Re: How to erase a RAID1 (+++)?
Alberto Bursi posted on Fri, 31 Aug 2018 14:54:46 + as excerpted: > I just keep around a USB drive with a full Linux system on it, to act as > "recovery". If the btrfs raid fails I boot into that and I can do > maintenance with a full graphical interface and internet access so I can > google things. I do very similar, except my "recovery boot" is my backup (with normally including for root two levels of backup/recovery available, three for some things). I've actually gone so far as to have /etc/fstab be a symlink to one of several files, depending on what version of root vs. the off-root filesystems I'm booting, with a set of modular files that get assembled by scripts to build the fstabs as appropriate. So updating fstab is a process of updating the modules, then running the scripts to create the actual fstabs, and after I update a root backup the last step is changing the symlink to point to the appropriate fstab for that backup, so it's correct if I end up booting from it. Meanwhile, each root, working and two backups, is its own set of two device partitions in btrfs raid1 mode. (One set of backups is on separate physical devices, covering the device death scenario, the other is on different partitions on the same, newer and larger pair of physical devices as the working set, so it won't cover device death but still covers fat-fingering, filesystem fubaring, bad upgrades, etc.) /boot is separate and there's four of those (working and three backups), one each on each device of the two physical pairs, with the bios able to point to any of the four. I run grub2, so once the bios loads that, I can interactively load kernels from any of the other three /boots and choose to boot any of the three roots. And I build my own kernels, with an initrd attached as an initramfs to each, and test that they boot. So selecting a kernel by definition selects its attached initramfs as well, meaning the initr*s are backed up and selected with the kernels. (As I said earlier it'd sure be nice to be able to do away with the initr*s again. I was actually thinking about testing that today, which was supposed to be a day off, but got called in to work, so the test will have to wait once again...) What's nice about all that is that just as you said, each recovery/backup is a snapshot of the working system at the time I took the backup, so it's not a limited recovery boot at all, it has the same access to tools, manpages, net, X/plasma, browsers, etc, that my normal system does, because it /is/ my normal system from whenever I took the backup. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman
Re: How to erase a RAID1 (+++)?
On 08/31/2018 04:54 PM, Alberto Bursi wrote: On 8/31/2018 8:53 AM, Pierre Couderc wrote: OK, I have understood the message... I was planning that as you said "semi-routinely", and I understand btrfs is not soon enough ready, and I am very very far to be a specialist as you are. So, I shall mount my RAID1 very standard, and I shall expect the disaster, hoping it does not occur Now, I shall try to absorb all that... Thank you very much ! I just keep around a USB drive with a full Linux system on it, to act as "recovery". If the btrfs raid fails I boot into that and I can do maintenance with a full graphical interface and internet access so I can google things. Of course on a home server you can't do that without some automation that will switch boot device after some amount of boot failures of the main OS. While if your server has BMC (lights-out management) you can switch boot device through that. -Alberto Thank you Alberto, yes,I have some other computers to react in case of failure.
Re: How to erase a RAID1 (+++)?
On 8/31/2018 8:53 AM, Pierre Couderc wrote: > > OK, I have understood the message... I was planning that as you said > "semi-routinely", and I understand btrfs is not soon enough ready, and > I am very very far to be a specialist as you are. > So, I shall mount my RAID1 very standard, and I shall expect the > disaster, hoping it does not occur > Now, I shall try to absorb all that... > > Thank you very much ! > I just keep around a USB drive with a full Linux system on it, to act as "recovery". If the btrfs raid fails I boot into that and I can do maintenance with a full graphical interface and internet access so I can google things. Of course on a home server you can't do that without some automation that will switch boot device after some amount of boot failures of the main OS. While if your server has BMC (lights-out management) you can switch boot device through that. -Alberto
Re: How to erase a RAID1 (+++)?
