[Gluster-users] 3.8.3 Bitrot signature process

Kotresh Hiremath Ravishankar khiremat at redhat.com
Thu Sep 22 06:14:29 UTC 2016


Hi Amudhan,

Thanks for the confirmation. If that's the case please try with dist-rep volume,
and see if you are observing similar behavior.

In any case please raise a bug for the same with your observations. We will work
on it.

Thanks and Regards,
Kotresh H R

----- Original Message -----
> From: "Amudhan P" <amudhan83 at gmail.com>
> To: "Kotresh Hiremath Ravishankar" <khiremat at redhat.com>
> Cc: "Gluster Users" <gluster-users at gluster.org>
> Sent: Thursday, September 22, 2016 11:25:28 AM
> Subject: Re: 3.8.3 Bitrot signature process
> 
> Hi Kotresh,
> 
> 2280 is a brick process, i have not tried with dist-rep volume?
> 
> I have not seen any fd in bitd process in any of the node's and bitd
> process usage always 0% CPU and randomly it goes 0.3% CPU.
> 
> 
> 
> Thanks,
> Amudhan
> 
> On Thursday, September 22, 2016, Kotresh Hiremath Ravishankar <
> khiremat at redhat.com> wrote:
> > Hi Amudhan,
> >
> > No, bitrot signer is a different process by itself and is not part of
> brick process.
> > I believe the process 2280 is a brick process ? Did you check with
> dist-rep volume?
> > Is the same behavior being observed there as well? We need to figure out
> why brick
> > process is holding that fd for such a long time.
> >
> > Thanks and Regards,
> > Kotresh H R
> >
> > ----- Original Message -----
> >> From: "Amudhan P" <amudhan83 at gmail.com>
> >> To: "Kotresh Hiremath Ravishankar" <khiremat at redhat.com>
> >> Sent: Wednesday, September 21, 2016 8:15:33 PM
> >> Subject: Re: [Gluster-users] 3.8.3 Bitrot signature process
> >>
> >> Hi Kotresh,
> >>
> >> As soon as fd closes from brick1 pid, i can see bitrot signature for the
> >> file in brick.
> >>
> >> So, it looks like fd opened by brick process to calculate signature.
> >>
> >> output of the file:
> >>
> >> -rw-r--r-- 2 root root 250M Sep 21 18:32
> >> /media/disk1/brick1/data/G/test59-bs10M-c100.nul
> >>
> >> getfattr: Removing leading '/' from absolute path names
> >> # file: media/disk1/brick1/data/G/test59-bs10M-c100.nul
> >> trusted.bit-rot.signature=0x010200000000000000e9474e4cc6
> 73c0c227a6e807e04aa4ab1f88d3744243950a290869c53daa65df
> >> trusted.bit-rot.version=0x020000000000000057d6af3200012a13
> >> trusted.ec.config=0x0000080501000200
> >> trusted.ec.size=0x000000003e800000
> >> trusted.ec.version=0x0000000000001f400000000000001f40
> >> trusted.gfid=0x4c091145429448468fffe358482c63e1
> >>
> >> stat /media/disk1/brick1/data/G/test59-bs10M-c100.nul
> >>   File: ‘/media/disk1/brick1/data/G/test59-bs10M-c100.nul’
> >>   Size: 262144000       Blocks: 512000     IO Block: 4096   regular file
> >> Device: 811h/2065d      Inode: 402653311   Links: 2
> >> Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
> >> Access: 2016-09-21 18:34:43.722712751 +0530
> >> Modify: 2016-09-21 18:32:41.650712946 +0530
> >> Change: 2016-09-21 19:14:41.698708914 +0530
> >>  Birth: -
> >>
> >>
> >> In other 2 bricks in same set, still signature is not updated for the
> same
> >> file.
> >>
> >>
> >> On Wed, Sep 21, 2016 at 6:48 PM, Amudhan P <amudhan83 at gmail.com> wrote:
> >>
> >> > Hi Kotresh,
> >> >
> >> > I am very sure, No read was going on from mount point.
