the maximum number of children that
;                                         can be alive at the same time.
;             pm.process_idle_timeout   - The number of seconds after which
;                                         an idle process will be killed.
; Note: This value is mandatory.
; limetech - let's use ondemand
;pm = dynamic
pm = ondemand

; The number of child processes to be created when pm is set to 'static' and the
; maximum number of child processes when pm is set to 'dynamic' or 'ondemand'.
; This value sets the limit on the number of simultaneous requests that will be
; served. Equivalent to the ApacheMaxClients directive with mpm_prefork.
; Equivalent to the PHP_FCGI_CHILDREN environment variable in the original PHP
; CGI. The below defaults are based on a server without much resources. Don't
; forget to tweak pm.* to fit your needs.
; Note: Used when pm is set to 'static', 'dynamic' or 'ondemand'
; Note: This value is mandatory.
pm.max_children = 50

; The number of child processes created on startup.
; Note: Used only when pm is set to 'dynamic'
; Default Value: (min_spare_servers + max_spare_servers) / 2
pm.start_servers = 2

; The desired minimum number of idle server processes.
; Note: Used only when pm is set to 'dynamic'
; Note: Mandatory when pm is set to 'dynamic'
pm.min_spare_servers = 1

; The desired maximum number of idle server processes.
; Note: Used only when pm is set to 'dynamic'
; Note: Mandatory when pm is set to 'dynamic'
pm.max_spare_servers = 3

; The number of rate to spawn child processes at once.
; Note: Used only when pm is set to 'dynamic'
; Note: Mandatory when pm is set to 'dynamic'
; Default Value: 32
;pm.max_spawn_rate = 32

; The number of seconds after which an idle process will be killed.
; Note: Used only when pm is set to 'ondemand'
; Default Value: 10s
;pm.process_idle_timeout = 10s;

; The number of requests each child process should execute before respawning.
; This can be useful to work around memory leaks in 3rd party libraries. For
; endless request processing specify '0'. Equivalent to PHP_FCGI_MAX_REQUESTS.
; Default Value: 0
pm.max_requests = 500

; The URI to view the FPM status page. If this value is not set, no URI will be
; recognized as a status page. It shows the following information:
;   pool                 - the name of the pool;
;   process manager      - static, dynamic or ondemand;
;   start time           - the date and time FPM has started;
;   start since          - number of seconds since FPM has started;
;   accepted conn        - the number of request accepted by the pool;
;   listen queue         - the number of request in the queue of pending
;                          connections (see backlog in listen(2));
;   max listen queue     - the maximum number of requests in the queue
;                          of pending connections since FPM has started;
;   listen queue len     - the size of the socket queue of pending connections;
;   idle processes       - the number of idle processes;
;   active processes     - the number of active processes;
;   total processes      - the number of idle + active processes;
;   max active processes - the maximum number of active processes since FPM
;                          has started;
;   max children reached - number of times, the process limit has been reached,
;                          when pm tries to start more children (works only for
;                          pm 'dynamic' and 'ondemand');
; Value are updated in real time.
; Example output:
;   pool:                 www
;   process manager:      static
;   start time:           01/Jul/2011:17:53:49 +0200
;   start since:          62636
;   accepted conn:        190460
;   listen queue:         0
;   max listen queue:     1
;   listen queue len:     42
;   idle processes:       4
;   active processes:     11
;   total processes:      15
;   max active processes: 12
;   max children reached: 0
;
; By default the status page output is formatted as text/plain. Passing either
; 'html', 'xml' or 'json' in the query string will return the corresponding
; output syntax. Example:
;   http://www.foo.bar/status
;   http://www.foo.bar/status?json
;   http://www.foo.bar/status?html
;   http://www.foo.bar/status?xml
;
; By default the status page only outputs short status. Passing 'full' in the
; query string will also return status for each pool process.
; Example:
;   http://www.foo.bar/status?full
;   http://www.foo.bar/status?json&full
;   http://www.foo.bar/status?html&full
;   http://www.foo.bar/status?xml&full
; The Full status returns for each process:
;   pid                  - the PID of the process;
;   state                - the state of the process (Idle, Running, ...);
;   start time           - the date and time the process has started;
;   start since          - the number of seconds since the process has started;
;   requests             - the number of requests the process has served;
;   request duration     - the duration in µs of the requests;
;   request method       - the request method (GET, POST, ...);
;   request URI          - the request URI with the query string;
;   content length       - the content length of the request (only with POST);
;   user                 - the user (PHP_AUTH_USER) (or '-' if not set);
;   script               - the main script called (or '-' if not set);
;   last request cpu     - the %cpu the last request consumed
;                          it's always 0 if the process is not in Idle state
;                          because CPU calculation is done when the request
;                          processing has terminated;
;   last request memory  - the max amount of memory the last request consumed
;                          it's always 0 if the process is not in Idle state
;                          because memory calculation is done when the request
;                          processing has terminated;
; If the process is in Idle state, then informations are related to the
; last request the process has served. Otherwise informations are related to
; the current request being served.
; Example output:
;   ************************
;   pid:                  31330
;   state:                Running
;   start time:           01/Jul/2011:17:53:49 +0200
;   start since:          63087
;   requests:             12808
;   request duration:     1250261
;   request method:       GET
;   request URI:          /test_mem.php?N=10000
;   content length:       0
;   user:                 -
;   script:               /home/fat/web/docs/php/test_mem.php
;   last request cpu:     0.00
;   last request memory:  0
;
; Note: There is a real-time FPM status monitoring sample web page available
;       It's available in: /usr/share/fpm/status.html
;
; Note: The value must start with a leading slash (/). The value can be
;       anything, but it may not be a good idea to use the .php extension or it
;       may conflict with a real PHP file.
; Default Value: not set
;pm.status_path = /status