On 08/31/2018 04:29 AM, Duncan wrote: Chris Murphy posted on Thu, 30 Aug 2018 11:08:28 -0600 as excerpted: My purpose is a simple RAID1 main fs, with bootable flag on the 2 disks in prder to start in degraded mode Good luck with this. The Btrfs archives are full of various limitations of Btrfs raid1. There is no automatic degraded mount for Btrfs. And if you persistently ask for degraded mount, you run the risk of other problems if there's merely a delayed discovery of one of the devices. Once a Btrfs volume is degraded, it does not automatically resume normal operation just because the formerly missing device becomes available. So... this is flat out not suitable for use cases where you need unattended raid1 degraded boot. Agreeing in general and adding some detail... 1) Are you intending to use an initr*? I'm not sure the current status (I actually need to test again for myself), but at least in the past, booting a btrfs raid1 rootfs required an initr*, and I have and use one here, for that purpose alone (until switching to btrfs raid1 root, I went initr*-less, and would prefer that again, due to the complications of maintaining an initr*). The base problem is that with raid1 (or other forms of multi-device btrfs, but it happens to be raid1 that's in question for both you and I) the filesystem needs multiple devices to complete the filesystem and the kernel's root= parameter takes only one. When mounting after userspace is up, a btrfs device scan is normally run (often automatically by udev) before the mount, that lets btrfs in the kernel track what devices belong to what filesystems, so pointing to just one of the devices is enough because the kernel knows from that what filesystem is intended and can match up the others that go with it from the earlier scan. Now there's a btrfs mount option, device=/dev/*, that can be provided more than once for additional devices, that can /normally/ be used to tell the kernel what specific devices to use, bypassing the need for btrfs device scan, and in /theory/, passing that like other mount options in the kernel commandline via rootflags= /should/ "just work". But for reasons I as a btrfs user (not dev, and definitely not kernel or btrfs dev) don't fully understand, passing device= via rootflags= is, or at least was, broken, so properly mounting a multi-device btrfs required (and may still require) userspace, thus for a multi-device btrfs rootfs, an initr*. So direct-booting to a multi-device btrfs rootfs didn't normally work. It would if you passed rootflags=degraded (at least with a two-device raid1 so the one device passed in root= contained one copy of everything), but then it was unclear if the additional device was successfully added to the raid1 later, or not. And with no automatic sync and bringing back to undegraded status, it was a risk I didn't want to take. So unfortunately, initr* it was! But I originally tested that when I setup my own btrfs raid1 rootfs very long ago in kernel and btrfs terms, kernel 3.6 or so IIRC, and while I've not /seen/ anything definitive on-list to suggest rootflags=device= is unbroken now (I asked recently and got an affirmative reply, but I asked for clarification and I've not seen it, tho perhaps it's there and I've not read it yet), perhaps I missed it. And I've not retested lately, tho I really should as while I asked I guess the only real way to know is to try it for myself, and it'd definitely be nice to be direct-booting without having to bother with an initr*, again. 2) As both Chris and I alluded to, unlike say mdraid, btrfs doesn't (yet) have an automatic mechanism to re-sync and "undegrade" after having been mounted degraded,rw. A btrfs scrub can be run to re-sync raid1 chunks, but single chunks may have been added while in the degraded state as well, and those need a balance convert to raid1 mode, before the filesystem and data on it can be be considered reliably able to withstand device loss once again. In fact, while the problem has been fixed now, for quite awhile if the filesystem was mounted degraded,rw, you often had exactly that one mount to fix the problem, as new chunks would be written in single mode and after that the filesystem would refuse to mount writable,degraded, and would only let you mount degraded,ro, which would let you get data off it but not let you fix the problem. Word to the wise if you're planning on running stable-debian (which tend to be older) kernels, or even just trying to use them for recovery if you need to! (The fix was to have a mount check if at least one copy of all chunks were available and allow rw mounting if so, instead of simply assuming that any single-mode chunks at all meant some wouldn't be available on a multi-device filesystem with a device missing, thus forcing read-only mode only mounting, as it used to do.) 3) If a btrfs raid1 is mounted degraded,rw with one device missing, then mounted again degraded,rw, with a different device
Re: How to erase a RAID1 (+++)?
