Adding a disk fails
Well I've just tried to add a disk to another, but it fails. I created the first (starting with no traditional partitions) with:
# mkfs.btrfs /dev/sdb
Then I mounted it to /media/backups and put lots of files on it. I shut down the system, added another disk. Set it up with:
# mkfs.btrfs /dev/sdc WARNING! - Btrfs Btrfs v0.19 IS EXPERIMENTAL WARNING! - see http://btrfs.wiki.kernel.org before using fs created label (null) on /dev/sdc nodesize 4096 leafsize 4096 sectorsize 4096 size 1.82TB Btrfs Btrfs v0.19 # btrfs device scan Scanning for Btrfs filesystems # (... Nothing? Not even my known mounted sdb drive?) # btrfs device add /dev/sdc /media/backups ERROR: error adding the device '/dev/sdc'
It gives no clue as to what might possibly be the problem. I want raid0.
Also I can not understand this:
"Note: While subvolumes can be created anywhere in the filesystem tree, in order to be mounted by name a subvolume or snapshot must be in the root of the btrfs filesystem."
I want to do this, but do not know what this means. Tentatively I've created a BTRFS volume and mounted it on /media/backups. I then created subvolumes as backup-hex, backup-droog, snaps-hex and snaps-droog. When I created a snapshot it created a subdir under snaps-hex called hex-root.
It won't allow me to remove snapshots. (Debian Testing)
Also does anyone know how to create a shapshot with the current date in the name?
Quoted 15 lines · Carl Cook
Well I've just tried to add a disk to another, but it fails. I created the first (starting with no traditional partitions) with: # mkfs.btrfs
/dev/sdbThen I mounted it to /media/backups and put lots of files on it. I shut down the system, added another disk. Set it up with: # mkfs.btrfs
/dev/sdcWARNING! - Btrfs Btrfs v0.19 IS EXPERIMENTAL WARNING! - see http://btrfs.wiki.kernel.org before using fs created label (null) on/dev/sdcnodesize 4096 leafsize 4096 sectorsize 4096 size 1.82TB Btrfs Btrfs v0.19 # btrfs device scan Scanning for Btrfs filesystems # (... Nothing? Not even my known mounted sdb drive?) # btrfs device add/dev/sdc/media/backups ERROR: error adding the device '/dev/sdc'
Quoted 2 lines
It gives no clue as to what might possibly be the problem. I want raid0.
To add another disk you don't have to run mkfs.btrfs. For example:
# add the first disk mkfs.btrfs /dev/sdb # mount the disk mount /dev/sdb /media/backups
# add another disk to the first one btrfs device add /dev/sdc /media/backup
Note1: the filesystem has to be mounted
Note2: the medatada will be in raid1, the data in raid0 If you shutdown the system, at the reboot you should "scan" all the device in order to find the btrfs ones
# find the btrfs device btrfs device scan
# mount the filesystem mount /dev/sdb /media/backups # you can use also /dev/sdc
Quoted 7 lines
Also I can not understand this: "Note: While subvolumes can be created anywhere in the filesystem tree, in order to be mounted by name a subvolume or snapshot must be in the root of the btrfs filesystem."
I want to do this, but do not know what this means.
Suppose to have a btrfs filesystem in /dev/sdb
mount /dev/sdb /media/backup
mkidr /media/backup/dir-1
<create a lot of file under /media/backup>
# make a snapshot btrfs filesystem snapshot /media/backup /media/backup/snapshot-2
# make another snapshot btrfs filesystem snapshot /media/backup /media/backup/dir-1/snapshot-3
# umount the filesystem umount /media/backup
# mount snapshot-2 directly mount -o subvol=snapshot-2 /dev/sdb /media/backup
# if you try to mount snapshot-3 directly, you fail because this # snapshot is not under the root of the btrfs filesystem mount -o subvol=dir-1/snapshot-3 /dev/sdb /media/backup # -> error
If you look at the output of the command "btrfs subvolume list <path>" you can find the id of every subvolume. It is possible to use this ID to mount directly a subvolume. This permits to mount a "non-root" subvolume.
Quoted 7 lines
Tentatively I've
created a BTRFS volume and mounted it on /media/backups. I then created subvolumes as backup-hex, backup-droog, snaps-hex and snaps-droog. When I created a snapshot it created a subdir under snaps-hex called hex-root.It won't allow me to remove snapshots. (Debian Testing)
Which kenel version debian testing uses ?
