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| supported_devices:432_warning [2020/01/17 16:21] – [Supportability issues] 19.07 will be the last release for 4/32 devices tmomas | supported_devices:432_warning [2021/11/29 01:38] – [Warning about 4/32 devices] richb-hanover | ||
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| Line 1: | Line 1: | ||
| - | ====== 4/32 warning | + | ====== |
| ~~NOTOC~~ | ~~NOTOC~~ | ||
| - | |||
| - | Every operating system requires | ||
| - | - Sufficient Flash to accommodate firmware image | ||
| - | - Sufficient RAM for stable operation | ||
| <WRAP round info 100%> | <WRAP round info 100%> | ||
| - | **Devices with ≤4MB flash and/or ≤32MB | + | **TL;DR - Devices with ≤4MB flash and/or ≤32MB |
| </ | </ | ||
| - | ===== Usability issues===== | + | Default builds of OpenWrt 21.02 can only run on 8/64 devices. We **recommend 16/128 devices.** Every operating system requires: |
| + | - Sufficient RAM for stable operation | ||
| + | - Sufficient Flash to accommodate the firmware image | ||
| - | **Insufficient | + | ===== Low RAM can lead to instability ===== |
| - | * 32 MB can work for minimal router/AP functions, but may repeatedly " | + | * 32 MB can barely |
| * 64 MB may still have issues with stability, depending on your hardware and use cases | * 64 MB may still have issues with stability, depending on your hardware and use cases | ||
| - | * 128 MB or more is recommended if software past basic router/AP functionality is to be used | + | * 128 MB or more is recommended |
| - | ===== Extensibility issues | + | ===== Low Flash can't load new firmware or new packages |
| - | **Barely enough Flash to accommodate OpenWrt firmware image** | + | |
| - | + | ||
| - | | + | |
| - | * 4MB can work, but are no fun to work with. >4MB will make you happier than 4MB or below. | + | |
| * 4MB devices can't fit anything noteworthy unless you use [[docs: | * 4MB devices can't fit anything noteworthy unless you use [[docs: | ||
| - | * If you want to be sure you can install at least a few additional software packages, | + | * 8MB (or more) of Flash lets install at least a few additional software packages, |
| + | * 16MB Flash (minimum) is recommended for the foreseeable future | ||
| Most probably, you will not be able to install the following popular packages (and others) on a device with only 4MB flash: | Most probably, you will not be able to install the following popular packages (and others) on a device with only 4MB flash: | ||
| Line 34: | Line 30: | ||
| * filesystem drivers/ | * filesystem drivers/ | ||
| + | As the current stable 21.02 release uses kernel 5.4 that is roughly 0.5 MB larger than the kernel 4.14 used in the old 19.07.x releases, and SSL/HTTPS has been enabled by default needing at least some 0.3 MB flash space for the SSL libraries, the free flash space available on 8MB flash systems will be rather small in the current OpenWrt 21.02 release. OpenWrt master has already partially moved to kernel 5.10, which is still larger. | ||
| ===== Supportability issues ===== | ===== Supportability issues ===== | ||
| - | It is getting harder or even impossible over time to support devices with low Flash + RAM. | + | It is getting harder or even impossible over time to support devices with low Flash + RAM. You will be less likely to find people willing to assist on the forums. |
| - | **OpenWrt support for those devices will end with the 19.07 release**, ie. 19.07 will be the last release with support for 4/32 MB devices. There will be no future releases and no images ready for download after 19.07. | + | |
| + | The 32 MB RAM is harder limitation than the flash size. The current Linux 5.4 barely works with a 32 MB RAM system and spikes in memory consumption can easily crash the router with OOM (Out-of-Memory) errors. | ||
| + | |||
| + | **OpenWrt support for those devices will end with the 19.07 release**, ie. 19.07 will be the last release with support for 4/32 MB devices. There will be no future releases and no images ready for download after 19.07. | ||
| ===== Advice ===== | ===== Advice ===== | ||
| - | Users that are not expert | + | If you are not an expert |
| **16/64 as an // | **16/64 as an // | ||
| - | Users should expect that devices with less than 16 MB of flash and/or 64 MB of RAM may be unstable in basic operation under current versions of OpenWrt (17.X, 18.X). They should further | + | If a device has less than 16 MB of Flash and/ |
| + | |||
| + | Previous versions of OpenWrt (such as earlier versions of 18.06.x, 17.01.x, 15.05.x "Chaos Calmer" | ||
| + | |||
| + | |||
| + | ===== Analysis of firmware size growth ===== | ||
| + | |||
| + | As example, the size of the sysupgrade release image for WNDR3700v1, an ar71xx/ | ||
| + | |||
| + | < | ||
| + | master: | ||
| + | 21.02.0: | ||
| + | 19.07.8: | ||
| + | 18.06.8: | ||
| + | 17.01.7: | ||
| + | 15.05.1: | ||
| + | 14.07: | ||
| + | 12.09: | ||
| + | </ | ||
| + | |||
| + | Main reason is growth in size of the Linux kernel itself, but all included core packages (wifi, LuCI, etc.) also tend to grow as their features get expanded. | ||
| - | Previous versions | + | ==== Longer analysis |
| - | ===== An analysis of the issue done by forum user slh ===== | ||
| As written in [[https:// | As written in [[https:// | ||