Is this normal to enable fscache?

[yulinor]

OS debian 12.9
Kernel 6.11.10+bpo-amd64

Follow https://github.com/dragonflyoss/nydus/blob/master/docs/nydus-fscache.md

$ apt install cachefilesd
$ systemctl start cachefilesd
$ [ -c /dev/cachefiles ] && echo ok
$ lsof /dev/cachefiles
lsof: status error on /dev/cachefiles: No such file or directory

$  journalctl -f -u cachefilesd
Feb 07 16:54:36 yulinor systemd[1]: Starting cachefilesd.service - LSB: CacheFiles daemon...
Feb 07 16:54:36 yulinor cachefilesd[594]: cachefilesd disabled, please set RUN=yes in /etc/default/cachefilesd ... failed!
Feb 07 16:54:36 yulinor systemd[1]: Started cachefilesd.service - LSB: CacheFiles daemon.

# modify config,Remove comment symbols
$ vim  /etc/default/cachefilesd
# old 
# RUN=yes
# new
RUN=yes

$ systemctl restart cachefilesd
$ lsof /dev/cachefiles
COMMAND    PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
cachefile 1995 root    3u   CHR 10,123      0t0  538 /dev/cachefiles
$ [ -c /dev/cachefiles ] && echo ok
ok

so,Is this normal to enable fscache?

There is a sentence in the article: Ensure the device file /dev/cachefiles is not occupied. If your result is not empty, please kill all processes the result shows.

Does this mean I still need to kill the cachefile process?
Or is there another problem with this?

[hsiangkao]

the cachefile process needs to be killed, since it's incompatible with erofs+fscache feature.

[yulinor]

the cachefile process needs to be killed, since it's incompatible with erofs+fscache feature.

按照配置文档和nydus文档，我理解的是已经合并入5.19内核了，所以默认就Linux启动相关模块就能支持到这个erofs over fscache模式。
我刚才注释了RUN=yes重启服务器，确认回到了lsof提示No such file or directory后执行了如下步骤

root@yulinor:~# cat /proc/modules | grep cachefiles
root@yulinor:~# modprobe cachefiles
root@yulinor:~# cat /proc/modules | grep cachefiles
cachefiles 172032 0 - Live 0xffffffffc0bcd000
netfs 552960 1 cachefiles, Live 0xffffffffc0b26000
root@yulinor:~# [ -c /dev/cachefiles ] && echo ok
ok
root@yulinor:~# cat /boot/config-6.11.10+bpo-amd64 |grep -i CONFIG_EROFS_FS^C
root@yulinor:~# lsof /dev/cachefiles
root@yulinor:~#

这样的步骤倒是可以与文档保持一致。
所以文档是不是还要更新说明下启动模块？anolisos8.9（kernel config-5.10.134-13）没有验证模块命令，不过我看了下[ -c /dev/cachefiles ] && echo ok没有输出，且lsof也是No such file or directory

[hsiangkao]

apt install cachefilesd is NOT needed, erofs fscache doesn't use cachefilesd itself.

anolis kernel 5.10.134-13 is too old kernel, you should use a newer kernel instead.

[yulinor]

apt install cachefilesd is NOT needed, erofs fscache doesn't use cachefilesd itself.

anolis kernel 5.10.134-13 is too old kernel, you should use a newer kernel instead.

如果不需要 cachefilesd ，那这文档是否有点过时了？

[hsiangkao]

apt install cachefilesd is NOT needed, erofs fscache doesn't use cachefilesd itself.
anolis kernel 5.10.134-13 is too old kernel, you should use a newer kernel instead.

如果不需要 cachefilesd ，那这文档是否有点过时了？

There is a bad commit cdc41de

[yulinor]

apt install cachefilesd is NOT needed, erofs fscache doesn't use cachefilesd itself.
anolis kernel 5.10.134-13 is too old kernel, you should use a newer kernel instead.

如果不需要 cachefilesd ，那这文档是否有点过时了？

There is a bad commit cdc41de

期待更新一份正确的、完整验证步骤的配置文档。

[hsiangkao]

你可以适用后提个PR更新下手册。