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Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade
Firmware 6.10.3 I am seeing this allert Less than 20% of volume data's capacity is free. Performance on volume data will degrade if additional capacity is consumed. NETGEAR recommends that you ad...
davidk1952 wrote:
I assumed the difference from 16TB total drive to the 10.9TB the overhead is taken up i the difference,
Just to clarify the volume size. With XRAID/RAID-5 the volume capacity for 4x4TB is 12 TB. The other 4 TB are used for RAID parity blocks (which is what the system uses to rebuild a disk when it is replaced).
But the NAS reports sizes in TiB (1024*1024*1024*1024 bytes), not TB (1000*1000*1000*1000 TB). 12 TB is the same as 10.9 TiB.
2.26/10.9 is about 20% (slighty more, but there could be some accounted for space).
The warnings are quite conservative. Generally I expand my volume when free space drops to about 15%, and I haven't had any issues with stability.
FWIW, I do leave quotas on, so I can see the space used by every share.
Just sent you the dropbox link to the log.
Hi davidk1952
The disks and raid are healthy, which is good.
I want to point out that the NAS uses Tebibiyes not Terabytes (it's a Linux thing). So, your actual space is 10.9 Tib = 11.98468 TB. This makes sense given you have 4 x 4TB drives in a raid 5 config - i.e. one drive goes to redundancy, leaving you with ~12TB usable space (10.9 TiB).
The NAS makes a raid with a software called mdadm (Multidisk administration) and then it presents the raid as one whole device to the filesystem layer. Therefore, the filesystem is not aware of the underlying raid, in that sense. It also means that the raw 16TB has no place in the space usage calculations. The filesystem sees a device presented that is 10.9 TiB (~12TB) and it created a volume on that device, so from the filesystem perspective that is all there is to it. You have a volume of 10.9 TiB and it looks at how much is occupied by data out of the those 10.9 TiB and there is your calculation.
Looking at the filesystem stats, I can see that you indeed have a volume of 10.9 TiB and you have used exactly 8.64TiB. That is 79.26% space used. This means the warning you are getting is triggered correctly. The filesystem sees that 80% of the space is used and the NAS triggers a warning.
I will mention one thing here. The (BTRFS) filesystem quotas are looking wonky as we have seen before. This can sometimes lead to incorrect capacity calculations by the filesystem. I see references to subvolumes that don't exist and also see nonsense like below where it reports some fictitious subvolumes (shares/snapshots) are 16 Exbibyte in size:
=== qgroup /data ===
qgroupid rfer excl max_rfer
-------- ---- ---- --------
0/262 16.00EiB 16.00EiB none
0/270 16.00EiB 16.00EiB none
0/271 16.00EiB 16.00EiB none
0/1180 16.00EiB 16.00EiB none
0/1181 16.00EiB 16.00EiB none
0/1186 16.00EiB 16.00EiB none
0/1188 16.00EiB 16.00EiB none
0/1192 16.00EiB 16.00EiB none
0/1193 16.00EiB 16.00EiB none
0/4716 16.00EiB 16.00EiB none
0/4717 16.00EiB 16.00EiB none
It is obviously nonsense and simply a bi-product of BTRFS quotas being "finicky" and sometimes calculates incorrectly. We have seen this several times before. You read more about it here
We also had a recent discussion about this topic in this thread
I would advise that you disable quotas and reboot your NAS. See if you get some "more space". You can re-enable them afterwards but I would suggest to keep them off. The only thing they provide are snapshot and share space consumption calculations for you to see - neither which are essentials.
To disable Quotas, go to admin web page and navigate to: "System" > "Volumes" > Click the cog-wheel next to your raid Volume > select "Settings". Once in Setting, select "Summary" on the left hand side. Here you Un-tick the box that says: "Quota" > Click "Apply" at the bottom. Afterwards, give the NAS a reboot.