On 08/30/2018 07:08 PM, Chris Murphy wrote: On Thu, Aug 30, 2018 at 3:13 AM, Pierre Couderc wrote: Trying to install a RAID1 on a debian stretch, I made some mistake and got this, after installing on disk1 and trying to add second disk : root@server:~# fdisk -l Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x2a799300 Device Boot StartEndSectors Size Id Type /dev/sda1 * 2048 3907028991 3907026944 1.8T 83 Linux Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x9770f6fa Device Boot StartEndSectors Size Id Type /dev/sdb1 * 2048 3907029167 3907027120 1.8T 5 Extended Extended partition type is not a problem if you're using GRUB as the bootloader; other bootloaders may not like this. Strictly speaking the type code 0x05 is incorrect, GRUB ignores type code, as does the kernel. GRUB also ignores the active bit (boot flag). And : root@server:~# btrfs fi show Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed Total devices 2 FS bytes used 1.10GiB devid1 size 1.82TiB used 4.02GiB path /dev/sda1 devid2 size 1.00KiB used 0.00B path /dev/sdb1 That's odd; and I know you've moved on from this problem but I would have liked to see the super for /dev/sdb1 and also the installer log for what commands were used for partitioning, including mkfs and device add commands. For what it's worth, 'btrfs dev add' formats the device being added, it does not need to be formatted in advance, and also it resizes the file system properly. Thank you, in fact my system seems more and more broken, so I cannot go further.. For example, a simple df gives me an IO error. I prefer reinstall the whole. But to avoid the same problems, is there somewhere an howto "install a basic RAID1 btrfs debian stretch system" ? OK, I install strech on 1 disk and then how do I "format" and add the second disk ? My purpose is a simple RAID1 main fs, with bootable flag on the 2 disks in prder to start in degraded mode Good luck with this. The Btrfs archives are full of various limitations of Btrfs raid1. There is no automatic degraded mount for Btrfs. And if you persistently ask for degraded mount, you run the risk of other problems if there's merely a delayed discovery of one of the devices. Once a Btrfs volume is degraded, it does not automatically resume normal operation just because the formerly missing device becomes available. So... this is flat out not suitable for use cases where you need unattended raid1 degraded boot. Well, I understnad the lesson that there is no hope currently to boot a degraded system... Thank you very much
Re: How to erase a RAID1 (+++)?
Chris Murphy posted on Thu, 30 Aug 2018 11:08:28 -0600 as excerpted: >> My purpose is a simple RAID1 main fs, with bootable flag on the 2 disks >> in prder to start in degraded mode > > Good luck with this. The Btrfs archives are full of various limitations > of Btrfs raid1. There is no automatic degraded mount for Btrfs. And if > you persistently ask for degraded mount, you run the risk of other > problems if there's merely a delayed discovery of one of the devices. > Once a Btrfs volume is degraded, it does not automatically resume normal > operation just because the formerly missing device becomes available. > > So... this is flat out not suitable for use cases where you need > unattended raid1 degraded boot. Agreeing in general and adding some detail... 1) Are you intending to use an initr*? I'm not sure the current status (I actually need to test again for myself), but at least in the past, booting a btrfs raid1 rootfs required an initr*, and I have and use one here, for that purpose alone (until switching to btrfs raid1 root, I went initr*-less, and would prefer that again, due to the complications of maintaining an initr*). The base problem is that with raid1 (or other forms of multi-device btrfs, but it happens to be raid1 that's in question for both you and I) the filesystem needs multiple devices to complete the filesystem and the kernel's root= parameter takes only one. When mounting after userspace is up, a btrfs device scan is normally run (often automatically by udev) before the mount, that lets btrfs in the kernel track what devices belong to what filesystems, so pointing to just one of the devices is enough because the kernel knows from that what filesystem is intended and can match up the others that go with it from the earlier scan. Now there's a btrfs mount option, device=/dev/*, that can be provided more than once for additional devices, that can /normally/ be used to tell the kernel what specific devices to use, bypassing the need for btrfs device scan, and in /theory/, passing