> >> >
> >> > Again i did same test but after writing data to mount point. I have
> >> > unmounted mount point.
> >> >
> >> > after 120 seconds i am seeing this file fd entry in brick 1 pid
> >> >
> >> > getfattr -m. -e hex -d test59-bs10
> >> > # file: test59-bs10M-c100.nul
> >> > trusted.bit-rot.version=0x020000000000000057bed574000ed534
> >> > trusted.ec.config=0x0000080501000200
> >> > trusted.ec.size=0x000000003e800000
> >> > trusted.ec.version=0x0000000000001f400000000000001f40
> >> > trusted.gfid=0x4c091145429448468fffe358482c63e1
> >> >
> >> >
> >> > ls -l /proc/2280/fd
> >> > lr-x------ 1 root root 64 Sep 21 13:08 19 -> /media/disk1/brick1/.
> >> > glusterfs/4c/09/4c091145-4294-4846-8fff-e358482c63e1
> >> >
> >> > Volume is a EC - 4+1
> >> >
> >> > On Wed, Sep 21, 2016 at 6:17 PM, Kotresh Hiremath Ravishankar <
> >> > khiremat at redhat.com> wrote:
> >> >
> >> >> Hi Amudhan,
> >> >>
> >> >> If you see the ls output, some process has a fd opened in the backend.
> >> >> That is the reason bitrot is not considering for the signing.
> >> >> Could you please observe, after 120 secs of closure of
> >> >> "/media/disk2/brick2/.glusterfs/6e/7c/6e7c49e6-094e-4435-
> >> >> 85bf-f21f99fd8764"
> >> >> the signing happens. If so we need to figure out who holds this fd for
> >> >> such a long time.
> >> >> And also we need to figure is this issue specific to EC volume.
> >> >>
> >> >> Thanks and Regards,
> >> >> Kotresh H R
> >> >>
> >> >> ----- Original Message -----
> >> >> > From: "Amudhan P" <amudhan83 at gmail.com>
> >> >> > To: "Kotresh Hiremath Ravishankar" <khiremat at redhat.com>
> >> >> > Cc: "Gluster Users" <gluster-users at gluster.org>
> >> >> > Sent: Wednesday, September 21, 2016 4:56:40 PM
> >> >> > Subject: Re: [Gluster-users] 3.8.3 Bitrot signature process
> >> >> >
> >> >> > Hi Kotresh,
> >> >> >
> >> >> >
> >> >> > Writing new file.
> >> >> >
> >> >> > getfattr -m. -e hex -d /media/disk2/brick2/data/G/
> test58-bs10M-c100.nul
> >> >> > getfattr: Removing leading '/' from absolute path names
> >> >> > # file: media/disk2/brick2/data/G/test58-bs10M-c100.nul
> >> >> > trusted.bit-rot.version=0x020000000000000057da8b23000b120e
> >> >> > trusted.ec.config=0x0000080501000200
> >> >> > trusted.ec.size=0x000000003e800000
> >> >> > trusted.ec.version=0x0000000000001f400000000000001f40
> >> >> > trusted.gfid=0x6e7c49e6094e443585bff21f99fd8764
> >> >> >
> >> >> >
> >> >> > Running ls -l in brick 2 pid
> >> >> >
> >> >> > ls -l /proc/30162/fd
