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On Tue, 11 Oct 2011 22:56:31 +0200, Stefan G. Weichinger wrote: |
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> |
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> As mentioned in the systemd-posting I migrated back to an SSD today (on |
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> my main rig, the thinkpad uses an SSD happily for a long time now). |
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> |
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> A feature in a local magazine updated my knowledge of how to make use of |
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> the TRIM-command. |
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> |
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> It told me not to use the mount-option "discard" anymore, but run fstrim |
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> on the mountpoint frequently. |
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> |
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> OK, I learn ;-) |
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> |
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> But, AFAI understand, after trimming sectors/bytes on the |
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> filesystem/partition, they should be trimmed. I expect X bytes to be |
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> trimmed at first and if I repeat the command, I expect 0 (or something |
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> pretty low) bytes to be trimmed then, ok? |
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> |
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> This is what I wonder about: |
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> |
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> ~ # fstrim -v / |
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> /: 6195433472 bytes were trimmed |
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> ~ # fstrim -v / |
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> /: 6195433472 bytes were trimmed |
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> ~ # fstrim -v / |
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> /: 6195433472 bytes were trimmed |
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> |
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> |
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> I tested it with "discard" on and off. |
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> |
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> / is ext4, yes, and on an SSD, yup. |
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> |
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> Do I misunderstand things here? |
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> |
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> Thanks, Stefan |
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> |
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This seems in accordance with the fstrim man page: |
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"fstrim will report the same potential discard bytes each time, but only |
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sectors which had been written to between the discards would actually be |
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discarded by the storage device." |
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What is the benefit of running fstrim manually over mounting with discard? |
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-- |
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Neil Bothwick |
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