Quoted 2 lines
Also does anyone know how to create a shapshot with the current date in the name?
btrfs filesystem snapshot / /snapshot-$(date +"%Y-%m-%d")
Quoted 4 lines
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I must have done something wrong because for the past week or so, almost none of my questions have been answered here. I'm pretty much in trouble now because I have -no- backups, as I cannot get my backup server running, as I've put all my eggs in the btrfs basket. Am I asking things wrong, or am I supposed to be asking somewhere else?
Quoted 34 lines · On Thu 20 January 2011 13:18:40 Carl Cook wrote:
Well I've just tried to add a disk to another, but it fails. I created the first (starting with no traditional partitions) with:
# mkfs.btrfs /dev/sdbThen I mounted it to /media/backups and put lots of files on it. I shut down the system, added another disk. Set it up with:
# mkfs.btrfs /dev/sdc WARNING! - Btrfs Btrfs v0.19 IS EXPERIMENTAL WARNING! - see http://btrfs.wiki.kernel.org before using fs created label (null) on /dev/sdc nodesize 4096 leafsize 4096 sectorsize 4096 size 1.82TB Btrfs Btrfs v0.19 # btrfs device scan Scanning for Btrfs filesystems # (... Nothing? Not even my known mounted sdb drive?) # btrfs device add /dev/sdc /media/backups ERROR: error adding the device '/dev/sdc'It gives no clue as to what might possibly be the problem. I want raid0.
Also I can not understand this:
"Note: While subvolumes can be created anywhere in the filesystem tree, in order to be mounted by name a subvolume or snapshot must be in the root of the btrfs filesystem."I want to do this, but do not know what this means. Tentatively I've created a BTRFS volume and mounted it on /media/backups. I then created subvolumes as backup-hex, backup-droog, snaps-hex and snaps-droog. When I created a snapshot it created a subdir under snaps-hex called hex-root.
It won't allow me to remove snapshots. (Debian Testing)
Also does anyone know how to create a shapshot with the current date in the name? --
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Quoted 9 lines · On Thu 20 January 2011 14:13:22 Goffredo Baroncelli wrote:
To add another disk you don't have to run mkfs.btrfs. For example:
# add the first disk mkfs.btrfs /dev/sdb # mount the disk mount /dev/sdb /media/backups# add another disk to the first one btrfs device add /dev/sdc /media/backup
Thanks Goffredo but as I say, I did this and it responds with
"ERROR: error adding the device '/dev/sdc'"
... it doesn't give a clue.
Quoted 7 lines
Note1: the filesystem has to be mounted
Note2: the medatada will be in raid1, the data in raid0 If you shutdown the system, at the reboot you should "scan" all the device in order to find the btrfs ones# find the btrfs device btrfs device scan
This must be done at every boot? If so, where is recommended, in rc.local?
Quoted 3 lines
# if you try to mount snapshot-3 directly, you fail because this # snapshot is not under the root of the btrfs filesystem mount -o subvol=dir-1/snapshot-3 /dev/sdb /media/backup # -> error
This is how I'd understood it, but when creating a subvolume in the root and putting a snalshot into it, it seems to make a further subvolume (or directory) with a redundant name. This would not be under the root, and may not be mountable?
Quoted 1 line
Which kenel version debian testing uses ?
2.6.32-5-amd64 with Debian patches.
Quoted 1 line
btrfs filesystem snapshot / /snapshot-$(date +"%Y-%m-%d")
Oh thank you.
Quoted 10 lines · On Friday 21 of January 2011 00:10:54 Carl Cook wrote:
Quoted 9 lines · On Thu 20 January 2011 14:13:22 Goffredo Baroncelli wrote:
To add another disk you don't have to run mkfs.btrfs. For example:
=20# add the first disk mkfs.btrfs /dev/sdb # mount the disk mount /dev/sdb /media/backups =20 # add another disk to the first one btrfs device add /dev/sdc /media/backup
Quoted 4 lines
=20
Thanks Goffredo but as I say, I did this and it responds with
"ERROR: error adding the device '/dev/sdc'"
... it doesn't give a clue.
