From owner-freebsd-bugs Fri Feb 7 12:40:21 2003 Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4108C37B401 for ; Fri, 7 Feb 2003 12:40:20 -0800 (PST) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id DFC5F43F3F for ; Fri, 7 Feb 2003 12:40:19 -0800 (PST) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.12.6/8.12.6) with ESMTP id h17KeJNS012928 for ; Fri, 7 Feb 2003 12:40:19 -0800 (PST) (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.12.6/8.12.6/Submit) id h17KeJKw012927; Fri, 7 Feb 2003 12:40:19 -0800 (PST) Date: Fri, 7 Feb 2003 12:40:19 -0800 (PST) Message-Id: <200302072040.h17KeJKw012927@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org Cc: From: Garrett Wollman Subject: kern/48062: mount -o snapshot doesn't work on +100GB disks Reply-To: Garrett Wollman Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org The following reply was made to PR kern/48062; it has been noted by GNATS. From: Garrett Wollman To: "Simson L. Garfinkel" Cc: FreeBSD-gnats-submit@FreeBSD.ORG Subject: kern/48062: mount -o snapshot doesn't work on +100GB disks Date: Fri, 7 Feb 2003 15:30:07 -0500 (EST) < 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