> >> >> >
> >> >> > lr-x------ 1 root root 64 Sep 21 16:22 59 ->
> >> >> > /media/disk2/brick2/.glusterfs/quanrantine
> >> >> > lrwx------ 1 root root 64 Sep 21 16:22 6 ->
> >> >> > /var/lib/glusterd/vols/glsvol1/run/10.1.2.2-media-disk2-brick2.pid
> >> >> > lr-x------ 1 root root 64 Sep 21 16:25 60 ->
> >> >> > /media/disk2/brick2/.glusterfs/6e/7c/6e7c49e6-094e-4435-
> >> >> 85bf-f21f99fd8764
> >> >> > lr-x------ 1 root root 64 Sep 21 16:22 61 ->
> >> >> > /media/disk2/brick2/.glusterfs/quanrantine
> >> >> >
> >> >> >
> >> >> > find /media/disk2/ -samefile
> >> >> > /media/disk2/brick2/.glusterfs/6e/7c/6e7c49e6-094e-4435-
> >> >> 85bf-f21f99fd8764
> >> >> > /media/disk2/brick2/.glusterfs/6e/7c/6e7c49e6-094e-4435-
> >> >> 85bf-f21f99fd8764
> >> >> > /media/disk2/brick2/data/G/test58-bs10M-c100.nul
> >> >> >
> >> >> >
> >> >> >
> >> >> > On Wed, Sep 21, 2016 at 3:28 PM, Kotresh Hiremath Ravishankar <
> >> >> > khiremat at redhat.com> wrote:
> >> >> >
> >> >> > > Hi Amudhan,
> >> >> > >
> >> >> > > Don't grep for the filename, glusterfs maintains hardlink in
> >> >> .glusterfs
> >> >> > > directory
> >> >> > > for each file. Just check 'ls -l /proc/<respective brick pid>/fd'
> for
> >> >> any
> >> >> > > fds opened
> >> >> > > for a file in .glusterfs and check if it's the same file.
> >> >> > >
> >> >> > > Thanks and Regards,
> >> >> > > Kotresh H R
> >> >> > >
> >> >> > > ----- Original Message -----
> >> >> > > > From: "Amudhan P" <amudhan83 at gmail.com>
> >> >> > > > To: "Kotresh Hiremath Ravishankar" <khiremat at redhat.com>
> >> >> > > > Cc: "Gluster Users" <gluster-users at gluster.org>
> >> >> > > > Sent: Wednesday, September 21, 2016 1:33:10 PM
> >> >> > > > Subject: Re: [Gluster-users] 3.8.3 Bitrot signature process
> >> >> > > >
> >> >> > > > Hi Kotresh,
> >> >> > > >
> >> >> > > > i have used below command to verify any open fd for file.
> >> >> > > >
> >> >> > > > "ls -l /proc/*/fd | grep filename".
> >> >> > > >
> >> >> > > > as soon as write completes there no open fd's, if there is any
> >> >> alternate
> >> >> > > > option. please let me know will also try that.
> >> >> > > >
> >> >> > > >
> >> >> > > >
> >> >> > > >
> >> >> > > > Also, below is my scrub status in my test setup. number of
> skipped
> >> >> files
> >> >> > > > slow reducing day by day. I think files are skipped due to
> bitrot
> >> >> > > signature
> >> >> > > > process is not completed yet.
> >> >> > > >
> >> >> > > > where can i see scrub skipped files?
> >> >> > > >
> >> >> > > >
> >> >> > > > Volume name : glsvol1
> >> >> > > >
> >> >> > > > State of scrub: Active (Idle)
> >> >> > > >
> >> >> > > > Scrub impact: normal
> >> >> > > >
> >> >> > > > Scrub frequency: daily
> >> >> > > >
> >> >> > > > Bitrot error log location: /var/log/glusterfs/bitd.log
> >> >> > > >
> >> >> > > > Scrubber error log location: /var/log/glusterfs/scrub.log
> >> >> > > >
> >> >> > > >
> >> >> > > > =========================================================
> >> >> > > >
> >> >> > > > Node: localhost
> >> >> > > >
> >> >> > > > Number of Scrubbed files: 1644
> >> >> > > >
> >> >> > > > Number of Skipped files: 1001
> >> >> > > >
> >> >> > > > Last completed scrub time: 2016-09-20 11:59:58
> >> >> > > >
> >> >> > > > Duration of last scrub (D:M:H:M:S): 0:0:39:26
> >> >> > > >
> >> >> > > > Error count: 0
> >> >> > > >
> >> >> > > >
> >> >> > > > =========================================================
> >> >> > > >
> >> >> > > > Node: 10.1.2.3
> >> >> > > >
> >> >> > > > Number of Scrubbed files: 1644
> >> >> > > >
> >> >> > > > Number of Skipped files: 1001
> >> >> > > >
> >> >> > > > Last completed scrub time: 2016-09-20 10:50:00
> >> >> > > >
> >> >> > > > Duration of last scrub (D:M:H:M:S): 0:0:38:17
> >> >> > > >
> >> >> > > > Error count: 0
> >> >> > > >
> >> >> > > >
> >> >> > > > =========================================================
> >> >> > > >
> >> >> > > > Node: 10.1.2.4
> >> >> > > >
> >> >> > > > Number of Scrubbed files: 981
> >> >> > > >
> >> >> > > > Number of Skipped files: 1664
> >> >> > > >
> >> >> > > > Last completed scrub time: 2016-09-20 12:38:01
> >> >> > > >
> >> >> > > > Duration of last scrub (D:M:H:M:S): 0:0:35:19
> >> >> > > >
> >> >> > > > Error count: 0
> >> >> > > >
> >> >> > > >
> >> >> > > > =========================================================
> >> >> > > >
> >> >> > > > Node: 10.1.2.1
> >> >> > > >
> >> >> > > > Number of Scrubbed files: 1263
> >> >> > > >
> >> >> > > > Number of Skipped files: 1382
> >> >> > > >
> >> >> > > > Last completed scrub time: 2016-09-20 11:57:21
> >> >> > > >
> >> >> > > > Duration of last scrub (D:M:H:M:S): 0:0:37:17
> >> >> > > >
> >> >> > > > Error count: 0
> >> >> > > >
> >> >> > > >
> >> >> > > > =========================================================
> >> >> > > >
> >> >> > > > Node: 10.1.2.2
> >> >> > > >
> >> >> > > > Number of Scrubbed files: 1644
> >> >> > > >
> >> >> > > > Number of Skipped files: 1001
> >> >> > > >
> >> >> > > > Last completed scrub time: 2016-09-20 11:59:25
> >> >> > > >
> >> >> > > > Duration of last scrub (D:M:H:M:S): 0:0:39:18
> >> >> > > >
> >> >> > > > Error count: 0
> >> >> > > >
> >> >> > > > =========================================================
> >> >> > > >
> >> >> > > >
> >> >> > > >
> >> >> > > >
> >> >> > > > Thanks
> >> >> > > > Amudhan
> >> >> > > >
> >> >> > > >
> >> >> > > > On Wed, Sep 21, 2016 at 11:45 AM, Kotresh Hiremath Ravishankar <
> >> >> > > > khiremat at redhat.com> wrote:
> >> >> > > >
> >> >> > > > > Hi Amudhan,
> >> >> > > > >
> >> >> > > > > I don't think it's the limitation with read data from the
> brick.
> >> >> > > > > To limit the usage of CPU, throttling is done using token
> bucket
> >> >> > > > > algorithm. The log message showed is related to it. But even
> then
> >> >> > > > > I think it should not take 12 minutes for check-sum
> calculation
> >> >> unless
> >> >> > > > > there is an fd open (might be internal). Could you please
> cross
> >> >> verify
> >> >> > > > > if there are any fd opened on that file by looking into
> /proc? I
> >> >> will
> >> >> > > > > also test it out in the mean time and get back to you.