Hope this helped. Cheers
Well, thanks for all the information and I will take our suggestion on Quotas and see what I end up with...
that is interestiong about the TBvs TiB I've been in the computer business since the early 80's and that's the first time I've heard of that, but I don't do anyting with Lynix directly but makes sense.
Like I said, I have 2 of these units, I really like them and they are easy to work with.
I notice there is a firmware update noted for the RN204 firmware should I do the firmware update first then deal with the Quota? or do the Quota, reboot and then up date?
Finally.. if I wanted to up the drive size to 8TB drives would you suggest backing all the files to an external drive and then do the upgrade vs trying to replace and rebuild the NAS?
Or what new NAS would you suggest I"m always looking to add to my server room :-)
Dave
Yea, Linux tend to default to using Tebibytes (TiB) rather than Terabyes (TB). I am not exactly sure why but I assume it stems back from the early days of computing and it just stuck. But it does not really matter as it is just a unit of measurement and you will still have the same physical space/volume to work with, whether it is reported in TiB or TB :)
In the other thread that I linked to, the user got his quota abnormalities solved by simply doing the upgrade. I see no downside to proceeding with that upgrade. Keep in mind, the upgrade won't fix any quota issues, they simply got temporarily "solved" for that user by "refreshing" the quota module (the restart did it more than anything, likely). But same scenario can happen again as quotas aren't build or provided by Netgear but rather a feature in the BTRFS filesystem - a feature that still to this day is buggy at times. You can use it if you want, it is your own call.
You can add larger disks if you so wish. Just add them one at a time and leave the raid to sync in-between. You can read about vertical expansion here:
I am gonna say something potentially controversial. In my opinion, and this is my opinion with no hard facts behind it, the ReadyNAS ARM based units (like yours) tend to see more filesystem corruption cases than the stronger Intel based units. This is especially true on large volumes (+10 TB) as you have. I don't know particular details behind that but I suspect the ARM CPU just isn't properly capable of handling large volumes and something goes haywire at some point. Again, this isn't a documented or advertised limit and I am sure many ReadyNAS ARM units run large volumes out there in the world - it is just my experience and you can take that for what you want.
Before any expansion happens though, always ensure you have a backup of your data. It should be a straight forward procedure but better to be safe than sorry!
Cheers
Good Morning, So, I have gone in and selected and clicked Quota off on both of my RN 204 units re booted, then did the firmware update and rebooted and everything went smooth on both units. The amount of disc space did not change it is still as it was before the updates and reboot My one unit still shows 2.28TB of 10.9 left, and everything seems to be working property. My concern was of course the notice that the system performance would drop and that is somehting I do not want :-)
Thanks for the link to the capacity upgrade, since I am in Raid 5 it says I need to replace 2 drives at a time, is that correct and is there any suggetion on which 2 drives to start with when upgrading? My guess would be go to 8TB drives if I do the upgrade on this sytem.
Saying that, thanks for the info on the ARM vs Intel I will do a little more reading, Is there a specific unit that seems more reliable than others? I am guessing I'd stay with the 4 drive systems (although I am seeing 5 drive systems on line) I use the NAS mainly for storage feeding my PLex server, it is all used only in our home and usually only one TV at a time although over the years I have collected alot of content.. have ripped and put all of my DVD and CD collection on line and ripped all the CDs to FLAC losless and it has worked perfectly and made finding and playing my music much easier. Our network is a 1GB network and is all Cat 6 cables with pretty much everyting either direct home run or through a variety of GB switches.
I guess since I am thinking of getting higher capacity drives it may well look at adding another NAS, like I mentioned I will look at the intel based systems and if you have any suggestions on "Reliable" manufactuers I'd appreciate it.
From your signature, it says you are not currently a Netgear employee, so you do this for fun now (support) for us on the forum, I'd say, you are much higher level than alot of folks I see on support forums.... and I"m glad your here.
If you would like to answer any of my questions via PM that would be fine, I understand this is a Netgear forum and other manufacture discussions may not be allowed... so a PM may work better :-)
Thanks again for your help and I look forward to your respones.
Dave
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