that like other mount options in the kernel commandline via rootflags= /should/ "just work". But for reasons I as a btrfs user (not dev, and definitely not kernel or btrfs dev) don't fully understand, passing device= via rootflags= is, or at least was, broken, so properly mounting a multi-device btrfs required (and may still require) userspace, thus for a multi-device btrfs rootfs, an initr*. So direct-booting to a multi-device btrfs rootfs didn't normally work. It would if you passed rootflags=degraded (at least with a two-device raid1 so the one device passed in root= contained one copy of everything), but then it was unclear if the additional device was successfully added to the raid1 later, or not. And with no automatic sync and bringing back to undegraded status, it was a risk I didn't want to take. So unfortunately, initr* it was! But I originally tested that when I setup my own btrfs raid1 rootfs very long ago in kernel and btrfs terms, kernel 3.6 or so IIRC, and while I've not /seen/ anything definitive on-list to suggest rootflags=device= is unbroken now (I asked recently and got an affirmative reply, but I asked for clarification and I've not seen it, tho perhaps it's there and I've not read it yet), perhaps I missed it. And I've not retested lately, tho I really should as while I asked I guess the only real way to know is to try it for myself, and it'd definitely be nice to be direct-booting without having to bother with an initr*, again. 2) As both Chris and I alluded to, unlike say mdraid, btrfs doesn't (yet) have an automatic mechanism to re-sync and "undegrade" after having been mounted degraded,rw. A btrfs scrub can be run to re-sync raid1 chunks, but single chunks may have been added while in the degraded state as well, and those need a balance convert to raid1 mode, before the filesystem and data on it can be be considered reliably able to withstand device loss once again. In fact, while the problem has been fixed now, for quite awhile if the filesystem was mounted degraded,rw, you often had exactly that one mount to fix the problem, as new chunks would be written in single mode and after that the filesystem would refuse to mount writable,degraded, and would only let you mount degraded,ro, which would let you get data off it but not let you fix the problem. Word to the wise if you're planning on running stable-debian (which tend to be older) kernels, or even just trying to use them for recovery if you need to! (The fix was to have a mount check if at least one copy of all chunks were available and allow rw mounting if so, instead of simply assuming that any single-mode chunks at all meant some wouldn't be available on a multi-device filesystem with a device missing, thus forcing read-only mode only mounting, as it used to do.) 3) If a btrfs raid1 is mounted degraded,rw with one device missing, then mounted again
Re: How to erase a RAID1 (+++)?
And also, I'll argue this might have been a btrfs-progs bug as well, depending on what version was used and the command. Both mkfs and dev add should not be able to add type code 0x05. At least libblkid correctly shows that it's 1KiB in size, so really Btrfs should not succeed at adding this device, it can't put any of the supers in the correct location. [chris@f28h ~]$ sudo fdisk -l /dev/loop0 Disk /dev/loop0: 1 GiB, 1073741824 bytes, 2097152 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x7e255cce Device Boot StartEnd Sectors Size Id Type /dev/loop0p12048 206847 204800 100M 83 Linux /dev/loop0p2 206848 411647 204800 100M 83 Linux /dev/loop0p3 411648 616447 204800 100M 83 Linux /dev/loop0p4 616448 821247 204800 100M 5 Extended /dev/loop0p5 618496 821247 202752 99M 83 Linux [chris@f28h ~]$ sudo kpartx -a /dev/loop0 [chris@f28h ~]$ lsblk NAMEMAJ:MIN RM SIZE RO TYPE MOUNTPOINT loop0 7:00 1G 0 loop ├─loop0p1 253:10 100M 0 part ├─loop0p2 253:20 100M 0 part ├─loop0p3 253:30 100M 0 part ├─loop0p4 253:40 1K 0 part └─loop0p5 253:5099M 0 part [chris@f28h ~]$ sudo mkfs.btrfs /dev/loop0p4 btrfs-progs v4.17.1 See http://btrfs.wiki.kernel.org for more information. probe of /dev/loop0p4 failed, cannot detect existing filesystem. ERROR: use the -f option to force overwrite of /dev/loop0p4 [chris@f28h ~]$ sudo mkfs.btrfs /dev/loop0p4 -f btrfs-progs v4.17.1 See http://btrfs.wiki.kernel.org for more information. ERROR: mount check: cannot open /dev/loop0p4: No such file or directory ERROR: cannot check mount status of /dev/loop0p4: No such file or directory [chris@f28h ~]$ I guess that's a good sign in this case? Chris Murphy
Re: How to erase a RAID1 (+++)?