> >> >> > > > >
> >> >> > > > > Thanks and Regards,
> >> >> > > > > Kotresh H R
> >> >> > > > >
> >> >> > > > > ----- Original Message -----
> >> >> > > > > > From: "Amudhan P" <amudhan83 at gmail.com>
> >> >> > > > > > To: "Kotresh Hiremath Ravishankar" <khiremat at redhat.com>
> >> >> > > > > > Cc: "Gluster Users" <gluster-users at gluster.org>
> >> >> > > > > > Sent: Tuesday, September 20, 2016 3:19:28 PM
> >> >> > > > > > Subject: Re: [Gluster-users] 3.8.3 Bitrot signature process
> >> >> > > > > >
> >> >> > > > > > Hi Kotresh,
> >> >> > > > > >
> >> >> > > > > > Please correct me if i am wrong, Once a file write completes
> >> >> and as
> >> >> > > soon
> >> >> > > > > as
> >> >> > > > > > closes fds, bitrot waits for 120 seconds and starts hashing
> and
> >> >> > > update
> >> >> > > > > > signature for the file in brick.
> >> >> > > > > >
> >> >> > > > > > But, what i am feeling that bitrot takes too much of time to
> >> >> complete
> >> >> > > > > > hashing.
> >> >> > > > > >
> >> >> > > > > > below is test result i would like to share.
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > > writing data in below path using dd :
> >> >> > > > > >
> >> >> > > > > > /mnt/gluster/data/G (mount point)
> >> >> > > > > > -rw-r--r-- 1 root root  10M Sep 20 12:19 test53-bs10M-c1.nul
> >> >> > > > > > -rw-r--r-- 1 root root 100M Sep 20 12:19
> test54-bs10M-c10.nul
> >> >> > > > > >
> >> >> > > > > > No any other write or read process is going on.
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > > Checking file data in one of the brick.
> >> >> > > > > >
> >> >> > > > > > -rw-r--r-- 2 root root 2.5M Sep 20 12:23 test53-bs10M-c1.nul
> >> >> > > > > > -rw-r--r-- 2 root root  25M Sep 20 12:23
> test54-bs10M-c10.nul
> >> >> > > > > >
> >> >> > > > > > file's stat and getfattr info from brick, after write
> process
> >> >> > > completed.
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ stat
> >> >> test53-bs10M-c1.nul
> >> >> > > > > >   File: ‘test53-bs10M-c1.nul’
> >> >> > > > > >   Size: 2621440         Blocks: 5120       IO Block: 4096
> >> >>  regular
> >> >> > > file
> >> >> > > > > > Device: 821h/2081d      Inode: 536874168   Links: 2
> >> >> > > > > > Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (
>   0/
> >> >> > > root)
> >> >> > > > > > Access: 2016-09-20 12:23:28.798886647 +0530
> >> >> > > > > > Modify: 2016-09-20 12:23:28.994886646 +0530
> >> >> > > > > > Change: 2016-09-20 12:23:28.998886646 +0530
> >> >> > > > > >  Birth: -
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ stat
> >> >> test54-bs10M-c10.nul
> >> >> > > > > >   File: ‘test54-bs10M-c10.nul’
> >> >> > > > > >   Size: 26214400        Blocks: 51200      IO Block: 4096
> >> >>  regular
> >> >> > > file
> >> >> > > > > > Device: 821h/2081d      Inode: 536874169   Links: 2
> >> >> > > > > > Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (
>   0/
> >> >> > > root)
> >> >> > > > > > Access: 2016-09-20 12:23:42.902886624 +0530
> >> >> > > > > > Modify: 2016-09-20 12:23:44.378886622 +0530
> >> >> > > > > > Change: 2016-09-20 12:23:44.378886622 +0530
> >> >> > > > > >  Birth: -
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ sudo getfattr -m.
> -e
> >> >> hex -d
> >> >> > > > > > test53-bs10M-c1.nul
> >> >> > > > > > # file: test53-bs10M-c1.nul
> >> >> > > > > > trusted.bit-rot.version=0x020000000000000057daa7b50002e5b4
> >> >> > > > > > trusted.ec.config=0x0000080501000200
> >> >> > > > > > trusted.ec.size=0x0000000000a00000
> >> >> > > > > > trusted.ec.version=0x00000000000000500000000000000050
> >> >> > > > > > trusted.gfid=0xe2416bd1aae4403c88f44286273bbe99
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ sudo getfattr -m.
