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Groups > linux.debian.user > #235255
| From | <tomas@tuxteam.de> |
|---|---|
| Newsgroups | linux.debian.user |
| Subject | Re: OT: minimum bs for dd? |
| Date | 2021-05-17 10:10 +0200 |
| Message-ID | <CfGu5-4sx-5@gated-at.bofh.it> (permalink) |
| References | (5 earlier) <CfwEq-6M4-5@gated-at.bofh.it> <CfxAx-7ko-21@gated-at.bofh.it> <CfEBX-3mC-1@gated-at.bofh.it> <CfF50-3vP-7@gated-at.bofh.it> <CfFRn-40O-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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On Mon, May 17, 2021 at 10:29:06AM +0300, Andrei POPESCU wrote:
> On Lu, 17 mai 21, 08:32:28, tomas@tuxteam.de wrote:
> > On Mon, May 17, 2021 at 08:59:43AM +0300, Andrei POPESCU wrote:
> >
> > [...]
> >
> > > I'll raise you 'cp':
> > >
> > > cp foo.iso /dev/sdb
> > >
> > >
> > > which is both fast and short to type (apparently it's smart about using
> > > the correct block size).
> >
> > I'll be sure to try that some day :)
> >
> > > Unfortunately it's missing dd's equivalent of status=progress.
> >
> > and oflags=sync.
>
> Hmm, would you (or anyone else) know what is the difference between
> oflags=sync and conv=fsync?
Let me put the docs next to each other (this is from the info page,
which sometimes is more complete than the man page):
* conv=fsync:
‘conv=CONVERSION[,CONVERSION]...’
Convert the file as specified by the CONVERSION argument(s). (No
spaces around any comma(s).)
[...]
The following “conversions” are really file flags and don’t affect
internal processing:
[...]
‘fsync’
Synchronize output data and metadata just before finishing.
This forces a physical write of output data and metadata.
* oflag=sync:
‘oflag=FLAG[,FLAG]...’
Access the output file using the flags specified by the FLAG
argument(s). (No spaces around any comma(s).)
[...]
‘dsync’
Use synchronized I/O for data. For the output file, this
forces a physical write of output data on each write. For the
input file, this flag can matter when reading from a remote
file that has been written to synchronously by some other
process. Metadata (e.g., last-access and last-modified time)
is not necessarily synchronized.
‘sync’
Use synchronized I/O for both data and metadata.
I'd say "conv=fsync" does a sync at the end of the whole thing, while
"oflag=sync" open(2)s the file with O_SYNC (likewise "oflag=dsync"
translates to an open(2) with O_DSYNC), so the sync happens after each
block write. That's what I want, since it gives me much more predictability
as to when I can plop out my usb stick :)
Cheers
- t
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OT: minimum bs for dd? Bob Bernstein <poobah@ruptured-duck.com> - 2021-05-15 22:30 +0200
Re: OT: minimum bs for dd? The Wanderer <wanderer@fastmail.fm> - 2021-05-15 22:40 +0200
Re: OT: minimum bs for dd? IL Ka <kazakevichilya@gmail.com> - 2021-05-15 22:40 +0200
Re: OT: minimum bs for dd? Bob Bernstein <bob@fanatick.org> - 2021-05-16 09:40 +0200
Re: OT: minimum bs for dd? Michael Stone <mstone@debian.org> - 2021-05-16 19:50 +0200
Re: OT: minimum bs for dd? Richard Owlett <rowlett@cloud85.net> - 2021-05-16 20:40 +0200
Re: OT: minimum bs for dd? Stefan Monnier <monnier@iro.umontreal.ca> - 2021-05-17 00:40 +0200
Re: OT: minimum bs for dd? The Wanderer <wanderer@fastmail.fm> - 2021-05-17 00:50 +0200
Re: OT: minimum bs for dd? "Thomas Schmitt" <scdbackup@gmx.net> - 2021-05-17 09:00 +0200
Re: OT: minimum bs for dd? The Wanderer <wanderer@fastmail.fm> - 2021-05-17 12:30 +0200
Re: OT: minimum bs for dd? Greg Wooledge <greg@wooledge.org> - 2021-05-17 13:20 +0200
Re: OT: minimum bs for dd? Andrei POPESCU <andreimpopescu@gmail.com> - 2021-05-17 08:10 +0200
Re: OT: minimum bs for dd? <tomas@tuxteam.de> - 2021-05-17 08:40 +0200
Re: OT: minimum bs for dd? Andrei POPESCU <andreimpopescu@gmail.com> - 2021-05-17 09:30 +0200
Re: OT: minimum bs for dd? David <bouncingcats@gmail.com> - 2021-05-17 10:00 +0200
Re: OT: minimum bs for dd? Andrei POPESCU <andreimpopescu@gmail.com> - 2021-05-17 14:10 +0200
Re: OT: minimum bs for dd? <tomas@tuxteam.de> - 2021-05-17 10:10 +0200
Re: OT: minimum bs for dd? Andrei POPESCU <andreimpopescu@gmail.com> - 2021-05-17 14:30 +0200
Re: OT: minimum bs for dd? <tomas@tuxteam.de> - 2021-05-17 15:00 +0200
info pages WHERE? -- was [Re: OT: minimum bs for dd?] Richard Owlett <rowlett@cloud85.net> - 2021-05-17 15:00 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] <tomas@tuxteam.de> - 2021-05-17 15:10 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] Richard Owlett <rowlett@cloud85.net> - 2021-05-17 15:20 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] IL Ka <kazakevichilya@gmail.com> - 2021-05-17 15:30 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] Richard Owlett <rowlett@cloud85.net> - 2021-05-17 16:00 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] Greg Wooledge <greg@wooledge.org> - 2021-05-17 15:40 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] "Thomas Schmitt" <scdbackup@gmx.net> - 2021-05-17 16:10 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] Greg Wooledge <greg@wooledge.org> - 2021-05-17 17:10 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] "Thomas Schmitt" <scdbackup@gmx.net> - 2021-05-17 18:00 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] Brian <ad44@cityscape.co.uk> - 2021-05-17 20:30 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] Greg Wooledge <greg@wooledge.org> - 2021-05-17 20:50 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] Brian <ad44@cityscape.co.uk> - 2021-05-17 21:00 +0200
Re: info pages WHERE? -- was [Re: OT: minimum bs for dd?] <tomas@tuxteam.de> - 2021-05-17 16:10 +0200
Re: OT: minimum bs for dd? Brian <ad44@cityscape.co.uk> - 2021-05-17 16:20 +0200
Re: OT: minimum bs for dd? <tomas@tuxteam.de> - 2021-05-17 08:40 +0200
Re: OT: minimum bs for dd? Richard Hector <richard@walnut.gen.nz> - 2021-05-17 13:40 +0200
Re: OT: minimum bs for dd? Michael Stone <mstone@debian.org> - 2021-05-16 20:50 +0200
Re: OT: minimum bs for dd? "Andrew M.A. Cater" <amacater@einval.com> - 2021-05-16 23:40 +0200
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