Not persistent across reboots

[TheLinuxGuy]

Thanks for making this script available. I have followed the setup instructions and upon reboot (regardless of sysctl.conf setting for 0 instead of 1024 the DSM seems to be resetting it to defaults).

Here is some basic debugging after a reboot, note I installed using the script run as root (sudo -i) before rebooting.

myuser@sin:/$ sudo -i
root@sin:~# date
Sat Feb  3 03:29:12 AM EST 2024
root@sin:~# uptime
 03:29:14 up 1 min,  1 user,  load average: 5.34, 1.84, 0.66 [IO: 3.79, 1.22, 0.43 CPU: 1.55, 0.62, 0.23]
root@sin:~# cat /etc/sy
synoappprivilege.db     synoinfo.conf.16tlG0    synotoprc               sysctl.conf
synoautoblock.db        synopackageslimit.conf  synouser.conf           syslog-ng/
synoinfo.conf           synosyslog/             sysconfig/              systemd/
root@sin:~# cat /etc/sysctl.conf
kernel.panic = 3
net.core.somaxconn = 65535
net.ipv4.tcp_tw_reuse  = 1
fs.protected_hardlinks = 1
fs.protected_symlinks = 1
kernel.syno_forbid_console=0
kernel.syno_forbid_usb=0
net.ipv6.conf.default.accept_ra_defrtr=0
net.ipv4.conf.default.accept_redirects=0
net.ipv6.conf.default.accept_redirects=0
net.ipv4.conf.default.send_redirects=0
net.ipv4.conf.default.secure_redirects=0
net.ipv6.conf.default.accept_ra=0
dev.flashcache_shared_cache_vg1_alloc_cache_1+volume_1.skip_seq_thresh_kb="0"
(failed reverse-i-search)`dev': ^Cte
root@sin:~# /volume1/data/synology/scripts/
@eaDir/            syno_app_mover.sh  syno_seq_io.sh
root@sin:~# /volume1/data/synology/scripts/syno_seq_io.sh
Synology_enable_sequential_IO v1.0.1 - by 007revad

See https://github.com/007revad/Synology_enable_sequential_IO

Setting a cache's skip_seq_thresh_kb to 0 enables sequential I/O
Choose a volume with a cache to edit:
---------------------
Cache Volume  Setting
---------------------
1)  volume_1  1024
---------------------
Select cache volume to edit: 1

You selected volume_1 to set to 0

Sequential I/O for volume_1 cache is enabled.

The Synology needs to restart.
Type yes to reboot now.
Type anything else to quit (if you will restart it yourself).

[TheLinuxGuy]

My workaround for now.

root@sin:~# cat /proc/sys/dev/flashcache_shared_cache_vg1_alloc_cache_1+volume_1/skip_seq_thresh_kb
1024
root@sin:~# echo "0" > /proc/sys/dev/flashcache_shared_cache_vg1_alloc_cache_1+volume_1/skip_seq_thresh_kb
root@sin:~# cat /proc/sys/dev/flashcache_shared_cache_vg1_alloc_cache_1+volume_1/skip_seq_thresh_kb
0

Verified working; otherwise the NAS won't write to nvme sequential IO (7GB linux dvd iso)

[007revad]

Are you using DSM 7.2.1 Update 4?

[TheLinuxGuy]

Are you using DSM 7.2.1 Update 4?

No.

DSM 7.2.1-69057 Update 3 (Release notes) on DS1522+

[skupjoe]

I am seeing the same issue and I am running DSM 7.2.1-69057 Update 3 on DS1823xs+

After running the script and setting to 0 I immediately re-run the script and I still see a value of 1024.

