From: "René Berber" <rene.berber@gmail.com>
To: cygwin@cygwin.com
Subject: Re: Renaming (with 'mv') very large files is SLOW
Date: Mon, 31 Jan 2022 09:13:59 -0600 [thread overview]
Message-ID: <d3c5507d-4425-94d6-c985-30c7093d626b@gmail.com> (raw)
In-Reply-To: <c1e4529a-d119-1662-6eeb-2d42950802c7@cs.umass.edu>
On 1/31/2022 8:59 AM, Eliot Moss wrote:
> On 1/31/2022 9:52 AM, cygwin@kosowsky.org wrote:
>> I tried renaming some very large files (20-40 GB) using: mv
>> <oldname> <newname> without changing the directory of course.
>>
>> The process took about 10-20 minutes with Task Manager showing
>> disk activity of 100+ MB/s.
>>
>> Is there something about such large 'renaming' that actually
>> results in the file being really moved (aka copied) rather than
>> just renamed?
>
> The two places are probably on different volumes (loosely, different
> disks). That requires a physical move, even under Linux. Your
> volumes seem a bit slow to access - is one perhaps across a slow
> network? The rates you cite suggest movement of 50Mb/s (50Mb read +
> 50Mb write = 100Mb overall). For 40 Gb that should take 40Gb / 50Mb
> = about 820 secs = a little under 14 mins.
>
> (When I say your volumes are slow, I speak from the luxury of having
> a 2Tb solid state drive! Actually, those speeds may be reasonable
> depending on the nature of your system.)
>
> If the two locations are on different drives, there's no real
> avoiding this.
Nope, I've also complained about this (long ago), if the two locations
are the same remote drive... Cygwin moves the entire file over the network.
I ended up writing my own Samba mv command.
--
R. Berber
next prev parent reply other threads:[~2022-01-31 15:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-31 14:52 cygwin
2022-01-31 14:59 ` Eliot Moss
2022-01-31 15:13 ` René Berber [this message]
2022-01-31 15:20 ` cygwin
2022-01-31 15:51 ` [EXTERNAL] " Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2022-01-31 15:17 ` cygwin
2022-01-31 21:36 ` Adam Dinwoodie
2022-02-02 17:09 ` L A Walsh
2022-02-01 8:47 ` Andrey Repin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d3c5507d-4425-94d6-c985-30c7093d626b@gmail.com \
--to=rene.berber@gmail.com \
--cc=cygwin@cygwin.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).