On Thu, Aug 30, 2018 at 9:21 AM, Alberto Bursi wrote: > > On 8/30/2018 11:13 AM, Pierre Couderc wrote: >> Trying to install a RAID1 on a debian stretch, I made some mistake and >> got this, after installing on disk1 and trying to add second disk : >> >> >> root@server:~# fdisk -l >> Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors >> Units: sectors of 1 * 512 = 512 bytes >> Sector size (logical/physical): 512 bytes / 512 bytes >> I/O size (minimum/optimal): 512 bytes / 512 bytes >> Disklabel type: dos >> Disk identifier: 0x2a799300 >> >> Device Boot StartEndSectors Size Id Type >> /dev/sda1 * 2048 3907028991 3907026944 1.8T 83 Linux >> >> >> Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors >> Units: sectors of 1 * 512 = 512 bytes >> Sector size (logical/physical): 512 bytes / 512 bytes >> I/O size (minimum/optimal): 512 bytes / 512 bytes >> Disklabel type: dos >> Disk identifier: 0x9770f6fa >> >> Device Boot StartEndSectors Size Id Type >> /dev/sdb1 * 2048 3907029167 3907027120 1.8T 5 Extended >> >> >> And : >> >> root@server:~# btrfs fi show >> Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed >> Total devices 2 FS bytes used 1.10GiB >> devid1 size 1.82TiB used 4.02GiB path /dev/sda1 >> devid2 size 1.00KiB used 0.00B path /dev/sdb1 >> >> ... >> >> My purpose is a simple RAID1 main fs, with bootable flag on the 2 >> disks in prder to start in degraded mode >> How to get out ofr that...? >> >> Thnaks >> PC > > > sdb1 is an extended partition, you cannot format an extended partition. > > change sdb1 into primary partition or add a logical partition into it. Ahh you're correct. There is special treatment of 0x05, it's a logical container with the start address actually pointing to the address where the EBR is. And that EBR's first record contains the actual real extended partition information. So this represents two bugs in the installer: 1. If there's only one partition on a drive, it should be primary by default, not extended. 2. But if extended, it must point to an EBR, and the EBR must be created at that location. Obviously since there is no /dev/sdb2, this EBR is not present. -- Chris Murphy
Re: How to erase a RAID1 (+++)?
On Thu, Aug 30, 2018 at 3:13 AM, Pierre Couderc wrote: > Trying to install a RAID1 on a debian stretch, I made some mistake and got > this, after installing on disk1 and trying to add second disk : > > > root@server:~# fdisk -l > Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disklabel type: dos > Disk identifier: 0x2a799300 > > Device Boot StartEndSectors Size Id Type > /dev/sda1 * 2048 3907028991 3907026944 1.8T 83 Linux > > > Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disklabel type: dos > Disk identifier: 0x9770f6fa > > Device Boot StartEndSectors Size Id Type > /dev/sdb1 * 2048 3907029167 3907027120 1.8T 5 Extended Extended partition type is not a problem if you're using GRUB as the bootloader; other bootloaders may not like this. Strictly speaking the type code 0x05 is incorrect, GRUB ignores type code, as does the kernel. GRUB also ignores the active bit (boot flag). > > > And : > > root@server:~# btrfs fi show > Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed > Total devices 2 FS bytes used 1.10GiB > devid1 size 1.82TiB used 4.02GiB path /dev/sda1 > devid2 size 1.00KiB used 0.00B path /dev/sdb1 That's odd; and I know you've moved on from this problem but I would have liked to see the super for /dev/sdb1 and also the installer log for what commands were used for partitioning, including mkfs and device add commands. For what it's worth, 'btrfs dev add' formats the device being added, it does not need to be formatted in advance, and also it resizes the file system properly. > My purpose is a simple RAID1 main fs, with bootable flag on the 2 disks in > prder to start in degraded mode Good luck with this. The Btrfs archives are full of various limitations of Btrfs raid1. There is no automatic degraded mount for Btrfs. And if you persistently ask for degraded mount, you run the risk of other problems if there's merely a delayed discovery of one of the devices. Once a Btrfs volume is degraded, it does not automatically resume normal operation just because the formerly missing device becomes available. So... this is flat out not suitable for use cases where you need unattended raid1 degraded boot. -- Chris Murphy
Re: How to erase a RAID1 (+++)?
