<div dir="ltr"><br><br><div class="gmail_quote">On Mon, Apr 1, 2013 at 7:14 AM, Wolf Halton <span dir="ltr"><<a href="mailto:wolf.halton@gmail.com" target="_blank">wolf.halton@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div>A gotcha on ZFS:<br></div>If it ever fills up a drive array, for instance the backup process starts writing recursively, you can't remove anything, since it uses disk space to write a cache of what you delete. You have to copy the files to a larger array and reformat your stuffed ZFS array. Ask me how I know?<br>
</div></blockquote><div><br>from Oracle Solaris ZFS Administration Guide • August 2010 page 58<br><br>" Out of Space Behavior<br>File system snapshots are inexpensive and easy to create in ZFS. Snapshots are common in most<br>
ZFS environments. For information about ZFS snapshots, see Chapter 7, “Working With<br>Oracle Solaris ZFS Snapshots and Clones.”<br>The presence of snapshots can cause some unexpected behavior when you attempt to free disk<br>
space. Typically, given appropriate permissions, you can remove a file from a full file system,<br>and this action results in more disk space becoming available in the file system.However, if the<br>file to be removed exists in a snapshot of the file system, then no disk space is gained from the<br>
file deletion. The blocks used by the file continue to be referenced from the snapshot.<br>As a result, the file deletion can consume more disk space because a new version of the directory<br>needs to be created to reflect the new state of the namespace. This behavior means that you can<br>
receive an unexpected ENOSPC or EDQUOT error when attempting to remove a file."<br><br>yeah. that looks fun. So snapshots are a double-edged sword.<br> <br><br>The data deduplication is very useful until it's backup time. It looks like the backup will un-deduplicate and use full-size storage less backup compression abilities.<br>
</div></div><br>-- <br>-- <br>James P. Kinney III<br><i><i><i><i><br></i></i></i></i>Every time you stop a school, you will have to build a jail. What you
gain at one end you lose at the other. It's like feeding a dog on his
own tail. It won't fatten the dog.<br>
- Speech 11/23/1900 Mark Twain<br><i><i><i><i><br><a href="http://electjimkinney.org" target="_blank">http://electjimkinney.org</a><br><a href="http://heretothereideas.blogspot.com/" target="_blank">http://heretothereideas.blogspot.com/</a><br>
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