; The address on which to accept FastCGI status request. This creates a new
; invisible pool that can handle requests independently. This is useful
; if the main pool is busy with long running requests because it is still possible
; to get the status before finishing the long running requests.
;
; Valid syntaxes are:
;   'ip.add.re.ss:port'    - to listen on a TCP socket to a specific IPv4 address on
;                            a specific port;
;   '[ip:6:addr:ess]:port' - to listen on a TCP socket to a specific IPv6 address on
;                            a specific port;
;   'port'                 - to listen on a TCP socket to all addresses
;                            (IPv6 and IPv4-mapped) on a specific port;
;   '/path/to/unix/socket' - to listen on a unix socket.
; Default Value: value of the listen option
;pm.status_listen = 127.0.0.1:9001

; The ping URI to call the monitoring page of FPM. If this value is not set, no
; URI will be recognized as a ping page. This could be used to test from outside
; that FPM is alive and responding, or to
; - create a graph of FPM availability (rrd or such);
; - remove a server from a group if it is not responding (load balancing);
; - trigger alerts for the operating team (24/7).
; Note: The value must start with a leading slash (/). The value can be
;       anything, but it may not be a good idea to use the .php extension or it
;       may conflict with a real PHP file.
; Default Value: not set
;ping.path = /ping

; This directive may be used to customize the response of a ping request. The
; response is formatted as text/plain with a 200 response code.
; Default Value: pong
;ping.response = pong

