OpenZFS on Linux and FreeBSD
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Prakash Surya 475ebd763a Fix device expansion when VM is powered off
When running on an ESXi based VM, I've found that "zpool online -e" will
not expand the zpool, if the disk was expanded in ESXi while the VM was
powered off.

For example, take the following scenario:

 1. VM running on top of VMware ESXi
 2. ZFS pool created with a given device "sda" of size 8GB
 3. VM powered off
 4. Device "sda" size expanded to 16GB
 5. VM powered on
 6. "zpool online -e" used on device "sda"

In this situation, after (2) the zpool will be roughly 8GB in size.
After (6), the expectation is the zpool's size will expand to roughly
16GB in size; i.e. expand to the new size of the "sda" device.
Unfortunately, I've seen that after (6), the zpool size does not change.

What's happening is after (5), the EFI label of the "sda" device will be
such that fields "efi_last_u_lba", "efi_last_lba", and "efi_altern_lba"
all reflect the new size of the disk; i.e. "33554398", "33554431", and
"33554431" respectively.

Thus, the check that we perform in "efi_use_whole_disk":

    if ((efi_label->efi_altern_lba == 1) || (efi_label->efi_altern_lba
        >= efi_label->efi_last_lba)) {

This will return true, and then we return from the function without
having expanded the size of the zpool/device.

In contrast, if we remove steps (3) and (5) in the sequence above, i.e.
the device is expanded while the VM is powered on, things change. In
that case, the fields "efi_last_u_lba" and "efi_altern_lba" do not
change (i.e. they still reflect the old 8GB device size), but the
"efi_last_lba" field does change (i.e. it now reflects the new 16GB
device size). Thus, when we evaluate the same conditional in
"efi_use_whole_disk", it'll return false, so the zpool is expanded.

Taking all of this into account, this PR updates "efi_use_whole_disk" to
properly expand the zpool when the underlying disk is expanded while the
VM is powered off.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes #9111
2019-08-13 21:18:53 -06:00
.github Update CONTRIBUTING to point users to IRC as well as mailing list 2019-03-13 11:57:57 -07:00
cmd spa_load_verify() may consume too much memory 2019-08-13 08:11:57 -06:00
config Minor style cleanup 2019-07-16 17:22:31 -07:00
contrib Add channel program for property based snapshots 2019-07-30 16:02:19 -07:00
etc Race between zfs-share and zfs-mount services 2019-07-28 18:13:56 -07:00
include spa_load_verify() may consume too much memory 2019-08-13 08:11:57 -06:00
lib Fix device expansion when VM is powered off 2019-08-13 21:18:53 -06:00
man spa_load_verify() may consume too much memory 2019-08-13 08:11:57 -06:00
module Mark dsl_livelist_should_disable() static 2019-08-13 21:16:23 -06:00
rpm install path fixes 2019-07-30 10:06:09 -07:00
scripts Fix out-of-tree build failures 2019-06-24 09:32:47 -07:00
tests Introduce getting holds and listing bookmarks through ZCP 2019-08-12 10:02:34 -07:00
udev Add enclosure_symlinks option to vdev_id 2018-12-14 17:27:49 -08:00
.gitignore git ignore python 3.7 virtual environment directories 2019-03-25 15:05:26 -07:00
.gitmodules Add zimport.sh compatibility test script 2014-02-21 12:10:31 -08:00
.travis.yml Add .travis.yml 2017-11-13 09:18:18 -08:00
AUTHORS Update build system and packaging 2018-05-29 16:00:33 -07:00
CODE_OF_CONDUCT.md Add CODE_OF_CONDUCT.md 2019-04-30 10:58:45 -07:00
COPYRIGHT Update build system and packaging 2018-05-29 16:00:33 -07:00
LICENSE Update build system and packaging 2018-05-29 16:00:33 -07:00
META Tag 0.8.0 2019-05-21 11:11:41 -07:00
Makefile.am Fix out-of-tree build failures 2019-06-24 09:32:47 -07:00
NEWS Add NEWS file 2018-09-18 12:03:47 -07:00
NOTICE Update build system and packaging 2018-05-29 16:00:33 -07:00
README.md Explicitly state supported Linux versions 2018-05-30 20:11:19 -07:00
TEST Update build system and packaging 2018-05-29 16:00:33 -07:00
autogen.sh Cause autogen.sh to fail if autoreconf fails 2018-07-06 09:27:37 -07:00
configure.ac Add channel program for property based snapshots 2019-07-30 16:02:19 -07:00
copy-builtin Allow copy-builtin to work with modified sources 2018-10-17 12:06:05 -07:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

README.md

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ZFS on Linux is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the OpenZFS community.

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Official Resources

Installation

Full documentation for installing ZoL on your favorite Linux distribution can be found at our site.

Contribute & Develop

We have a separate document with contribution guidelines.

Release

ZFS on Linux is released under a CDDL license.
For more details see the NOTICE, LICENSE and COPYRIGHT files; UCRL-CODE-235197

Supported Kernels

  • The META file contains the officially recognized supported kernel versions.