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On Tue, 11 Oct 2011 22:56:31 +0200 |
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"Stefan G. Weichinger" <lists@×××××.at> wrote: |
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> |
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> As mentioned in the systemd-posting I migrated back to an SSD today |
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> (on my main rig, the thinkpad uses an SSD happily for a long time |
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> now). |
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> |
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> A feature in a local magazine updated my knowledge of how to make use |
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> of the TRIM-command. |
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> |
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> It told me not to use the mount-option "discard" anymore, but run |
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> fstrim 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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Yes, you misunderstand how fstrim works. It's not up to you to say what |
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it does exactly, it's up to the drive firmware and possibly the kernel. |
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It's actually fully described in the man page right there in the part |
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for option -v :-) |
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A convenient on-line copy of the man page: |
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http://www.vdmeulen.net/cgi-bin/man/man2html?fstrim+8 |
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-- |
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Alan McKinnnon |
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alan.mckinnon@×××××.com |
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