# ./syno_seq_io.sh                                                                                                                                        
Synology_enable_sequential_IO v1.0.1 - by 007revad                                                         

See https://github.com/007revad/Synology_enable_sequential_IO                                              

Setting a cache's skip_seq_thresh_kb to 0 enables sequential I/O                                           
Choose a volume with a cache to edit:                                                                      
---------------------                                                                                      
Cache Volume  Setting                                                                                      
---------------------                                                                                      
1)  volume_1  1024                                                                                         
---------------------                                                                                      
Select cache volume to edit: 1                                                                             

You selected volume_1 to set to 0                                                                          

Sequential I/O for volume_1 cache is enabled.                                                              

The Synology needs to restart.                                                                             
Type yes to reboot now.                                                                                    
Type anything else to quit (if you will restart it yourself).              
<no reboot>

# cat /proc/sys/dev/flashcache_shared_cache_vg1_alloc_cache_1+volume_1/skip_seq_thresh_kb                                                                                                                                                                                                                                                                                       
1024                                                                

# ./syno_seq_io.sh                                                                                                                                        
Synology_enable_sequential_IO v1.0.1 - by 007revad                                                         

See https://github.com/007revad/Synology_enable_sequential_IO                                              

Setting a cache's skip_seq_thresh_kb to 0 enables sequential I/O                                           
Choose a volume with a cache to edit:                                                                      
---------------------                                                                                      
Cache Volume  Setting                                                                                      
---------------------                                                                                      
1)  volume_1  1024                                                                                         
---------------------                                                                                      
Select cache volume to edit: 1                                                                             

You selected volume_1 to set to 0                                                                          

Sequential I/O for volume_1 cache is enabled.                       

But if I run:

echo "0" > /proc/sys/dev/flashcache_shared_cache_vg1_alloc_cache_1+volume_1/skip_seq_thresh_kb

And then run the script immediately after (no reboot) I see it correctly set to 0:

# ./syno_seq_io.sh 
Synology_enable_sequential_IO v1.0.1 - by 007revad

See https://github.com/007revad/Synology_enable_sequential_IO 

Setting a cache's skip_seq_thresh_kb to `0` enables sequential I/O
Choose a volume with a cache to edit: 
---------------------
Cache Volume  Setting
---------------------
1)  volume_1  0
---------------------
Select cache volume to edit: q
Invalid choice! q

But then if I reboot it goes back to 1024.

# cat /proc/sys/dev/flashcache_shared_cache_vg1_alloc_cache_1+volume_1/skip_seq_thresh_kb                                                                                                                                                                                                                                                                                       
1024  

# ./syno_seq_io.sh                                                                                                                                        
Synology_enable_sequential_IO v1.0.1 - by 007revad                                                         

See https://github.com/007revad/Synology_enable_sequential_IO                                              

Setting a cache's skip_seq_thresh_kb to 0 enables sequential I/O                                           
Choose a volume with a cache to edit:                                                                      
---------------------                                                                                      
Cache Volume  Setting                                                                                      
---------------------                                                                                      
1)  volume_1  1024                                                                                         
---------------------

I've worked around this by using a scheduled boot task to run:

echo "0" > /proc/sys/dev/flashcache_shared_cache_vg1_alloc_cache_1+volume_1/skip_seq_thresh_kb

[007revad]

@TheLinuxGuy @skupjoe

My Internet was down for 4 hours today so I had time to work on this script. The version I'm working on:

1. Includes echo "0" > /proc/sys/dev/flashcache_shared_cache_vg1_alloc_cache_1+volume_1/skip_seq_thresh_kb for the selected volume.
2. Does not need a reboot after running running the script due to point 1.

I'm currently working on making it possible to schedule the script to run at boot with an option to specify the caches you want set to sequential I/O.

[007revad]

New version of the script here: https://github.com/007revad/Synology_enable_sequential_IO/releases/tag/v2.0.3

It needs to be scheduled to run as root at boot, with the --volumes=volume_n option.

See readme: https://github.com/007revad/Synology_enable_sequential_IO
and how to scheduled: https://github.com/007revad/Synology_enable_sequential_IO/blob/main/how_to_schedule.md