You still have a btrfs on /dev/sdc, do a=20
dd if=3D/dev/zero of=3D/dev/sdc bs=3D8192
(overkill, but I don't remember which blocks have to be zeroed to destr= oy=20
btrfs superblock)
Then
btrfs dev add /dev/sdc /media backup
Quoted 10 lines
=20
Quoted 7 lines
Note1: the filesystem has to be mounted
Note2: the medatada will be in raid1, the data in raid0 If you shutdown the system, at the reboot you should "scan" all the device in order to find the btrfs ones
=20# find the btrfs device btrfs device scan=20
This must be done at every boot? If so, where is recommended, in rc.=
local?
yes. rc.local is too late, unless you will also mount the volume from t= here=20
and not using /etc/fstab
--=20
Hubert Kario
QBS - Quality Business Software
02-656 Warszawa, ul. Ksawer=F3w 30/85
tel. +48 (22) 646-61-51, 646-74-24
www.qbs.com.pl
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Hallo, Goffredo,
Du meintest am 20.01.11:
Quoted 9 lines
To add another disk you don't have to run mkfs.btrfs. For example:
# add the first disk mkfs.btrfs /dev/sdb # mount the disk mount /dev/sdb /media/backups# add another disk to the first one btrfs device add /dev/sdc /media/backup
^backups
Quoted 2 lines
Note1: the filesystem has to be mounted
Note2: the medatada will be in raid1, the data in raid0
And there seems to be an error; some options tell the sum of the sizes of /dev/sdb and /dev/sdc as available size, but perhaps you can only use the size of the smaller of the two devices - the system seems to work in a kind of RAID1.
The error is known but not yet fixed.
Viele Gruesse!
Helmut
Hallo, Carl,
Du meintest am 20.01.11:
Quoted 7 lines
Quoted 5 lines
If you shutdown the system, at the reboot you should "scan" all the device in order to find the btrfs ones
# find the btrfs device btrfs device scanThis must be done at every boot?
Yes - this advice is added in the Wiki (?).
Quoted 1 line
If so, where is recommended, in rc.local?
That depends - it has to be done before mounting. And if the device is part of the boot partition then you may put the "scan" command into an init-ramdisk.
Viele Gruesse!
Helmut
Quoted 13 lines · Helmut Hullen
Hallo, Carl,
Du meintest am 20.01.11:
Quoted 7 lines
Quoted 5 lines
If you shutdown the system, at the reboot you should "scan" all the device in order to find the btrfs ones
# find the btrfs device btrfs device scanThis must be done at every boot?
Quoted 7 lines
Yes - this advice is added in the Wiki (?).
Quoted 1 line
If so, where is recommended, in rc.local?
That depends - it has to be done before mounting. And if the device is part of the boot partition then you may put the "scan" command into an init-ramdisk.
Using something like "device=/dev/sdb,device=/dev/sdc" on fstab mount options should also work.
Signature · 1 line
Fajar
Quoted 4 lines · On Thu 20 January 2011 22:55:54 Hubert Kario wrote:
You still have a btrfs on
/dev/sdc, do a
dd if=/dev/zero of=/dev/sdc bs=8192
(overkill, but I don't remember which blocks have to be zeroed to destroy btrfs superblock)
I gave up and started over. Maybe it should be clarified in the wiki that no mkfs should be done on additional volumes, as it's counterintuitive to some.
Quoted 2 lines
yes. rc.local is too late, unless you will also mount the volume from there and not using
/etc/fstab
How and when then?
Quoted 3 lines
That depends - it has to be done before mounting. And if the device is part of the boot partition then you may put the "scan" command into an init-ramdisk.
This does not seem to have been sent to the listserv, as I only got it in a reply. This is likely incomplete.
Quoted 2 lines
Using something like "device=/dev/sdb,device=/dev/sdc" on fstab mount options should also work.
You mean as a substitute for a scan?
On my other server the btrfs array seems to mount just fine without any measures to scan. I don't understand this, nor why no specific advice is given about scanning on boot in the wiki.
Quoted 4 lines · On Friday, January 21, 2011 11:16:49 [email protected] wrote:
Quoted 3 lines · On Thu 20 January 2011 22:55:54 Hubert Kario wrote:
You still have a btrfs on
/dev/sdc, do a
dd if=3D/dev/zero of=3D/dev/sdc bs=3D8192
(overkill, but I don't remember which blocks have to be zeroed to d=
estroy
Quoted 3 lines
Quoted 1 line
btrfs superblock)
=20
I gave up and started over. Maybe it should be clarified in the wiki=
that
Quoted 1 line
no mkfs should be done on additional volumes, as it's counterintuitiv=
e to
Quoted 3 lines
some.