On 8/30/2018 11:13 AM, Pierre Couderc wrote: > Trying to install a RAID1 on a debian stretch, I made some mistake and > got this, after installing on disk1 and trying to add second disk : > > > root@server:~# fdisk -l > Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disklabel type: dos > Disk identifier: 0x2a799300 > > Device Boot Start End Sectors Size Id Type > /dev/sda1 * 2048 3907028991 3907026944 1.8T 83 Linux > > > Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disklabel type: dos > Disk identifier: 0x9770f6fa > > Device Boot Start End Sectors Size Id Type > /dev/sdb1 * 2048 3907029167 3907027120 1.8T 5 Extended > > > And : > > root@server:~# btrfs fi show > Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed > Total devices 2 FS bytes used 1.10GiB > devid 1 size 1.82TiB used 4.02GiB path /dev/sda1 > devid 2 size 1.00KiB used 0.00B path /dev/sdb1 > > ... > > My purpose is a simple RAID1 main fs, with bootable flag on the 2 > disks in prder to start in degraded mode > How to get out ofr that...? > > Thnaks > PC sdb1 is an extended partition, you cannot format an extended partition. change sdb1 into primary partition or add a logical partition into it. -Alberto
Re: How to erase a RAID1 (+++)?
On Thursday, 30 August 2018 12:01:55 CEST Pierre Couderc wrote: > > On 08/30/2018 11:35 AM, Qu Wenruo wrote: > > > > On 2018/8/30 下午5:13, Pierre Couderc wrote: > >> Trying to install a RAID1 on a debian stretch, I made some mistake and > >> got this, after installing on disk1 and trying to add second disk : > >> > >> > >> root@server:~# fdisk -l > >> Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors > >> Units: sectors of 1 * 512 = 512 bytes > >> Sector size (logical/physical): 512 bytes / 512 bytes > >> I/O size (minimum/optimal): 512 bytes / 512 bytes > >> Disklabel type: dos > >> Disk identifier: 0x2a799300 > >> > >> Device Boot StartEndSectors Size Id Type > >> /dev/sda1 * 2048 3907028991 3907026944 1.8T 83 Linux > >> > >> > >> Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors > >> Units: sectors of 1 * 512 = 512 bytes > >> Sector size (logical/physical): 512 bytes / 512 bytes > >> I/O size (minimum/optimal): 512 bytes / 512 bytes > >> Disklabel type: dos > >> Disk identifier: 0x9770f6fa > >> > >> Device Boot StartEndSectors Size Id Type > >> /dev/sdb1 * 2048 3907029167 3907027120 1.8T 5 Extended > >> > >> > >> And : > >> > >> root@server:~# btrfs fi show > >> Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed > >> Total devices 2 FS bytes used 1.10GiB > >> devid1 size 1.82TiB used 4.02GiB path /dev/sda1 > >> devid2 size 1.00KiB used 0.00B path /dev/sdb1 I think your problem is that sdb1 is a extended partition and not a primary one or you'll need to make a logical partition inside the extended partition and use that. -- Kai Stian Olstad
Re: How to erase a RAID1 (+++)?
On 2018/8/30 下午6:01, Pierre Couderc wrote: > > > On 08/30/2018 11:35 AM, Qu Wenruo wrote: >> >> On 2018/8/30 下午5:13, Pierre Couderc wrote: >>> Trying to install a RAID1 on a debian stretch, I made some mistake and >>> got this, after installing on disk1 and trying to add second disk : >>> >>> >>> root@server:~# fdisk -l >>> Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors >>> Units: sectors of 1 * 512 =12 bytes >>> Sector size (logical/physical): 512 bytes / 512 bytes >>> I/O size (minimum/optimal): 512 bytes / 512 bytes >>> Disklabel type: dos >>> Disk identifier: 0x2a799300 >>> >>> Device Boot Start End Sectors Size Id Type >>> /dev/sda1 * 2048 3907028991 3907026944 1.8T 83 Linux >>> >>> >>> Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors >>> Units: sectors of 1 * 512 =12 bytes >>> Sector size (logical/physical): 512 bytes / 512 bytes >>> I/O size (minimum/optimal): 512 bytes / 512 bytes >>> Disklabel type: dos >>> Disk identifier: 0x9770f6fa >>> >>> Device Boot Start End Sectors Size Id Type >>> /dev/sdb1 * 2048 3907029167 3907027120 1.8T 5 Extended >>> >>> >>> And : >>> >>> root@server:~# btrfs fi show >>> Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed >>> Total devices 2 FS bytes used 1.10GiB >>> devid 1 size 1.82TiB used 4.02GiB path /dev/sda1 >>> devid 2 size 1.00KiB used 0.00B path /dev/sdb1 >>> >>> ... >>> >>> My purpose is a simple RAID1 main fs, with bootable flag on the 2 disks >>> in prder to start in degraded mode >>> How to get out ofr that...? >> The 2nd device is indeed strange. >> >> Considering how old packages Debian tends to deliver, it should be some >> old btrfs-progs. >> >> You could just boot into the system and execute the following commands: >> >> # btrfs device remove 2 > This works fine. >> >> Then add a new real device to the fs >> >> # btrfs device add >> >> > Thnk you, this : > > btrfs device add /dev/sdb1 / > > seems to work but gives me the same : > > root@server:~# btrfs fi show > Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed > Total devices 2 FS bytes used 1.10GiB > devid 1 size 1.82TiB used 4.02GiB path /dev/sda1 > devid 2 size 1.00KiB used 0.00B path /dev/sdb1 > > So I need to "prepare" or format /dev/sdb before adding /dev/sdb1 > I have tried to format /dev/sdb and it works : What's the output of lsblk command? If it's 2T (1.8T) show in lsblk, then in above case you could fix it by resize that device by: # btrfs resize 2:max Thanks, Qu > root@server:~# btrfs fi show > Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed > Total devices 2 FS bytes used 1.10GiB > devid 1 size 1.82TiB used 4.02GiB path /dev/sda1 > devid 2 size 1.82TiB used 0.00B path /dev/sdb > > but I have no partition table and no booot flag for degraded mode > > > signature.asc Description: OpenPGP digital signature
Re: How to erase a RAID1 (+++)?
On 08/30/2018 11:35 AM, Qu Wenruo wrote: On 2018/8/30 下午5:13, Pierre Couderc wrote: Trying to install a RAID1 on a debian stretch, I made some mistake and got this, after installing on disk1 and trying to add second disk : root@server:~# fdisk -l Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x2a799300 Device Boot Start End Sectors Size Id Type /dev/sda1 * 2048 3907028991 3907026944 1.8T 83 Linux Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x9770f6fa Device Boot Start End Sectors Size Id Type /dev/sdb1 * 2048 3907029167 3907027120 1.8T 5 Extended And : root@server:~# btrfs fi show Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed Total devices 2 FS bytes used 1.10GiB devid 1 size 1.82TiB used 4.02GiB path /dev/sda1 devid 2 size 1.00KiB used 0.00B path /dev/sdb1 ... My purpose is a simple RAID1 main fs, with bootable flag on the 2 disks in prder to start in degraded mode How to get out ofr that...? The 2nd device is indeed strange. Considering how old packages Debian tends to deliver, it should be some old btrfs-progs. You could just boot into the system and execute the following commands: # btrfs device remove 2 This works fine. Then add a new real device to the fs # btrfs device add Thnk you, this : btrfs device add /dev/sdb1 / seems to work but gives me the same : root@server:~# btrfs fi show Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed Total devices 2 FS bytes used 1.10GiB devid 1 size 1.82TiB used 4.02GiB path /dev/sda1 devid 2 size 1.00KiB used 0.00B path /dev/sdb1 So I need to "prepare" or format /dev/sdb before adding /dev/sdb1 I have tried to format /dev/sdb and it works : root@server:~# btrfs fi show Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed Total devices 2 FS bytes used 1.10GiB devid1 size 1.82TiB used 4.02GiB path /dev/sda1 devid2 size 1.82TiB used 0.00B path /dev/sdb but I have no partition table and no booot flag for degraded mode
Re: How to erase a RAID1 (+++)?
On 2018/8/30 下午5:13, Pierre Couderc wrote: > Trying to install a RAID1 on a debian stretch, I made some mistake and > got this, after installing on disk1 and trying to add second disk : > > > root@server:~# fdisk -l > Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disklabel type: dos > Disk identifier: 0x2a799300 > > Device Boot Start End Sectors Size Id Type > /dev/sda1 * 2048 3907028991 3907026944 1.8T 83 Linux > > > Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disklabel type: dos > Disk identifier: 0x9770f6fa > > Device Boot Start End Sectors Size Id Type > /dev/sdb1 * 2048 3907029167 3907027120 1.8T 5 Extended > > > And : > > root@server:~# btrfs fi show > Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed > Total devices 2 FS bytes used 1.10GiB > devid 1 size 1.82TiB used 4.02GiB path /dev/sda1 > devid 2 size 1.00KiB used 0.00B path /dev/sdb1 > > ... > > My purpose is a simple RAID1 main fs, with bootable flag on the 2 disks > in prder to start in degraded mode > How to get out ofr that...? The 2nd device is indeed strange. Considering how old packages Debian tends to deliver, it should be some old btrfs-progs. You could just boot into the system and execute the following commands: # btrfs device remove 2 Then add a new real device to the fs # btrfs device add Then convert the fs to RAID1 # btrfs balance start -dconvert=RAID1 -mconvert=RAID1 Thanks, Qu > > Thnaks > PC signature.asc Description: OpenPGP digital signature
Re: How to erase a RAID1 (+++)?
Trying to install a RAID1 on a debian stretch, I made some mistake and got this, after installing on disk1 and trying to add second disk : root@server:~# fdisk -l Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x2a799300 Device Boot Start End Sectors Size Id Type /dev/sda1 * 2048 3907028991 3907026944 1.8T 83 Linux Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x9770f6fa Device Boot Start End Sectors Size Id Type /dev/sdb1 * 2048 3907029167 3907027120 1.8T 5 Extended And : root@server:~# btrfs fi show Label: none uuid: eed65d24-6501-4991-94bd-6c3baf2af1ed Total devices 2 FS bytes used 1.10GiB devid 1 size 1.82TiB used 4.02GiB path /dev/sda1 devid 2 size 1.00KiB used 0.00B path /dev/sdb1 ... My purpose is a simple RAID1 main fs, with bootable flag on the 2 disks in prder to start in degraded mode How to get out ofr that...? Thnaks PC
Re: How to erase a RAID1 ?
[Forgot to Cc the list] On 2018/8/29 下午10:04, Pierre Couderc wrote: > > On 08/29/2018 02:52 PM, Qu Wenruo wrote: >> >> On 2018/8/29 下午8:49, Pierre Couderc wrote: >>> I want to reinstall a RAID1 btrfs system (wchis is now under debian >>> stretch, and will be reinstalled in stretch). >> If you still want to use btrfs, just umount the original fs, and >> >> # mkfs.btrfs -f >> >> Then a completely new btrfs. >> > The problem is to "unmount" the RAID1 system.. If it's not the root fs, it could be unmount if there is no user reading/writing or has any opened file. > > I have not found how to do that. > > I have found a solution by reinstalling under debian, it now asks if > need to reformat thez btrfs disk... If it's root fs, either go booting from another device, or just let the installer (well, it's booting from memory/another device already) to re-format the fs. Thanks, Qu > signature.asc Description: OpenPGP digital signature
Re: How to erase a RAID1 ?
On 08/29/2018 02:52 PM, Qu Wenruo wrote: On 2018/8/29 下午8:49, Pierre Couderc wrote: I want to reinstall a RAID1 btrfs system (wchis is now under debian stretch, and will be reinstalled in stretch). If you still want to use btrfs, just umount the original fs, and # mkfs.btrfs -f The problem is to "unmount" the RAID1 system.. I have not found how to do that. I have found a solution by reinstalling under debian, it now asks if need to reformat thez btrfs disk...
Re: How to erase a RAID1 ?
On 2018/8/29 下午8:49, Pierre Couderc wrote: > I want to reinstall a RAID1 btrfs system (wchis is now under debian > stretch, and will be reinstalled in stretch). If you still want to use btrfs, just umount the original fs, and # mkfs.btrfs -f Then a completely new btrfs. > > How to correctly "erase" it ? Not truly hard erase it, but so that old > data does not appear... If not planing to use btrfs, umount the fs and then wipefs -fa Thanks, Qu > > It is not clear in the wiki. > > Thanks > > PC > signature.asc Description: OpenPGP digital signature
How to erase a RAID1 ?
I want to reinstall a RAID1 btrfs system (wchis is now under debian stretch, and will be reinstalled in stretch). How to correctly "erase" it ? Not truly hard erase it, but so that old data does not appear... It is not clear in the wiki. Thanks PC