; The access log file
; Default: not set
;access.log = log/$pool.access.log

; The access log format.
; The following syntax is allowed
;  %%: the '%' character
;  %C: %CPU used by the request
;      it can accept the following format:
;      - %{user}C for user CPU only
;      - %{system}C for system CPU only
;      - %{total}C  for user + system CPU (default)
;  %d: time taken to serve the request
;      it can accept the following format:
;      - %{seconds}d (default)
;      - %{milliseconds}d
;      - %{milli}d
;      - %{microseconds}d
;      - %{micro}d
;  %e: an environment variable (same as $_ENV or $_SERVER)
;      it must be associated with embraces to specify the name of the env
;      variable. Some examples:
;      - server specifics like: %{REQUEST_METHOD}e or %{SERVER_PROTOCOL}e
;      - HTTP headers like: %{HTTP_HOST}e or %{HTTP_USER_AGENT}e
;  %f: script filename
;  %l: content-length of the request (for POST request only)
;  %m: request method
;  %M: peak of memory allocated by PHP
;      it can accept the following format:
;      - %{bytes}M (default)
;      - %{kilobytes}M
;      - %{kilo}M
;      - %{megabytes}M
;      - %{mega}M
;  %n: pool name
;  %o: output header
;      it must be associated with embraces to specify the name of the header:
;      - %{Content-Type}o
;      - %{X-Powered-By}o
;      - %{Transfert-Encoding}o
;      - ....
;  %p: PID of the child that serviced the request
;  %P: PID of the parent of the child that serviced the request
;  %q: the query string
;  %Q: the '?' character if query string exists
;  %r: the request URI (without the query string, see %q and %Q)
;  %R: remote IP address
;  %s: status (response code)
;  %t: server time the request was received
;      it can accept a strftime(3) format:
;      %d/%b/%Y:%H:%M:%S %z (default)
;      The strftime(3) format must be encapsulated in a %{<strftime_format>}t tag
;      e.g. for a ISO8601 formatted timestring, use: %{%Y-%m-%dT%H:%M:%S%z}t
;  %T: time the log has been written (the request has finished)
;      it can accept a strftime(3) format:
;      %d/%b/%Y:%H:%M:%S %z (default)
;      The strftime(3) format must be encapsulated in a %{<strftime_format>}t tag
;      e.g. for a ISO8601 formatted timestring, use: %{%Y-%m-%dT%H:%M:%S%z}t
;  %u: remote user
;
; Default: "%R - %u %t \"%m %r\" %s"
;access.format = "%R - %u %t \"%m %r%Q%q\" %s %f %{milli}d %{kilo}M %C%%"

; A list of request_uri values which should be filtered from the access log.
;
; As a security precuation, this setting will be ignored if:
;     - the request method is not GET or HEAD; or
;     - there is a request body; or
;     - there are query parameters; or
;     - the response code is outwith the successful range of 200 to 299
;
; Note: The paths are matched against the output of the access.format tag "%r".
;       On common configurations, this may look more like SCRIPT_NAME than the
;       expected pre-rewrite URI.
;
; Default Value: not set
;access.suppress_path[] = /ping
;access.suppress_path[] = /health_check.php

; The log file for slow requests
; Default Value: not set
; Note: slowlog is mandatory if request_slowlog_timeout is set
;slowlog = log/$pool.log.slow

; The timeout for serving a single request after which a PHP backtrace will be
; dumped to the 'slowlog' file. A value of '0s' means 'off'.
; Available units: s(econds)(default), m(inutes), h(ours), or d(ays)
; Default Value: 0
;request_slowlog_timeout = 0

; Depth of slow log stack trace.
; Default Value: 20
;request_slowlog_trace_depth = 20

; The timeout for serving a single request after which the worker process will
; be killed. This option should be used when the 'max_execution_time' ini option
; does not stop script execution for some reason. A value of '0' means 'off'.
; Available units: s(econds)(default), m(inutes), h(ours), or d(ays)
; Default Value: 0
;request_terminate_timeout = 0

; The timeout set by 'request_terminate_timeout' ini option is not engaged after
; application calls 'fastcgi_finish_request' or when application has finished and
; shutdown functions are being called (registered via register_shutdown_function).
; This option will enable timeout limit to be applied unconditionally
; even in such cases.
; Default Value: no
;request_terminate_timeout_track_finished = no

; Set open file descriptor rlimit.
; Default Value: system defined value
;rlimit_files = 1024

; Set max core size rlimit.
; Possible Values: 'unlimited' or an integer greater or equal to 0
; Default Value: system defined value
;rlimit_core = 0

; Chroot to this directory at the start. This value must be defined as an
; absolute path. When this value is not set, chroot is not used.
; Note: you can prefix with '$prefix' to chroot to the pool prefix or one
; of its subdirectories. If the pool prefix is not set, the global prefix
; will be used instead.
; Note: chrooting is a great security feature and should be used whenever
;       possible. However, all PHP paths will be relative to the chroot
;       (error_log, sessions.save_path, ...).
; Default Value: not set
;chroot =

; Chdir to this directory at the start.
; Note: relative path can be used.
; Default Value: current directory or / when chroot
;chdir = /var/www

