Re: Please help me resize my ext4 file system to size > 16TB
On Tue, 13 Jun 2017, R. Ramesh wrote: > >That would be organizing your videos into N subdirectories and using new > >filesystems for some of those. Each single filesystem will be smaller > >than 16TB. > > > >If that works with your use case, you could do that now. > > Thanks. In that case, is mke2fs -O 64bit is enough? Or do I need a bunch of > other options to go with it like extent, extra_isize, etc. Can you tell me > why xfs is better? Is it as stable as ext4? Will I be able to add dmcache or > something similar as I create the new fs with xfs? If you plan things so that *each* one of these filesystems will be smaller than 16TB, plain mke2fs -t ext4 on your current system will do. That's why I pointed it out as a solution you could use *now*... OTOH, we will release the next Debian stable in about a week, and that one supports ext4 >16TB out-of-the-box. It is *still* risky to convert+resize an existing filesystem, of course. NOTE: while Debian Stretch (the next stable) will autodetect it needs 64-bit mode when creating >16TB ext4 filesystems, if you want to create a smaller one that could *grow* to >16TB, you likely have to specify "-O 64bit" manually. As for XFS, it is just as stable as ext4. And the two of them are far more stable than any of the other filesystems we support. Where I *always* recommend to use a plain, *small* ext4 and _not_ XFS is for /boot, because of the bootloader. XFS has been designed for extremely large enterprise arrays, and has supported very large singe filesystems and 64-bit everything for a lot longer than ext4: were you using it, AFAIK your filesystem would have been able to grow to >16TB in your current system. OTOH, you cannot *shrink* a XFS filesystem, while ext4 can be shrunk (backups required, of course). For multi-stream video, XFS works very well, but so does ext4. And you won't be doing heavily multi-threaded enterprise-IO on a DVR... XFS is a bit more averse to power cuts/hangs/crashes than ext4. It won't corrupt the *filesystem* (modulo kernel bug, bad RAM, or bad HDD), but if you were writing to a file, chances are that specific file will end up full of zeroes more likely than in ext4. If trouble does happen, ext4 fsck is considered best-in-class. The one for xfs (xfs_repair) is quite good, but not as comprehensive. dmcache is not that safe. That said, while I don't know why you'd need it, nowadays (as in: on an up-to-date stable/longterm kernel) it should work the same with ext4 and XFS. If in doubt, keep using ext4. > I have about 14TB over 4 disks. I will backup on to them and recreate > a newfs and copy them back. I do not like the downtime as that means > my DVR does not work for 4 days, at least, as copying will have to be > over usb3. If you want to use a *single* >16TB new filesystem on your _current_ system, you will have to use XFS. Hint: don't mess with mkfs.xfs options, it almost always does a better job when left to its autodetected defaults. If you want to use multiple filesystems on your _current_ system, pick the one you are already familiar with, and which is supported on your system: 32-bit ext4. If you are willing to wait a week and upgrade your system to the next Debian stable (in that case, backup the *entire* thing, should the updated system not work as a DVR to your liking), you will have the choice of XFS or 64-bit ext4. -- Henrique Holschuh
Re: Re: Please help me resize my ext4 file system to size > 16TB
> I am just looking for path of least resistance. That is why I asked if it That would be organizing your videos into N subdirectories and using new filesystems for some of those. Each single filesystem will be smaller than 16TB. If that works with your use case, you could do that now. Thanks. In that case, is mke2fs -O 64bit is enough? Or do I need a bunch of other options to go with it like extent, extra_isize, etc. Can you tell me why xfs is better? Is it as stable as ext4? Will I be able to add dmcache or something similar as I create the new fs with xfs? I have about 14TB over 4 disks. I will backup on to them and recreate a newfs and copy them back. I do not like the downtime as that means my DVR does not work for 4 days, at least, as copying will have to be over usb3. Ramesh
Re: Please help me resize my ext4 file system to size > 16TB
On 06/13/2017 10:48 AM, Doug wrote: On 06/12/2017 11:33 PM, R. Ramesh wrote: You implied you don't even have a backup of that data, which means you have exactly one chance of getting it right. This is a non-starter. First: you are warned to NEVER proceed with a filesystem resize before you have a valid, current, and *tested* backup. You are also warned that the ext4 *conversion* to 64-bit block numbers so as to be able to span more than 16TB is NOT your typical filesystem resize operation in the first place. It touches a *lot more* of the filesystem and the risks are much higher than just adding an extent. Even if it works flawlessly, it is not going to result in an optimal filesystem. The recommended procedure is to create a *new* filesystem and restore from backup (or copy from the legacy filesystem if you find a way to have both at the same time). And for such large filesystems, the use of "xfs" instead of "ext4" should be seriously considered. Second: whatever reasons you had, or excuses you gave yourself, nothing is going to get your data back if the filesystem ends up damaged beyond repair and you don't have a backup. "it would require updates that I am not ready do to yet"? Then DON'T. Find another way to solve your immediate problem, and postpone the larger filesystem for when you update everything. You *have* been warned. Now, you did not give us any idea of what is in that filesystem and what you use it for, but as an alternative to resizing it, maybe you could create several extra filesystems instead of enlarging the one you have and attaching these extra ones to wherever you need more space? Any subdirectory can be made an entirely separate filesystem... This wouldn't work for everything (e.g. you can't hardlink or fast-rename across filesystems), but maybe it would work for whatever you use that big filesystem for? -- Henrique Holschuh Henrique, Let us not worry about backup. The data is just videos and not worth the effort. They are all recreatable with some effort. So, it is ok to try resize2fs and if that dies, I will simply get the data from my DVDs/Blurays. I don't think there is in place ext4 to xfs conversion. So, converting to xfs is less possible that resize2fs. I am just looking for path of least resistance. That is why I asked if it possible to resize without any upgrade. I will eventually upgrade and eventually figure out something. I just need to hear that there isn't a simple solution I have overlooked *today*. That is all. Ramesh It would seem to me that the simplest way to solve this problem would be to buy a second drive that is big enough, format it with xfs, and copy everything you want to keep onto the new drive. Then when everything is done to your satisfaction, you can keep the original drive as a backup, or if you really don't care about backups, reformat the original drive and then use it, for whatever you want. (Make sure you copy the boot setup onto the new drive!) --doug Thanks. I have to spend at least $500 to get 12+TB disk. Not a good solution. I will wait it out till a stable resize2fs appears. Ramesh
Re: Please help me resize my ext4 file system to size > 16TB
On 06/12/2017 11:33 PM, R. Ramesh wrote: You implied you don't even have a backup of that data, which means you have exactly one chance of getting it right. This is a non-starter. First: you are warned to NEVER proceed with a filesystem resize before you have a valid, current, and *tested* backup. You are also warned that the ext4 *conversion* to 64-bit block numbers so as to be able to span more than 16TB is NOT your typical filesystem resize operation in the first place. It touches a *lot more* of the filesystem and the risks are much higher than just adding an extent. Even if it works flawlessly, it is not going to result in an optimal filesystem. The recommended procedure is to create a *new* filesystem and restore from backup (or copy from the legacy filesystem if you find a way to have both at the same time). And for such large filesystems, the use of "xfs" instead of "ext4" should be seriously considered. Second: whatever reasons you had, or excuses you gave yourself, nothing is going to get your data back if the filesystem ends up damaged beyond repair and you don't have a backup. "it would require updates that I am not ready do to yet"? Then DON'T. Find another way to solve your immediate problem, and postpone the larger filesystem for when you update everything. You *have* been warned. Now, you did not give us any idea of what is in that filesystem and what you use it for, but as an alternative to resizing it, maybe you could create several extra filesystems instead of enlarging the one you have and attaching these extra ones to wherever you need more space? Any subdirectory can be made an entirely separate filesystem... This wouldn't work for everything (e.g. you can't hardlink or fast-rename across filesystems), but maybe it would work for whatever you use that big filesystem for? -- Henrique Holschuh Henrique, Let us not worry about backup. The data is just videos and not worth the effort. They are all recreatable with some effort. So, it is ok to try resize2fs and if that dies, I will simply get the data from my DVDs/Blurays. I don't think there is in place ext4 to xfs conversion. So, converting to xfs is less possible that resize2fs. I am just looking for path of least resistance. That is why I asked if it possible to resize without any upgrade. I will eventually upgrade and eventually figure out something. I just need to hear that there isn't a simple solution I have overlooked *today*. That is all. Ramesh It would seem to me that the simplest way to solve this problem would be to buy a second drive that is big enough, format it with xfs, and copy everything you want to keep onto the new drive. Then when everything is done to your satisfaction, you can keep the original drive as a backup, or if you really don't care about backups, reformat the original drive and then use it, for whatever you want. (Make sure you copy the boot setup onto the new drive!) --doug
Re: Please help me resize my ext4 file system to size > 16TB
On Mon, 12 Jun 2017, R. Ramesh wrote: > >You implied you don't even have a backup of that data, which means you > >have exactly one chance of getting it right. This is a non-starter. ... > Let us not worry about backup. The data is just videos and not worth the > effort. They are all recreatable with some effort. So, it is ok to try Ok... > I am just looking for path of least resistance. That is why I asked if it That would be organizing your videos into N subdirectories and using new filesystems for some of those. Each single filesystem will be smaller than 16TB. If that works with your use case, you could do that now. > possible to resize without any upgrade. I will eventually upgrade and > eventually figure out something. I just need to hear that there isn't a > simple solution I have overlooked *today*. That is all. There are two that I know of, and the safe one is using several filesystems and mounting them normally as subdirectories. The other one would be using an overlay filesystem, but the very large size you need *is* going to get in the way of that. -- Henrique Holschuh
Re: Re: Please help me resize my ext4 file system to size > 16TB
You implied you don't even have a backup of that data, which means you have exactly one chance of getting it right. This is a non-starter. First: you are warned to NEVER proceed with a filesystem resize before you have a valid, current, and *tested* backup. You are also warned that the ext4 *conversion* to 64-bit block numbers so as to be able to span more than 16TB is NOT your typical filesystem resize operation in the first place. It touches a *lot more* of the filesystem and the risks are much higher than just adding an extent. Even if it works flawlessly, it is not going to result in an optimal filesystem. The recommended procedure is to create a *new* filesystem and restore from backup (or copy from the legacy filesystem if you find a way to have both at the same time). And for such large filesystems, the use of "xfs" instead of "ext4" should be seriously considered. Second: whatever reasons you had, or excuses you gave yourself, nothing is going to get your data back if the filesystem ends up damaged beyond repair and you don't have a backup. "it would require updates that I am not ready do to yet"? Then DON'T. Find another way to solve your immediate problem, and postpone the larger filesystem for when you update everything. You *have* been warned. Now, you did not give us any idea of what is in that filesystem and what you use it for, but as an alternative to resizing it, maybe you could create several extra filesystems instead of enlarging the one you have and attaching these extra ones to wherever you need more space? Any subdirectory can be made an entirely separate filesystem... This wouldn't work for everything (e.g. you can't hardlink or fast-rename across filesystems), but maybe it