Re: [LEDE-DEV] [RFC 3/3] config: ext4: use 1K blocks by default to support online resize2fs
On 10/17/2016 11:25 PM, Michael Heimpold wrote: > In general, I'm fine with larger default partition size. However, this results > in large images available for download at downloads.lede-project.org... > > mhei Not necessarily, if the disk image filesystem's free space is zeroed (a guide here) http://unix.stackexchange.com/questions/44234/clear-unused-space-with-zeros-ext3-ext4 any half-decent compression algorithm (like gzip but also 7z) will shrink it down to the actual used size. Zeroing free space is needed also to shrink Virtualbox VMs virtual disks and similar. -Alberto ___ Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev
Re: [LEDE-DEV] [RFC 3/3] config: ext4: use 1K blocks by default to support online resize2fs
Hi, Am Montag, 17. Oktober 2016, 22:08:06 CEST schrieb Jo-Philipp Wich: > Hi Michael, > > > I can't see why adjusting the default partition size would have been > > necessary > > as genext2fs takes (or better: took) the following parameters: > The filesystem is generated okay but due to the total size : blocksize ratio > there are not enough backup block group descriptor entries left to support > online-resizing the rootfs partition, see > http://lists.infradead.org/pipermail/lede-dev/2016-September/002518.html > for a report that describes the problem. I understand the problem and solving this issue would be a great benefit. > I am fine with keeping 4k blocks but in this case we should increase the > default image size to at least the minimum value being able to support > resizing. The report mentions that 512M already work which would allow > resizing up to 512GB (1024 times larger). > > Sorry, but I can only find the default value of 48 MB? Do I miss > > something? > > See > https://git.lede-project.org/?p=source.git;a=blob;f=config/Config-images.in > #l263 > > I don't like reverting to 1k because when you use the image on a real > > device, e.g. eMMC or SD card, then usually the internal blocksize is 4k, > > and internal erase block size is often even 4 MiB. > > Thus using 1k blocksize is not optimal when using a writeable filesystem. > > I understand. As mentioned above, 4K blocks are fine for me too, but in this > case I suggest to bump the rootfs part size to 2GB which would support 2TB > rootfs partitions. > In general, I'm fine with larger default partition size. However, this results in large images available for download at downloads.lede-project.org... mhei ___ Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev
Re: [LEDE-DEV] [RFC 3/3] config: ext4: use 1K blocks by default to support online resize2fs
Hi Michael, > I can't see why adjusting the default partition size would have been necessary > as genext2fs takes (or better: took) the following parameters: The filesystem is generated okay but due to the total size : blocksize ratio there are not enough backup block group descriptor entries left to support online-resizing the rootfs partition, see http://lists.infradead.org/pipermail/lede-dev/2016-September/002518.html for a report that describes the problem. I am fine with keeping 4k blocks but in this case we should increase the default image size to at least the minimum value being able to support resizing. The report mentions that 512M already work which would allow resizing up to 512GB (1024 times larger). > Sorry, but I can only find the default value of 48 MB? Do I miss something? See https://git.lede-project.org/?p=source.git;a=blob;f=config/Config-images.in#l263 > I don't like reverting to 1k because when you use the image on a real > device, e.g. eMMC or SD card, then usually the internal blocksize is 4k, > and internal erase block size is often even 4 MiB. > Thus using 1k blocksize is not optimal when using a writeable filesystem. I understand. As mentioned above, 4K blocks are fine for me too, but in this case I suggest to bump the rootfs part size to 2GB which would support 2TB rootfs partitions. ~ Jo ___ Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev
Re: [LEDE-DEV] [RFC 3/3] config: ext4: use 1K blocks by default to support online resize2fs
Hi, Am Sonntag, 16. Oktober 2016, 01:59:44 CEST schrieb Jo-Philipp Wich: > Commit fe20272ab16068765a191f3a846f30f977bc7669 (SVN r40924) introduced > support for specifying ext4 blocksizes but silently switched the implicit > 1K value to 4K by default without also adjusting the default partition size. I can't see why adjusting the default partition size would have been necessary as genext2fs takes (or better: took) the following parameters: -B, --block-size -b, --size-in-blocks The commit introduced -B and adjusted -b accordingly, but did not touch the partition size at all. Image sizes were the same before and after, only block size default changed (silently, yes :-/ ). > > The current default size of 256MB Sorry, but I can only find the default value of 48 MB? Do I miss something? > in conjunction with 4K blocks produces an > ext4 filesystem which lacks the appropriate amount of backup GDT entries to > support online-resizing. > > Revert the 4K blocksize to 1K but keep the 256MB default size - this will > allow online resizing to a maximum of 256GB which should be sufficient > for now. I don't like reverting to 1k because when you use the image on a real device, e.g. eMMC or SD card, then usually the internal blocksize is 4k, and internal erase block size is often even 4 MiB. Thus using 1k blocksize is not optimal when using a writeable filesystem. Regards, Michael > > To support online resizing beyond 256GB we would need to enlarge the default > size to something like 2GB which would allow the FS to grow up to 2TB which > is the current theoretical LEDE limit due to the lack of GPT support on the > boot disk. > > Signed-off-by: Jo-Philipp Wich > --- > config/Config-images.in | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/config/Config-images.in b/config/Config-images.in > index 7d38341..6dfb3d1 100644 > --- a/config/Config-images.in > +++ b/config/Config-images.in > @@ -88,7 +88,7 @@ menu "Target Images" > > choice > prompt "Root filesystem block size" > - default TARGET_EXT4_BLOCKSIZE_4K > + default TARGET_EXT4_BLOCKSIZE_1K > depends on TARGET_ROOTFS_EXT4FS > help > Select the block size of the root filesystem. ___ Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev
