Date: Wed, 29 Nov 2017 00:26:39 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 223955] cpio needs a --block-size= option Message-ID: <bug-223955-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D223955 Bug ID: 223955 Summary: cpio needs a --block-size=3D option Product: Base System Version: 9.1-RELEASE Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: bin Assignee: freebsd-bugs@FreeBSD.org Reporter: rfg@tristatelogic.com I didn't get the memo, so I'm only just now finding out that "cpio -p" can be WAAAAAY slower than "cp" for the same file, at least on my Ubuntu/Linux system. I have some reason to believe that this will = be true if I test it also on FreeBSD. (The issue seems like it will be the same on both systems.) The problem seems to be that the default I/O block size used by cpi= o... left over from ancient times (e.g. 1970's) is 512 bytes. This can be increased somewhat (to 5120 bytes) using the -B option, however in the current era of large media files and multi-terabyte disk drives... many of which themselves have a native hardware block size of 4 KiB... even a block size of 5120 bytes is ludicrously small, and causes a massive performance hit. The Linux people, at least, seems to have recognzied the issue, and have added a --block-size=3D option to their version of cpio. I th= ink it's well past time that FreeBSD followed suit and did likewise. Environment: System: FreeBSD segfault.tristatelogic.com 9.1-RELEASE FreeBSD 9.1-RELEASE = #0 r243825: Tue Dec 4 09:23:10 UTC 2012 root@farrell.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC amd64 How-To-Repeat: Just try copying a large file multi-gigabyte file using "cpio -p" and time the command. Then, using a different file of about the same size, just do the same thing using "cp" and time that also. On Ubuntu, at least, there is a stunning 6.92x speed difference. I know. I measured it. Fix: Sorry. No. I don't have the code patches to implement this suggestion. but I felt that it was worth making the suggestion anyway. --=20 You are receiving this mail because: You are the assignee for the bug.=
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