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Ask Slashdot: Smarter Disk Space Monitoring In the Age of Cheap Storage?
relliker writes In the olden days, when monitoring a file system of a few 100 MB, we would be alerted when it topped 90% or more, with 95% a lot of times considered quite critical. Today, however, with a lot of file systems in the Terabyte range, a 90-95% full file system can still have a considerable amount of free space but we still mostly get bugged by the same alerts as in the days of yore when there really isn't a cause for immediate concern. Apart from increasing thresholds and/or starting to monitor actual free space left instead of a percentage, should it be time for monitoring systems to become a bit more intelligent by taking space usage trends and heuristics into account too and only warn about critical usage when projected thresholds are exceeded? I'd like my system to warn me with something like, 'Hey!, you'll be running out of space in a couple of months if you go on like this!' Or is this already the norm and I'm still living in a digital cave? What do you use, on what operating system?
Isn't smart enough to track trends, but it does do graphs so you can easily see where your headed and how fast.
Well, ext4 strives to scatter files around disk to avoid fragmentation. Once the disk begins to approach full, it has to use even smaller and smaller holes to place data into, which causes some fragmentation.
I install the shareware version of Hard Drive Sentinel on all my Windows systems. It not only will warn you about hard drive usage (%); it will also warn you about errors on the drive -- and in my case I was able to predict that two drives were going to fail (saving data) before they actually failed.
Their support has been very responsive and courteous, their product can work through (see drives behind) most RAID controllers.
And no, I don't have any affiliation with HDS.
It's a configuration option when you newfs a file system. Man newfs or mkfs.
[John]
Shit better not happen!
Exactly. The question is strange (and the attitude of the poster is odd too... 20 years ago is "days of yore", and "olden days"?) Methinks dusting off the word "whippersnapper" might be appropriate here.
Oddly enough, a similar question fell through a wormhole in the space time continuum from Usenet, circa 1994. "Now that we have massive HDs of 100s of megabytes, and not the dinky little ones of several megabytes from the Reagan era, do we still have to worry about having 95% usage alarms?"
The truth being, if you got to 95% usage somehow, what makes you think that you're not going to get to 100% sometime soon? Maybe you won't, but you can't know unless you understand how and why your usage increases. That's not going to be solved by a magic algorithm alone, it involves understanding where your data comes from, and who or what is adding to it. This isn't new. The heuristics and usage question, and estimating when action needs to be taken is just as relevant now as it was 20 years ago.
AccountKiller
We switched to Check_MK for monitoring. It's basically a collection of software that sits on top of Nagios.
The default disk monitoring allows alerting based on trends (full in 24hours, etc.) or thresholds based on a "magic factor." Basically it scales the thresholds so that larger disks alert at a higher percentage, adjustable in quite a few different ways to suit your tastes.