=20Quoted 1 line
yes. rc.local is too late, unless you will also mount the volume fr=
om
Quoted 3 lines
Quoted 1 line
there and not using
/etc/fstab=20
How and when then?
in, or before /etc/rcS.d/S35mountall.sh
Quoted 2 lines
=20
Quoted 1 line
That depends - it has to be done before mounting. And if the device=
is
Quoted 1 line
Quoted 1 line
part of the boot partition then you may put the "scan" command into=
an
Quoted 3 lines
Quoted 1 line
init-ramdisk.
=20
This does not seem to have been sent to the listserv, as I only got i=
t in a
Quoted 1 line
reply. This is likely incomplete.
It was sent to list, your MUA may have merged messages with identical M= essage-
ID.
Quoted 2 lines
=20
Quoted 1 line
Using something like "device=3D/dev/sdb,device=3D/dev/sdc" on fstab=
mount
Quoted 3 lines
Quoted 1 line
options should also work.
=20
You mean as a substitute for a scan?
Would seem so, but I haven't tried this
Quoted 2 lines
=20
On my other server the btrfs array seems to mount just fine without a=
ny
Quoted 1 line
measures to scan. I don't understand this, nor why no specific advi=
ce is
Quoted 1 line
given about scanning on boot in the wiki.
your distro may have alredy put it in initrd or initramfs (for example = fedora=20
and archlinux do)
--=20
Hubert Kario
QBS - Quality Business Software
02-656 Warszawa, ul. Ksawer=F3w 30/85
tel. +48 (22) 646-61-51, 646-74-24
www.qbs.com.pl
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in
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Hallo, Goffredo,
Du meintest am 20.01.11:
Quoted 7 lines
To add another disk you don't have to run mkfs.btrfs. For example:
# add the first disk mkfs.btrfs /dev/sdb # mount the disk mount /dev/sdb /media/backups
Quoted 5 lines
# add another disk to the first one btrfs device add /dev/sdc /media/backupNote1: the filesystem has to be mounted
Note2: the medatada will be in raid1, the data in raid0
Note 3: if the disk has been used (especially under btrfs) you should first delete old partitioning data etc:
dd if=/dev/zero of=/dev/sdb count=1000
dd if=/dev/zero of=/dev/sdc count=1000I've just tried your recipe with two devices I had used for other btrfs experiments:
btrfs filesystem show 2>/dev/null
shows my new wishes, and it shows the old settings too.
But writing 1000 blocks seems to be not enough - sometimes I'll try bigger numbers. What happens with the old (and now unwanted) settings?
By the way: I nee "2>/dev/null" because the actual git version always tries to show all block devices which it finds in "/dev" (no: I don't use "udev").
Viele Gruesse!
Helmut
Hallo, Goffredo,
Du meintest am 20.01.11:
Quoted 7 lines
To add another disk you don't have to run mkfs.btrfs. For example:
# add the first disk mkfs.btrfs /dev/sdb # mount the disk mount /dev/sdb /media/backups
Quoted 5 lines
# add another disk to the first one btrfs device add /dev/sdc /media/backupNote1: the filesystem has to be mounted
Note2: the medatada will be in raid1, the data in raid0
I've just tried ...
creating /dev/sde with 2 TByte
adding /dev/sdf with 60 GByte (it's easier to check "ENOSPACE" with such a small device)
copying 94 Gbyte
and then
btrfs filesystem balance /mnt/btr
(needed about 40 minutes for 94 GByte)
leads to
# btrfs filesystem show Label: none uuid: 121ae2ed-f572-43e6-8855-cd66ad534401 Total devices 2 FS bytes used 94.68GB devid 2 size 37.27GB used 37.00GB path /dev/sdf devid 1 size 1.82TB used 63.04GB path /dev/sde
Label: 'MM2' uuid: ad7c0668-316c-4a79-ba00-3b505b9d99b4
Total devices 2 FS bytes used 1.15TB
devid 1 size 1.81TB used 591.14GB path /dev/sde2
*** Some devices missing
Btrfs Btrfs v0.19
# btrfs filesystem df /mnt/btr Data, RAID0: total=4.00GB, used=2.00GB Data: total=94.01GB, used=92.58GB System, DUP: total=8.00MB, used=16.00KB System: total=4.00MB, used=0.00 Metadata, DUP: total=1.00GB, used=111.87MB Metadata: total=8.00MB, used=0.00
# df -t btrfs Filesystem Type 1K-blocks Used Available Use% Mounted on /dev/sde btrfs 1992597264 99396500 1891304076 5% /mnt/btr
# fdisk -l
# btrfs filesystem show Label: none uuid: 121ae2ed-f572-43e6-8855-cd66ad534401 Total devices 2 FS bytes used 93.68GB devid 2 size 37.27GB used 36.12GB path /dev/sdf devid 1 size 1.82TB used 93.16GB path /dev/sde
Label: 'MM2' uuid: ad7c0668-316c-4a79-ba00-3b505b9d99b4
Total devices 2 FS bytes used 1.15TB
devid 1 size 1.81TB used 591.14GB path /dev/sde2
*** Some devices missing
Btrfs Btrfs v0.19
# btrfs filesystem df /mnt/btr Data, RAID0: total=64.00GB, used=31.90GB Data: total=63.01GB, used=61.67GB System, DUP: total=8.00MB, used=20.00KB System: total=4.00MB, used=0.00 Metadata, RAID1: total=128.00MB, used=104.71MB Metadata, DUP: total=1.00GB, used=6.15MB Metadata: total=8.00MB, used=0.00
# df -t btrfs Filesystem Type 1K-blocks Used Available Use% Mounted on /dev/sde btrfs 1992597264 98348716 1892087652 5% /mnt/btr
# -----------------------------------------
Look especially to "btrfs filesystem df /mnt/btr", it shows
Data, RAID0: total=64.00GB, used=31.90GB
Data: total=63.01GB, used=61.67GB
and that will lead to "no space left on device ...".