> -e
> >> >> hex -d
> >> >> > > > > > test54-bs10M-c10.nul
> >> >> > > > > > # file: test54-bs10M-c10.nul
> >> >> > > > > > trusted.bit-rot.version=0x020000000000000057daa7b50002e5b4
> >> >> > > > > > trusted.ec.config=0x0000080501000200
> >> >> > > > > > trusted.ec.size=0x0000000006400000
> >> >> > > > > > trusted.ec.version=0x00000000000003200000000000000320
> >> >> > > > > > trusted.gfid=0x54e018dd8c5a4bd79e0317729d8a57c5
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > > file's stat and getfattr info from brick, after bitrot
> signature
> >> >> > > updated.
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ stat
> >> >> test53-bs10M-c1.nul
> >> >> > > > > >   File: ‘test53-bs10M-c1.nul’
> >> >> > > > > >   Size: 2621440         Blocks: 5120       IO Block: 4096
> >> >>  regular
> >> >> > > file
> >> >> > > > > > Device: 821h/2081d      Inode: 536874168   Links: 2
> >> >> > > > > > Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (
>   0/
> >> >> > > root)
> >> >> > > > > > Access: 2016-09-20 12:25:31.494886450 +0530
> >> >> > > > > > Modify: 2016-09-20 12:23:28.994886646 +0530
> >> >> > > > > > Change: 2016-09-20 12:27:00.994886307 +0530
> >> >> > > > > >  Birth: -
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ sudo getfattr -m.
> -e
> >> >> hex -d
> >> >> > > > > > test53-bs10M-c1.nul
> >> >> > > > > > # file: test53-bs10M-c1.nul
> >> >> > > > > > trusted.bit-rot.signature=0x0102000000000000006de7493c5c
> >> >> > > > > 90f643357c268fbaaf461c1567e0334e4948023ce17268403aa37a
> >> >> > > > > > trusted.bit-rot.version=0x020000000000000057daa7b50002e5b4
> >> >> > > > > > trusted.ec.config=0x0000080501000200
> >> >> > > > > > trusted.ec.size=0x0000000000a00000
> >> >> > > > > > trusted.ec.version=0x00000000000000500000000000000050
> >> >> > > > > > trusted.gfid=0xe2416bd1aae4403c88f44286273bbe99
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ stat
> >> >> test54-bs10M-c10.nul
> >> >> > > > > >   File: ‘test54-bs10M-c10.nul’
> >> >> > > > > >   Size: 26214400        Blocks: 51200      IO Block: 4096
> >> >>  regular
> >> >> > > file
> >> >> > > > > > Device: 821h/2081d      Inode: 536874169   Links: 2
> >> >> > > > > > Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (
>   0/
> >> >> > > root)
> >> >> > > > > > Access: 2016-09-20 12:25:47.510886425 +0530
> >> >> > > > > > Modify: 2016-09-20 12:23:44.378886622 +0530
> >> >> > > > > > Change: 2016-09-20 12:38:05.954885243 +0530
> >> >> > > > > >  Birth: -
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ sudo getfattr -m.