; Redirect worker stdout and stderr into main error log. If not set, stdout and
; stderr will be redirected to /dev/null according to FastCGI specs.
; Note: on highloaded environment, this can cause some delay in the page
; process time (several ms).
; Default Value: no
;catch_workers_output = yes

; Decorate worker output with prefix and suffix containing information about
; the child that writes to the log and if stdout or stderr is used as well as
; log level and time. This options is used only if catch_workers_output is yes.
; Settings to "no" will output data as written to the stdout or stderr.
; Default value: yes
;decorate_workers_output = no

; Clear environment in FPM workers
; Prevents arbitrary environment variables from reaching FPM worker processes
; by clearing the environment in workers before env vars specified in this
; pool configuration are added.
; Setting to "no" will make all environment variables available to PHP code
; via getenv(), $_ENV and $_SERVER.
; Default Value: yes
;clear_env = no

; Limits the extensions of the main script FPM will allow to parse. This can
; prevent configuration mistakes on the web server side. You should only limit
; FPM to .php extensions to prevent malicious users to use other extensions to
; execute php code.
; Note: set an empty value to allow all extensions.
; Default Value: .php
;security.limit_extensions = .php .php3 .php4 .php5 .php7

; Pass environment variables like LD_LIBRARY_PATH. All $VARIABLEs are taken from
; the current environment.
; Default Value: clean env
;env[HOSTNAME] = $HOSTNAME
;env[PATH] = /usr/local/bin:/usr/bin:/bin
;env[TMP] = /tmp
;env[TMPDIR] = /tmp
;env[TEMP] = /tmp

; Additional php.ini defines, specific to this pool of workers. These settings
; overwrite the values previously defined in the php.ini. The directives are the
; same as the PHP SAPI:
;   php_value/php_flag             - you can set classic ini defines which can
;                                    be overwritten from PHP call 'ini_set'.
;   php_admin_value/php_admin_flag - these directives won't be overwritten by
;                                     PHP call 'ini_set'
; For php_*flag, valid values are on, off, 1, 0, true, false, yes or no.

; Defining 'extension' will load the corresponding shared extension from
; extension_dir. Defining 'disable_functions' or 'disable_classes' will not
; overwrite previously defined php.ini values, but will append the new value
; instead.

; Note: path INI options can be relative and will be expanded with the prefix
; (pool, global or /usr)

; Default Value: nothing is defined by default except the values in php.ini and
;                specified at startup with the -d argument
;php_admin_value[sendmail_path] = /usr/sbin/sendmail -t -i -f [email protected]
;php_flag[display_errors] = off
;php_admin_value[error_log] = /var/log/fpm-php.www.log
;php_admin_flag[log_errors] = on
;php_admin_value[memory_limit] = 32M
; limetech - set our include path
php_value[include_path] = ".:/usr/local/emhttp"
root@OMV:~# 

Following the default config they ship some notes and caveats...

Your real problem: ondemand + no hard kill = saturation

default ships with:
pm = ondemand

pm.max_children = 50

With no request kill timeout enabled.

That means:

• A worker accepts a request

• If that request never returns, the worker never dies

• Enough of those → you hit 50 → everything stalls

This is classic Unraid / emhttp behavior when a PHP call touches:

• /mnt/user during disk spin-up

• a stalled Docker socket

• a dead plugin endpoint

• slow USB / FUSE filesystem

• blocking shell_exec()
  

The missing kill switch (this is what you want)

You must enable a hard timeout: request_terminate_timeout = 120s

Optionally track finished requests too (important for emhttp): request_terminate_timeout_track_finished = yes

Why this matters

• Even if PHP ignores max_execution_time

• Even if fastcgi_finish_request() was called

• Even if shutdown handlers hang

FPM will SIGTERM the worker anyway

This is the actual zombie killer. making the child pids...