Viele Gruesse!
Helmut
Quoted 8 lines · Carl Cook
Quoted 7 lines · On Thu 20 January 2011 14:13:22 Goffredo Baroncelli wrote:
To add another disk you don't have to run mkfs.btrfs. For example:
# add the first disk mkfs.btrfs /dev/sdb # mount the disk mount /dev/sdb /media/backups
Quoted 6 lines
Quoted 2 lines
# add another disk to the first one btrfs device add /dev/sdc /media/backupThanks Goffredo but as I say, I did this and it responds with
"ERROR: error adding the device '/dev/sdc'"
.. it doesn't give a clue.
In your email you wrote that before adding the device you format it. Anyway I don't think that this is the problem.
Have you check which is reported in dmesg.
Quoted 10 lines
Quoted 8 lines
Note1: the filesystem has to be mounted
Note2: the medatada will be in raid1, the data in raid0 If you shutdown the system, at the reboot you should "scan" all the device in order to find the btrfs ones# find the btrfs device btrfs device scanThis must be done at every boot? If so, where is recommended, in rc.local?
Look at this thread, where I wrote anout a possible solution
http://www.mail-archive.com/[email protected]/msg04709.html
Quoted 6 lines
Quoted 5 lines
# if you try to mount snapshot-3 directly, you fail because this # snapshot is not under the root of the btrfs filesystem mount -o subvol=dir-1/snapshot-3 /dev/sdb /media/backup # -> error
Quoted 8 lines
This is how I'd understood it, but when creating a subvolume in the root and putting a snalshot into it, it seems to make a further subvolume (or directory) with a redundant name. This would not be under the root, and may not be mountable?
Quoted 1 line
Which kenel version debian testing uses ?
2.6.32-5-amd64 with Debian patches.
From a btrfs point of view, it is a very old kernel. IIRC in this kernel
is not supported the snapshot removal. I suggest you to update the kernel with a recent one.
Quoted 14 lines
Quoted 3 lines
btrfs filesystem snapshot / /snapshot-$(date +"%Y-%m-%d")
Oh thank you.
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.
Quoted 8 lines · On Fri 21 January 2011 10:42:39 Goffredo Baroncelli wrote:
Quoted 3 lines
Thanks Goffredo but as I say, I did this and it responds with
"ERROR: error adding the device '/dev/sdc'"
.. it doesn't give a clue.In your email you wrote that before adding the device you format it. Anyway I don't think that this is the problem.
Have you check which is reported in dmesg.
Absolutely no sign of a problem in dmesg or the logs.
Quoted 7 lines
Quoted 3 lines
Quoted 1 line
btrfs device scan
This must be done at every boot? If so, where is recommended, in rc.local?
Look at this thread, where I wrote anout a possible solution
Thanks. I am suspecting scan is built into Debian. Not sure what to look for though, with all the darned variables.
Quoted 5 lines
Quoted 1 line
2.6.32-5-amd64 with Debian patches.
From a btrfs point of view, it is a very old kernel. IIRC in this kernel is not supported the snapshot removal. I suggest you to update the kernel with a recent one.
I've looked for a newer kernel sources, but there isn't one with Debian patches. I always compile my kernel.