Reply

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

davidk1952
Tutor

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 add capacity to avoid performance degradation.

 

I curently have it filled with 4ea 4TB Red drives which give me a total of 10.9TB under raid 5.  I have 2.96 TB left and I"m getting the above notice, first I started getting the 30% notice and now the 20% notice.  I guess I am wondering I assumed the difference from 16TB total drive to the 10.9TB  the overhead is taken up i the difference, but why am I getting  the notice with almost 3 TB left ?  All my drives look healthy  ( I have just got the notice of the Update firmware but until I get this notice squared away I don't want to change the Firmware..

 

Hopefully this is an easy fix. 

 

I have 2 of thes Nas set up the same way with the same drives so I guess at somepoint I'll have to deal with the 2nd on.  

 

I'm not sure what else to add it seems to be a fairly well discussed subject. 

 

Dave

Model: RN204|ReadyNAS204 4-Bay
Message 1 of 14

Accepted Solutions
StephenB
Guru

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade


@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.

View solution in original post

Message 14 of 14

All Replies
rn_enthusiast
Virtuoso

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

Hi @davidk1952 

 

This warning does seem to come too early in your case. With a volume of 10.9 TB you shouldn't see this warning till about 2.18 TB left. I wonder if quotas are causing some oddities here. I wouldn't mind taking a look at your logs if you want.

 

You can download the NAS logs into a zip file.
- Go to the ReadyNAS web admin page and navigate to "System" > "Logs".
- Here you will see an option to "Download Logs" on the right-hand side.
- This will download a zip file containing the logs.

 

Once downloaded, then upload to Google drive, Dropbox or similar and give me a link to download them. PM me this link, don't share it publicly here on the forums.


Cheers

Former Netgear employee. Views and opinions are my own.
Message 2 of 14
davidk1952
Tutor

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

Perhaps I was not clean...  the ballance left on the NAS is.2.26TB out of 10.9TB so, I am getting pretty close to what you said.   So what happens when the NAS starts to get that full... I figure the difference from my Original 16TB to 10.9 is the overhead and backup.   If you would still like me to send you the log but I'm not sure if it's just telling me I"m getting close... but how many TB can I actually have on the drive when you would consider it full.  

 

I have not set up my email allert as yet, that's another story 🙂 but I keep a pretty good eye on the allerts. 


@rn_enthusiast wrote:

Hi @davidk1952 

 

This warning does seem to come too early in your case. With a volume of 10.9 TB you shouldn't see this warning till about 2.18 TB left. I wonder if quotas are causing some oddities here. I wouldn't mind taking a look at your logs if you want.

 

You can download the NAS logs into a zip file.
- Go to the ReadyNAS web admin page and navigate to "System" > "Logs".
- Here you will see an option to "Download Logs" on the right-hand side.
- This will download a zip file containing the logs.

 

Once downloaded, then upload to Google drive, Dropbox or similar and give me a link to download them. PM me this link, don't share it publicly here on the forums.


Cheers


 

Message 3 of 14
davidk1952
Tutor

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

Just sent a PM with the drop box link

Message 4 of 14
davidk1952
Tutor

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

Just sent you the dropbox link to the log.

Message 5 of 14
rn_enthusiast
Virtuoso

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

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

Former Netgear employee. Views and opinions are my own.
Message 6 of 14
davidk1952
Tutor

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

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

Message 7 of 14
rn_enthusiast
Virtuoso

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

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:

https://kb.netgear.com/23135/How-do-I-vertically-expand-an-X-RAID-2-volume-on-my-ReadyNAS-OS-6-stora... 

 

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

Former Netgear employee. Views and opinions are my own.
Message 8 of 14
davidk1952
Tutor

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

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

Message 9 of 14
rn_enthusiast
Virtuoso

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

Yea personally I wouldn't run with quotas enabled but it is a personal choice but at least you know now that the space you see taken is correct and not influenced by wonky quotas 🙂

 

With raid 5 you need to add at least two disks for the expansion to work. Again, add one disk and let is sync in, then the next one, etc. Never pull two disks at the same time! Always ensure you have an up-to-date back before staring - just in case.

 

There is a HDD compatibility list here: https://kb.netgear.com/20641/ReadyNAS-Hard-Disk-Compatibility-List 

 

Finding a HDD in that list would be a good call. Be careful not to pick a drive that uses SMR (Shingled magnetic recording). Those are bad for NAS drives and I would also avoid any "green" drives. Besides that, pick what you like or see a good deal on.

