OpenWrt/LEDE Project

  • Status New
  • Percent Complete
  • Task Type Bug Report
  • Category Base system
  • Assigned To No-one
  • Operating System All
  • Severity High
  • Priority Very Low
  • Reported Version Trunk
  • Due in Version Undecided
  • Due Date Undecided
  • Private
Attached to Project: OpenWrt/LEDE Project
Opened by Ansuel - 29.01.2018

FS#1311 - procd: mount /tmp with zram

Supply the following if possible:
- Device problem occurs on all device
- Software versions of OpenWrt/LEDE: Trunk

If i select this option in menuconfig, At the boot procd mount the wrong size of ram. I have 512mb of ram and procd mount only 11mb of ram. More detail here.

vortigont commented on 25.09.2018 12:57

i think this is the place where it goes wrong - max RAM size of 32Mb is hardcoded here;a=blob;f=initd/zram.c;h=b41bfd999ba2630f086cba140e5fdcd7aabfac6b;hb=HEAD#l46

And than it get's divided by 2, which results in about 16Mb minus EXT4 overhead;a=blob;f=initd/zram.c;h=b41bfd999ba2630f086cba140e5fdcd7aabfac6b;hb=HEAD#l98

Project Manager
Yousong Zhou commented on 25.09.2018 13:09

The changelog indicates that this is an intentional limit [1]. Add john to the thread ;)


vortigont commented on 25.09.2018 15:49

Well, maybe it's time to increase this limit a little bit :)

alexander commented on 25.10.2019 02:45

Is there any update for this? I have exactly the same problem that my tmp is only 16MB on a router with 4GB RAM available. This makes the system unusable for me. Can we raise severity and/or impact?

rdslw commented on 08.03.2020 10:41

This bug reportedly creates severe problems for any user who enable zram.

Reason is, that these days typical openwrt firmware size is 12..20MB, while at the same time hardcoded zram limit of 16MB, means actually around 11.5MB on tmp (because ext4 minimal journal we use is 1024 of 4096 block, being 4MB).

That means, after flashing device with zram enabled firmware you're unable to flash anything else (at least easily ;) because new firmware does not fit anymore on /tmp. Hence once you flash with zram enabled you can not reflash.

Multiple cases are reported on forums.

I propose (patch attached) to increase hardcoded limit to 64MB (from current of 16MB), WHILE leaving in place safety check that zram CAN NOT take more than half of ram. (NB: patch uses 128MB because later it is divided by 2).

Project Manager
Baptiste Jonglez commented on 13.03.2020 10:16

Please send the patch on the mailing list:

You need to add a description, etc.


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