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I'm using nsclient++ to check our windows server and so far so good. However, for servers with large disks, the 10% threshold isn't cutting it. Ten percent is really 18G free and that's still a lot of available space. Is there a way to specify a hard value say "6G" instead of 10%?

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up vote 1 down vote accepted

You can set a fixed size in nsclient++ CheckDriveSize command, see . That said, NTFS suffers from performance problems on partitions that are greater than 80% full so just keep that in mind.

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You can always change the percentage. Some of our larger systems are tuned to alert at, e.g., 5% or 2%, depending on (a) total available space and (b) usage patterns.

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As larsks said we also just adjust the percentage to fit the needs of the server. Although it's worth considering that if you're down to 10% on a drive, that means you've got it 90% full - you still might want to consider cleaning it or adding more storage. While 18 gigs free is a lot - you still may want to have ample time and warning to start considering what, if any, actions you may need to take soon.

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Just keep in mind that filesystems do start to have performance issues as they fill up. XFS is probably the most notorious for this. So while 20% may seem high it is possible for it to cause some issues.

Also most ext* filesystems default to 5% reserved space. So it's possible to run into out of space issues before you actually fill up the drives.

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In 0.3.9 (not yet release BTW) "check_mk's magick" disk modifiers will be added so it can rescale the percentages between large and small drives (so you can use 80% but for very large drives this will be increased to a larger value).

// Michael Medin

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