Hi Guys, thank you for the references. I did a small lab testing of all the possibilities to have overlay to be located on the network share, namely iscsi, sshfs, nfs and cifs and would like to share the results with you.
What I did is very simple. I made a firmware with included one by one these network share access methods and checked the free blocks left after a first boot. This is the most important value in my case. Then I created an overlay on a network share, downloaded with opkg several packages (large and small) on it
mkdir /dnl && cd /dnl
opkg update
opkg install --download-only luci mc luci-ssl nano asterisk dawn mariadb-server php8
and installed those packages, measuring time of execution and cpu load.
The results are below.
What surprised me much is that sshfs left far way less free blocks for the user than nfs and cifs. I've thought that having dropbear in the firmware already installed, sshfs should be a tiny wrap-up for a dropbear. I was wrong. It either not a thin wrap-up, or not a wrap-up at all.
**open-iscsi:**
Free blocks after installation: 480
time -v opkg install --cache /dnl/ *.ipk
User time (seconds): 79.62
System time (seconds): 20.84
Percent of CPU this job got: 86%
Elapsed (wall clock) time (h:mm:ss or m:ss): 1m 56.27s
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 34656
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 94
Minor (reclaiming a frame) page faults: 176415
Voluntary context switches: 38607
Involuntary context switches: 33005
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
**sshfs:**
Free blocks after installation: 864
time -v opkg install --cache /dnl/ *.ipk
User time (seconds): 77.32
System time (seconds): 21.10
Percent of CPU this job got: 65%
Elapsed (wall clock) time (h:mm:ss or m:ss): 2m 30.77s
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 48272
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 322
Minor (reclaiming a frame) page faults: 172187
Voluntary context switches: 37709
Involuntary context switches: 32282
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
**nfs:**
Free blocks after installation: 1504
time -v opkg install --cache /dnl/ *.ipk
User time (seconds): 82.79
System time (seconds): 26.60
Percent of CPU this job got: 72%
Elapsed (wall clock) time (h:mm:ss or m:ss): 2m 29.97s
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 38112
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 427
Minor (reclaiming a frame) page faults: 184747
Voluntary context switches: 40550
Involuntary context switches: 49396
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
**cifs:**
Free blocks after installation: 1568
time -v opkg install --cache /dnl/ *.ipk
User time (seconds): 82.46
System time (seconds): 28.49
Percent of CPU this job got: 67%
Elapsed (wall clock) time (h:mm:ss or m:ss): 2m 44.41s
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 29440
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 578
Minor (reclaiming a frame) page faults: 182750
Voluntary context switches: 40182
Involuntary context switches: 48728
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
-- Dmitry