Date: Fri, 7 Feb 2003 12:40:22 -0800 (PST) From: "Simson L. Garfinkel" <simsong@lcs.mit.edu> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/48062: mount -o snapshot doesn't work on +100GB disks Message-ID: <200302072040.h17KeMW1012967@freefall.freebsd.org>
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The following reply was made to PR kern/48062; it has been noted by GNATS. From: "Simson L. Garfinkel" <simsong@lcs.mit.edu> To: Garrett Wollman <wollman@lcs.mit.edu> Cc: "Simson L. Garfinkel" <simsong@nitroba.com>, FreeBSD-gnats-submit@FreeBSD.ORG Subject: Re: kern/48062: mount -o snapshot doesn't work on +100GB disks Date: Fri, 7 Feb 2003 15:33:46 -0500 Thank you. The process never finished. If you are in NE43, I can leave it running on my desktop here. The snapshot feature is very useful for me, but I need to be able to do it on /usr. I have to catch a train in a few minutes, but I can do this on Monday, if you wish. On Friday, February 7, 2003, at 03:30 PM, Garrett Wollman wrote: > <<On Fri, 7 Feb 2003 14:47:30 -0500 (EST), "Simson L. Garfinkel" > <simsong@nitroba.com> said: > >> Greetings. I have successfully used mount -o snapshot on volumes >> less than 30Gb, but when I use it on my 150GB volume, the command >> hangs >> and slowly every other process hangs as well. This behavior is >> observed on both a RC2 system and on a 5.0-RELEASE system. > > Well, at least on a 73-gig disk that was convenient to hand, I can't > replicate this problem on a quiet system. Creating the snapshot did > take some tens of seconds, and it took about ten seconds to delete it > again. The process of creating a snapshot requires that all > filesystem activity be brought to a temporary halt, so it is not > surprising that creating a snapshot on /usr would eventually hang > most other processes until it is completed. Please check the wait > channels (by starting something like `top' in another window/VT or by > using the `ps' command from DDB) to see what states various processes > are in. > > FYI, the exact results for my experiment are: > > create 39.92 real 0.00 user 1.20 sys > remove 8.72 real 0.00 user 0.31 sys > > The resulting snapshot contained 42221568 bytes of metadata. > (Keeping in mind that this filesystem is empty but for the root > directory, the directory containing the snapshot, and the snapshot > itself.) > > -GAWollman To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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