> -e
> >> >> hex -d
> >> >> > > > > > test54-bs10M-c10.nul
> >> >> > > > > > # file: test54-bs10M-c10.nul
> >> >> > > > > > trusted.bit-rot.signature=0x010200000000000000394c345f0b
> >> >> > > > > 0c63ee652627a62eed069244d35c4d5134e4f07d4eabb51afda47e
> >> >> > > > > > trusted.bit-rot.version=0x020000000000000057daa7b50002e5b4
> >> >> > > > > > trusted.ec.config=0x0000080501000200
> >> >> > > > > > trusted.ec.size=0x0000000006400000
> >> >> > > > > > trusted.ec.version=0x00000000000003200000000000000320
> >> >> > > > > > trusted.gfid=0x54e018dd8c5a4bd79e0317729d8a57c5
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > > (Actual time taken for reading file from brick for md5sum)
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ time md5sum
> >> >> > > test53-bs10M-c1.nul
> >> >> > > > > > 8354dcaa18a1ecb52d0895bf00888c44  test53-bs10M-c1.nul
> >> >> > > > > >
> >> >> > > > > > real    0m0.045s
> >> >> > > > > > user    0m0.007s
> >> >> > > > > > sys     0m0.003s
> >> >> > > > > >
> >> >> > > > > > gfstst-node5:/media/disk2/brick2/data/G$ time md5sum
> >> >> > > > > test54-bs10M-c10.nul
> >> >> > > > > > bed3c0a4a1407f584989b4009e9ce33f  test54-bs10M-c10.nul
> >> >> > > > > >
> >> >> > > > > > real    0m0.166s
> >> >> > > > > > user    0m0.062s
> >> >> > > > > > sys     0m0.011s
> >> >> > > > > >
> >> >> > > > > > As you can see that 'test54-bs10M-c10.nul' file took around
> 12
> >> >> > > minutes to
> >> >> > > > > > update bitort signature (pls refer stat output for the
> file).
> >> >> > > > > >
> >> >> > > > > > what would be the cause for such a slow read?. Any
> limitation
> >> >> in read
> >> >> > > > > data
> >> >> > > > > > from brick?
> >> >> > > > > >
> >> >> > > > > > Also, i am seeing this line bitd.log, what does this mean?
> >> >> > > > > > [bit-rot.c:1784:br_rate_limit_signer] 0-glsvol1-bit-rot-0:
> >> >> [Rate
> >> >> > > Limit
> >> >> > > > > > Info] "tokens/sec (rate): 131072, maxlimit: 524288
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > > Thanks
> >> >> > > > > > Amudhan P
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > >
> >> >> > > > > > On Mon, Sep 19, 2016 at 1:00 PM, Kotresh Hiremath
> Ravishankar <
> >> >> > > > > > khiremat at redhat.com> wrote:
> >> >> > > > > >
> >> >> > > > > > > Hi Amudhan,
> >> >> > > > > > >
> >> >> > > > > > > Thanks for testing out the bitrot feature and sorry for
> the
> >> >> delayed
> >> >> > > > > > > response.
> >> >> > > > > > > Please find the answers inline.
> >> >> > > > > > >
> >> >> > > > > > > Thanks and Regards,
> >> >> > > > > > > Kotresh H R
> >> >> > > > > > >
> >> >> > > > > > > ----- Original Message -----
> >> >> > > > > > > > From: "Amudhan P" <amudhan83 at gmail.com>
> >> >> > > > > > > > To: "Gluster Users" <gluster-users at gluster.org>
> >> >> > > > > > > > Sent: Friday, September 16, 2016 4:14:10 PM
> >> >> > > > > > > > Subject: Re: [Gluster-users] 3.8.3 Bitrot signature
> process
> >> >> > > > > > > >
> >> >> > > > > > > > Hi,
> >> >> > > > > > > >
> >> >> > > > > > > > Can anyone reply to this mail.
> >> >> > > > > > > >
> >> >> > > > > > > > On Tue, Sep 13, 2016 at 12:49 PM, Amudhan P <
> >> >> > > amudhan83 at gmail.com >
> >> >> > > > > > > wrote:
> >> >> > > > > > > >
> >> >> > > > > > > >
> >> >> > > > > > > >
> >> >> > > > > > > > Hi,
> >> >> > > > > > > >
> >> >> > > > > > > > I am testing bitrot feature in Gluster 3.8.3 with
> disperse
> >> >> EC
> >> >> > > volume
> >> >> > > > > 4+1.
> >> >> > > > > > > >
> >> >> > > > > > > > When i write single small file (< 10MB) after 2 seconds
> i
> >> >> can see
> >> >> > > > > bitrot
> >> >> > > > > > > > signature in bricks for the file, but when i write
> multiple
> >> >> files
> >> >> > > > > with
> >> >> > > > > > > > different size ( > 10MB) it takes long time (> 24hrs)
> to see
> >> >> > > bitrot
> >> >> > > > > > > > signature in all the files.