would work for whatever you use that big filesystem for? -- Henrique Holschuh Henrique, Let us not worry about backup. The data is just videos and not worth the effort. They are all recreatable with some effort. So, it is ok to try resize2fs and if that dies, I will simply get the data from my DVDs/Blurays. I don't think there is in place ext4 to xfs conversion. So, converting to xfs is less possible that resize2fs. I am just looking for path of least resistance. That is why I asked if it possible to resize without any upgrade. I will eventually upgrade and eventually figure out something. I just need to hear that there isn't a simple solution I have overlooked *today*. That is all. Ramesh
Re: Please help me resize my ext4 file system to size > 16TB
On Mon, 12 Jun 2017, Ramasubramanian Ramesh wrote: > >I think you ran into this problem: > >http://blog.ronnyegner-consulting.de/2011/08/18/ext4-and-the-16-tb-limit-now-solved/ > > > >I know of no way to get resize2fs to work with partitions larger than > >16 TB, however in the blog post it's explained how to make mke2fs > >work with such sizes by editing /etc/mke2fs.conf. Not sure if this is > >an option for you though. > > I have no way of backing up 16TB to use mke2fs. There is a solution ( > https://askubuntu.com/questions/779754/how-do-i-resize-an-ext4-partition-beyond-the-16tb-limit), > but needs updates that I am not ready to do yet. So, I am checking if > there is something that I missed that will allow me to resize without > having to upgrade release/kernel/e2fsprogs and all of its friends. You implied you don't even have a backup of that data, which means you have exactly one chance of getting it right. This is a non-starter. First: you are warned to NEVER proceed with a filesystem resize before you have a valid, current, and *tested* backup. You are also warned that the ext4 *conversion* to 64-bit block numbers so as to be able to span more than 16TB is NOT your typical filesystem resize operation in the first place. It touches a *lot more* of the filesystem and the risks are much higher than just adding an extent. Even if it works flawlessly, it is not going to result in an optimal filesystem. The recommended procedure is to create a *new* filesystem and restore from backup (or copy from the legacy filesystem if you find a way to have both at the same time). And for such large filesystems, the use of "xfs" instead of "ext4" should be seriously considered. Second: whatever reasons you had, or excuses you gave yourself, nothing is going to get your data back if the filesystem ends up damaged beyond repair and you don't have a backup. "it would require updates that I am not ready do to yet"? Then DON'T. Find another way to solve your immediate problem, and postpone the larger filesystem for when you update everything. You *have* been warned. Now, you did not give us any idea of what is in that filesystem and what you use it for, but as an alternative to resizing it, maybe you could create several extra filesystems instead of enlarging the one you have and attaching these extra ones to wherever you need more space? Any subdirectory can be made an entirely separate filesystem... This wouldn't work for everything (e.g. you can't hardlink or fast-rename across filesystems), but maybe it would work for whatever you use that big filesystem for? -- Henrique Holschuh
Re: Re: Please help me resize my ext4 file system to size > 16TB
> Hi, > > I have kernel 3.13 and e2fsprog 1.42.9 (as part of mybuntu 14.04.5 LTS). > With this, is it possible to resize2fs my ext4 RAID6 /dev/md0 to 24TB (ie > >16TB)? If so, please help me get there. If not, please recommend the > upgrades needed to the setup before this can be done. So, far, my google > says I need to do "tune2fs -O extents,uninit_bg,dir_index /dev/md0" which I > already did and I still get the dreaded message "resize2fs: New size too > large to be expressed in 32 bits." > > There are mentions of a 64bit option for the ext4 file system. I can see how > this relates to the error message from resize2fs, but I do not know what I > should do to get that update done for my /dev/md0. Also all of the message > that I come across relating to 64bit option, only talk about how to > *create* a brand new file system with 64bit. None of them tell me how to > convert existing one. In fact, many of them scare me saying that it will be > unsupported in older kernels. I am not really sure if my kernel is