pmfsrr mode
Hello, Long time lurker, first time poster, hope I get things right. I have an AuFS mount that is 21TB in size. I’m trying to use AuFS in a way that will ensure my disks (branches) do not fill up and result in out of space issues (preferably without using create=mfs). There are currently 7 disks, and I’m attempting to use the pmfsrr mode without much success. Here is a list of my disks: /dev/sde1 3.6T 3.4T 51G 99% /media/disks/WD-WCC4E5AFUJZK /dev/sdf1 2.7T 2.6T 36G 99% /media/disks/WD-WMC4N0765691 /dev/sdg1 1.8T 1.8T 35G 99% /media/disks/WD-WMAY00153458 /dev/sdh1 1.8T 528G 1.2T 31% /media/disks/WD-WMAZA4509546 /dev/sdi1 2.7T 2.6T 32G 99% /media/disks/WD-WMC4N0751110 /dev/sdj1 2.7T 2.6T 34G 99% /media/disks/WD-WMC4N0855507 /dev/sdk1 2.7T 2.6T 37G 99% /media/disks/WD-WCC1T1479153 /dev/sdl1 2.7T 2.6T 35G 99% /media/disks/SG-W1F1Q1J4 Here is my mount command (I’m running the latest build): mount -t aufs -o br:/media/disks/WD-WMC4N0765691=rw:/media/disks/WD-WMAY00153458=rw:/media/di sks/WD-WCC4E5AFUJZK=rw:/media/disks/SG-W1F1Q1J4=rw:/media/disks/WD-WCC1T1479 153=rw:/media/disks/WD-WMC4N0751110=rw:/media/disks/WD-WMC4N0855507=rw:/medi a/disks/WD-WMAZA4509546=rw-osum,create=pmfsrr:53687091200,udba=notifynone /mnt/media Now, from my understanding of the manual, the way I’m mounting with pmfsrr, I am setting a [low] value of 50GB. Again, according to my understanding, if all branches are below the “low” value, it will just round robin to one of the other branches that has the most space (from man: If there are less than ’low’ bytes available on all branches where the parent dir exists, aufs selects the one which has the most free space regardless the parent dir). The way I’m interpreting that is if “parentdir” exists on 2 of the branches, but both those branches are below the “low” value, it will go and select the branch with has the most free space, even if the parentdir does not exist, including another branch where the parentdir does not exist. Here’s where I’m running into the issue: 1. Copy 2GB file to /mnt/media/music/artist/file.mp4 2. the “parentdir” /music/artist exists on 2 of the branches that fall below the low level (WD-WMC4N0751110 and WD-WMC4N0855507, both around 32-34GB left) 3. The file does not get copied to WD-WMAZA4509546 (which has 1.2TB left), but instead WD-WMC4N0855507, which is the branch where the parentdir exists that contains the most free space (out of the two). My understanding should be that seeing as both disks fall below the “low” marker, the file should be copied to the branch with 1.2TB left, regardless if the parentdir exists on that branch. It is fully possible that I am misinterpreting the manual. If I mount with mfs, all writes go to the 1.2TB disk as expected. However, I am trying to avoid using mfs because I’d like to reduce fragmentation of the files across branches (where pmfsrr comes in), but still avoid the dreaded “out of space” error that will surely happen if I continue to use pmfsrr. The other reason I’m not a big fan of mfs is that if you have 2x3TB drives, they will “ping pong” (copying one file one place, one file another, I usually deal with 2-25GB files) with each other, which isn’t ideal. Can someone shed some light on this? I’ve been able to easily recreate my situation in my test environment and I can confirm that if the parentdir does not exist on a branch with pmfsrr, it will not copy a file to that branch (which would include creating the directory structure up to the point where the file is to be copied). Many thanks! J. -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/
Re: pmfsrr mode
Hello, I have applied the patch, at least Iâm quite sure I did. Here is a link to the new syslog: https://dl.dropboxusercontent.com/u/26943/syslog-20150403.zip Let me know what else I can do to help. Cheers, On Thu, Apr 2, 2015 at 11:55 PM, sf...@users.sourceforge.net [1]sf...@users.sourceforge.net wrote: Jean-Ray Arseneau: I have included linked to the files. They are: Ok thanx. The log shows the expected behaviour, but the result is wrong. To investigate more, would you apply this debug print patch and try again? This patch doesn't solve the problem, but help investigating. Original J. R. a.patch.bz2 a.patch.bz2 References 1. mailto:sf...@users.sourceforge.net -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/
Re: pmfsrr mode
Hello, Apologies, I sent the wrong log file. Here is the correct one, I am quite sure the patch is installed, as I see lines like this one: aufs au_wbr_create_mfsrr:533:cp[3711]: DEBUG: mfsrr_bytes 42183135232, mfsrr_watermark 107374182400 Link to file: https://dl.dropboxusercontent.com/u/26943/syslog-20150403-2.zip Cheers, Jean On Fri, Apr 3, 2015 at 10:10 PM, sf...@users.sourceforge.net [1]sf...@users.sourceforge.net wrote: Jean-Ray Arseneau: I have applied the patch, at least I=E2=80=99m quite sure I did. The debug patch doesn't seem to be applied. Are you sure that you have loaded the newly compiled module? J. R. Okajima References 1. mailto:sf...@users.sourceforge.net -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/
Re: pmfsrr mode
Absolutely On Sat, Apr 4, 2015 at 1:30 AM, sf...@users.sourceforge.net [1]sf...@users.sourceforge.net wrote: Jean-Ray Arseneau: Apologies, I sent the wrong log file. Here is the correct one, I am quite sure the patch is installed, as I see = lines like this one: Ok thanx, confirmed the patch was applied. The strange thing is that aufs considers there are only 6 writable branches, while you specified 8 writable branches. The missing two are - br2, WD-WCC4E5AFUJZK - br7, WD-WMAZA4509546 and br7 is what you expect as the target. If I write more patch to investigate this point, would you test again? J. R. Okajima References 1. mailto:sf...@users.sourceforge.net -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/
Re: pmfsrr mode
Hereâs the updated log after applying the latest debug b.patch: https://dl.dropboxusercontent.com/u/26943/syslog-20150404.zip Jean On Sat, Apr 4, 2015 at 11:53 AM, sf...@users.sourceforge.net [1]sf...@users.sourceforge.net wrote: Jean-Ray Arseneau: Absolutely Here is an additional debug patch. J. R. Okajima b.patch.bz2 b.patch.bz2 References 1. mailto:sf...@users.sourceforge.net -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/