> >> >> > > > > > >
> >> >> > > > > > >    The default timeout for signing to happen is 120
> seconds.
> >> >> So the
> >> >> > > > > > > signing will happen
> >> >> > > > > > >   120 secs after the last fd gets closed on that file. So
> if
> >> >> the
> >> >> > > file
> >> >> > > > > is
> >> >> > > > > > > being written
> >> >> > > > > > >   continuously, it will not be signed until 120 secs after
> >> >> it's
> >> >> > > last
> >> >> > > > > fd is
> >> >> > > > > > > closed.
> >> >> > > > > > > >
> >> >> > > > > > > > My questions are.
> >> >> > > > > > > > 1. I have enabled scrub schedule as hourly and throttle
> as
> >> >> > > normal,
> >> >> > > > > does
> >> >> > > > > > > this
> >> >> > > > > > > > make any impact in delaying bitrot signature?
> >> >> > > > > > >       No.
> >> >> > > > > > > > 2. other than "bitd.log" where else i can watch current
> >> >> status of
> >> >> > > > > bitrot,
> >> >> > > > > > > > like number of files added for signature and file
> status?
> >> >> > > > > > >      Signature will happen after 120 sec of last fd
> closure,
> >> >> as
> >> >> > > said
> >> >> > > > > above.
> >> >> > > > > > >      There is not status command which tracks the
> signature
> >> >> of the
> >> >> > > > > files.
> >> >> > > > > > >      But there is bitrot status command which tracks the
> >> >> number of
> >> >> > > > > files
> >> >> > > > > > >      scrubbed.
> >> >> > > > > > >
> >> >> > > > > > >      #gluster vol bitrot <volname> scrub status
> >> >> > > > > > >
> >> >> > > > > > >
> >> >> > > > > > > > 3. where i can confirm that all the files in the brick
> are
> >> >> bitrot
> >> >> > > > > signed?
> >> >> > > > > > >
> >> >> > > > > > >      As said, signing information of all the files is not
> >> >> tracked.
> >> >> > > > > > >
> >> >> > > > > > > > 4. is there any file read size limit in bitrot?
> >> >> > > > > > >
> >> >> > > > > > >      I didn't get. Could you please elaborate this ?
> >> >> > > > > > >
> >> >> > > > > > > > 5. options for tuning bitrot for faster signing of
> files?
> >> >> > > > > > >
> >> >> > > > > > >      Bitrot feature is mainly to detect silent corruption
> >> >> > > (bitflips) of
> >> >> > > > > > > files due to long
> >> >> > > > > > >      term storage. Hence the default is 120 sec of last fd
> >> >> > > closure, the
> >> >> > > > > > > signing happens.
> >> >> > > > > > >      But there is a tune able which can change the default
> >> >> 120 sec
> >> >> > > but
> >> >> > > > > > > that's only for
> >> >> > > > > > >      testing purposes and we don't recommend it.
> >> >> > > > > > >
> >> >> > > > > > >       gluster vol get master features.expiry-time
> >> >> > > > > > >
> >> >> > > > > > >      For testing purposes, you can change this default and
> >> >> test.
> >> >> > > > > > > >
> >> >> > > > > > > > Thanks
> >> >> > > > > > > > Amudhan
> >> >> > > > > > > >
> >> >> > > > > > > >
> >> >> > > > > > > > _______________________________________________
> >> >> > > > > > > > Gluster-users mailing list
> >> >> > > > > > > > Gluster-users at gluster.org
> >> >> > > > > > > > http://www.gluster.org/mailman/listinfo/gluster-users
> >> >> > > > > > >
> >> >> > > > > >
> >> >> > > > >
> >> >> > > >
> >> >> > >
> >> >> >
> >> >>
> >> >
> >> >
> >>
> >
> 


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