From mboxrd@z Thu Jan 1 00:00:00 1970 To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu> Subject: Re: [9fans] Clearing venti arena during install In-reply-to: Your message of "Sun, 26 Mar 2006 19:09:15 EST." From: bakul+plan9@bitblocks.com Date: Sun, 26 Mar 2006 16:23:55 -0800 Message-Id: <20060327002355.F4015294E8@mail.bitblocks.com> Topicbox-Message-UUID: 22336908-ead1-11e9-9d60-3106f5b1d025 > > If fossil+venti is chosen during installation, the entire > > venti arena partition is cleared. Is there a way to avoid > > clearing all of the arena space? Since in a sense it is an > > append only log, and the purpose for clearing it is, > > presumably, to allow recreating the index, may be a shortcut > > exists? Doing so will save a lot of time and space > > particularly on a qemu VM. In qemu one can use a sparse file > > or a qcow format file which allocates space only for data > > actually written. Writing even zeroes can eat up space. > > Any sparse file worth its salt would catch the case > where you write zeros to a hole and not do anything. Creating a hole is as easy as seeking beyond the end of a file and scribbling something but maintaining its holeyness by checking every write for a block of zeroes is quite expensive. > That said, I'd rather leave the zeroing in for now. > The new venti, which I am testing on Plan 9 right now, > does not require the zeroing. This is a much better solution -- I didn't realize this was imminent. Thanks!