 

I use the RN4xx series at home. The RN424 is a very good unit and Intel based. Can be used for Plex too without issues but I would have picked the RN426 if I would do it over again because that unit has a stronger CPU and upgradeable RAM. The RAM on the RN422 and RN424 are soldered to the motherboard. They are going to be a little more pricey but worth the cost in my opinion and they are a good enthusiast level NAS. Anything above that (RN5xx and RN6xx series) are awesome but also much higher price point and likely overkill for home use.

https://www.netgear.co.uk/business/products/storage/readynas/readynas-desktop.aspx#tab-models 

 

One thing we have noticed recently is that the ReadyNAS line seems to be on low stock many places. There is nothing official from Netgear on this though but they haven't updated with new models in 3+ years so they might be fading out the ReadyNAS line, who knows! I wouldn't necessarily let that deter you as you will still get the warranty, etc. when buying the unit. The RN4xx, 5xx and 6xx line also comes with 5 years warranty as opposed to the ARM based series 3 years. If I were to look else where for a NAS I would look at Synology and QNAP. I am very interested in the new QuTS Hero line that has just come out this year as those NAS units use the ZFS filesystem (and they are expensive) but that just because I am a nerd when it comes to these things 🙂

 

I worked in Netgear for around 5 years and left in early 2018 but I like Netgear's products and I re-visit the forums from time to time to try and help people out. I had a change of email and stuff so I had to create a new forums profile. This is my old profile, in case you were wondering:

https://community.netgear.com/t5/user/viewprofilepage/user-id/336529 

 

 

Cheers

Former Netgear employee. Views and opinions are my own.
Message 10 of 14
davidk1952
Tutor

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

So,  I have Quota's turned off and not going to worry about it, thanks for the tip.  In my first Iomega Nas units shipped with Seagate Baracuda 7200 drives and honestly they worked pretty good for quite some time... I switched to WD RED 5400 drives as I replaced the Seagates and increased capacity and I guess I've been sticking with the Red drives since... each of my RN204 have 4e 4TB Red drives.   It has just worked and it's easy to find them. Now the SMR issue has just started to show up in the last 6months of discuddions, some say the Red are and some say they are not...but going forward I'll be sure to stay away from any that are...   As drives got cheaper and going to 1 platter with high compression I can only imagine the nightmare they could be.  I will take a look at the compatitbility list before I do anything...  Too bad I missed the sale on 8TB 5400 drives before christmas, I should have just picked up 4 of them 🙂  

 

I will checkout the NAS systems you mentioned, I"ve kind of kept my eye the market, who knows there might be a sale before New Years.... (it's my wifes birthday, I"ll buy it and tell it is for her for her birthday since she likes so many movies)... don't think it will work, but I"ll try.

 

My background as I had said started back in the day of the IBM, HP DEC and other computers that stood 6' tall and today would have less power than your cell phone, technlogy for the end user has reallly stepped up and I had the oppertunity at being on the front end of it.. (see your PM from me)  depending on your age you may or may not remeber it...  

 

When I was working the companines I was involved with did alot of international business so I got to travel quite a bit, I remember the days of the Hanover Fair, staning in a booth for 10 days each year and spending time with my wife traveling and visiting the different countries .. 

 

Anyway  thanks for the help  I really appreciate it..

 

Dave

 

 

Message 11 of 14
Sandshark
Sensei

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade


@davidk1952 wrote:

Now the SMR issue has just started to show up in the last 6months of discuddions, some say the Red are and some say they are not...but going forward I'll be sure to stay away from any that are...   

 


Currently shipping "Red" drives <8TB are SMR.  After being called out on the issue, WD introduced the "Red Plus" line, which is still 5400RPM but also CMR.  "Red Pro" are still CMR, and are 7200RPM.

Message 12 of 14
davidk1952
Tutor

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade

So  go Red Pro if I'm going to change... Good to know... They were just on sale, darn!

Message 13 of 14
StephenB
Guru

Re: Alert Less than 20% of volume data's capacity is free. Performance on volume data will degrade


@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.

Message 14 of 14
Top Contributors
Discussion stats
  • 13 replies
  • 1675 views
  • 0 kudos
  • 4 in conversation
Announcements