How to prove what’s leaking or stuck (no guessing)
Watch live FPM state: pm.status_path = /fpm-status

then go to http://unraid ip/fpm-status?full

Look for:

• Workers stuck in Running state for long durations

• Same script path repeated

• High request duration, low request count

Regardless theres a memomory leak some where ...

so lets makse some safe tuning:
pm = ondemand

pm.max_children = 50

pm.process_idle_timeout = 10s

pm.max_requests = 200

request_terminate_timeout = 120s

request_terminate_timeout_track_finished = yes

so heres another user script to help idetfy and kils some zombie childs...

DO SO AT YOUR OWN RISK!!!

#!/bin/bash
# Unraid PHP-FPM hardening + diagnostics
# Run: At First Array Start

PHP_FPM_CONF="/etc/php-fpm.d/www.conf"

set_value() {
    local key="$1"
    local value="$2"

    if grep -qE "^[;[:space:]]*${key}[[:space:]]*=" "$PHP_FPM_CONF"; then
        sed -i -E "s|^[;[:space:]]*${key}[[:space:]]*=.*|${key} = ${value}|" "$PHP_FPM_CONF"
    else
        echo "${key} = ${value}" >> "$PHP_FPM_CONF"
    fi
}

if [[ -f "$PHP_FPM_CONF" ]]; then
    echo "Configuring PHP-FPM limits and status endpoint in $PHP_FPM_CONF"

    # Process model
    set_value "pm" "ondemand"
    set_value "pm.max_children" "50"
    set_value "pm.process_idle_timeout" "10s"
    set_value "pm.max_requests" "200"

    # Hung / zombie worker kill switches
    set_value "request_terminate_timeout" "120s"
    set_value "request_terminate_timeout_track_finished" "yes"

    # FPM status endpoint (read-only diagnostics)
    set_value "pm.status_path" "/fpm-status"

    # Restart PHP-FPM
    echo "Restarting PHP-FPM..."
    /etc/rc.d/rc.php-fpm restart

    echo "PHP-FPM configuration enforced successfully."
else
    echo "ERROR: $PHP_FPM_CONF not found. PHP-FPM may not be installed or path changed."
fi

and to add the fastcgi staus page as a link...

#!/bin/bash
# Unraid nginx FastCGI injection for PHP-FPM status
# Ensures correct /fpm-status location exists and is clean
# Run: At First Array Start

NGINX_LOCATIONS="/etc/nginx/conf.d/locations.conf"

read -r -d '' STATUS_BLOCK <<'EOF'
location = /fpm-status {
    include fastcgi_params;
    fastcgi_param SCRIPT_NAME /fpm-status;
    fastcgi_param SCRIPT_FILENAME /fpm-status;

    allow 192.168.0.0/16;
    deny all;
}
EOF

if [[ ! -f "$NGINX_LOCATIONS" ]]; then
    echo "ERROR: $NGINX_LOCATIONS not found."
    exit 1
fi

echo "Ensuring /fpm-status nginx location is correct..."

# Remove any existing /fpm-status block (clean slate)
sed -i '/location = \/fpm-status {/,/}/d' "$NGINX_LOCATIONS"

# Append the correct block
echo "$STATUS_BLOCK" >> "$NGINX_LOCATIONS"

# Test and reload nginx
if nginx -t; then
    nginx -s reload
    echo "nginx reloaded successfully with /fpm-status enabled."
else
    echo "ERROR: nginx config test failed. Status block not applied."
    exit 1
fi

Edited January 1Jan 1 by bmartino1
data example...

Thanks @bmartino1 . I am very hesitant to jump into scripts. However, this gave me some ideas where to start researching more.

1 comment I have as I continue to troubleshoot. GPU statistics are hammering 1-2 CPU cores (100%) like clockwork every 2-4 seconds. I verified this when I uninstalled gpu statistics plugin. The CPU usage went to <1 and stayed that way until I reinstalled and selected my RTX3070. Then the 1-2 CPU cores started bouncing to 100% again like clockwork.

I have deselected my card in GPU statistics and seems to have stabilized. I will start up the array and monitor for several hours.

It appears occurrences of [WARNING] [pool www] server reached max_children setting (50), consider raising it are indeed tied to load of Dashboard (specifically Main) in browser. Only occurrences thus far are tied to refresh or tab changes as I monitor real-time.

Edited January 5Jan 5 by goldbondx