too old > or not. Also, they talk about a switch -b for resize2fs that is not > supported in the version installed currently on my system/release. > > Pleas help me figure out the correct sequence of steps. What packages need > update, if current kernel/release is ok? Or, do I need to upgrade to a newer > release before this is possible? > > Thanks > Ramesh > I think you ran into this problem: http://blog.ronnyegner-consulting.de/2011/08/18/ext4-and-the-16-tb-limit-now-solved/ I know of no way to get resize2fs to work with partitions larger than 16 TB, however in the blog post it's explained how to make mke2fs work with such sizes by editing /etc/mke2fs.conf. Not sure if this is an option for you though. I have no way of backing up 16TB to use mke2fs. There is a solution ( https://askubuntu.com/questions/779754/how-do-i-resize-an-ext4-partition-beyond-the-16tb-limit ), but needs updates that I am not ready to do yet. So, I am checking if there is something that I missed that will allow me to resize without having to upgrade release/kernel/e2fsprogs and all of its friends. Ramesh
Re: Please help me resize my ext4 file system to size > 16TB
On Sun, Jun 11, 2017 at 05:01:36PM -0500, Ram Ramesh wrote: > Hi, > > I have kernel 3.13 and e2fsprog 1.42.9 (as part of mybuntu 14.04.5 LTS). > With this, is it possible to resize2fs my ext4 RAID6 /dev/md0 to 24TB (ie > >16TB)? If so, please help me get there. If not, please recommend the > upgrades needed to the setup before this can be done. So, far, my google > says I need to do "tune2fs -O extents,uninit_bg,dir_index /dev/md0" which I > already did and I still get the dreaded message "resize2fs: New size too > large to be expressed in 32 bits." > > There are mentions of a 64bit option for the ext4 file system. I can see how > this relates to the error message from resize2fs, but I do not know what I > should do to get that update done for my /dev/md0. Also all of the message > that I come across relating to 64bit option, only talk about how to > *create* a brand new file system with 64bit. None of them tell me how to > convert existing one. In fact, many of them scare me saying that it will be > unsupported in older kernels. I am not really sure if my kernel is too old > or not. Also, they talk about a switch -b for resize2fs that is not > supported in the version installed currently on my system/release. > > Pleas help me figure out the correct sequence of steps. What packages need > update, if current kernel/release is ok? Or, do I need to upgrade to a newer > release before this is possible? > > Thanks > Ramesh > I think you ran into this problem: http://blog.ronnyegner-consulting.de/2011/08/18/ext4-and-the-16-tb-limit-now-solved/ I know of no way to get resize2fs to work with partitions larger than 16 TB, however in the blog post it's explained how to make mke2fs work with such sizes by editing /etc/mke2fs.conf. Not sure if this is an option for you though. -- 4096R/1224DBD299A4F5F3 47BC 7DE8 3D46 2E8B ED18 AA86 1224 DBD2 99A4 F5F3 signature.asc Description: Digital signature
Please help me resize my ext4 file system to size > 16TB
Hi, I have kernel 3.13 and e2fsprog 1.42.9 (as part of mybuntu 14.04.5 LTS). With this, is it possible to resize2fs my ext4 RAID6 /dev/md0 to 24TB (ie >16TB)? If so, please help me get there. If not, please recommend the upgrades needed to the setup before this can be done. So, far, my google says I need to do "tune2fs -O extents,uninit_bg,dir_index /dev/md0" which I already did and I still get the dreaded message "resize2fs: New size too large to be expressed in 32 bits." There are mentions of a 64bit option for the ext4 file system. I can see how this relates to the error message from resize2fs, but I do not know what I should do to get that update done for my /dev/md0. Also all of the message that I come across relating to 64bit option, only talk about how to *create* a brand new file system with 64bit. None of them tell me how to convert existing one. In fact, many of them scare me saying that it will be unsupported in older kernels. I am not really sure if my kernel is too old or not. Also, they talk about a switch -b for resize2fs that is not supported in the version installed currently on my system/release. Pleas help me figure out the correct sequence of steps. What packages need update, if current kernel/release is ok? Or, do I need to upgrade to a newer release before this is possible? Thanks Ramesh
