1ZRAM-GENERATOR(8) ZRAM-GENERATOR(8)
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6 zram-generator - Systemd unit generator for zram swap devices
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9 /usr/lib/systemd/system-generators/zram-generator TARGET_DIR [2RGET_DIR
10 3RGET_DIR]
11 /usr/lib/systemd/system-generators/zram-generator --setup-device DEVICE
12 /usr/lib/systemd/system-generators/zram-generator --reset-device DEVICE
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15 zram-generator is a generator that creates zram devices and systemd
16 units to configure, format, and enable swap on them.
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18 The generator will be invoked by systemd early at boot. The generator
19 will then:
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21 1. read configuration files from {/etc,/lib}/systemd/zram-genera‐
22 tor.conf[.d] (see zram-generator.conf(5) for details);
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24 2. generate systemd.swap(5) units into TARGET_DIR and make swap.target
25 depend on them;
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27 3. ensure the zram module is loaded and create the requested devices.
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31 The generator does nothing if run inside a container (as determined by
32 systemd-detect-virt(8) --container).
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34 Setting the ZRAM_GENERATOR_ROOT environment variable makes the genera‐
35 tor run in test mode, in which case containerisation is ignored and
36 step 3 is skipped.
37 For the ramifications of ZRAM_GENERATOR_ROOT on config handling, see
38 zram-generator.conf(5).
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40 The generated dev-zramN.swap units depend on zram-create@zramN.service,
41 which will:
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43 1. read configuration files from {/etc,/lib}/systemd/zram-genera‐
44 tor.conf[.d] (see zram-generator.conf(5) for details);
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46 2. set the desired compression algorithm, if any; if the current ker‐
47 nel doesn´t understand the specified algorithm, a warning is
48 issued, but execution continues;
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50 3. set the desired blockdev size and format it as swap with sys‐
51 temd-makefs(8).
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55 When the unit is stopped, the zram device is reset, freeing memory and
56 allowing the device to be reused.
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58 zram-generator implements systemd.generator(7).
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61 <https://github.com/systemd/zram-generator/issues>
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64 zram-generator.conf(5), systemd.generator(7), systemd.swap(5)
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66 <https://github.com/systemd/zram-generator>
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68 Linux documentation of zram: <https://kernel.org/doc/html/lat‐
69 est/admin-guide/blockdev/zram.html>
70 and the zram sysfs ABI: <https://kernel.org/doc/Documentation/ABI/test‐
71 ing/sysfs-block-zram>
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75zram-generator 0.2.0 June 2020 ZRAM-GENERATOR(8)