OpenZFS on Linux and FreeBSD
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Richard Yao bff32e0972 Implement database to workaround misreported physical sector sizes
This implements vdev_bdev_database_check(). It alters the detected
sector size of any device listed in a database of drives known to lie
about their physical sector sizes.

This is based on "6931570 Add flash devices' VID/PID to disk table to
advertising 4K physical sector size" from Open Solaris and on
sg_simple4.c from sg3_utils. About two dozen lines are taken from
sg_simple4.c, which is GPLv2 licensed. However, sg_simple4.c is
analogous to a Hello World program and is safe for us to use. We
requested that Douglas Gilbert, the author of sg_simple4.c, confirm that
this is the case. A cutdown version of his response is as follows:

```
I would consider a SCSI INQUIRY example using the Linux sg
driver interface (also written by me) as the equivalent of an
"hello world" program in C.
```

The database was created with the help of the freenode and ZFSOnLinux
communities.

Some notes:

1. The following drives both were confirmed to lie via reports in IRC
and they contain capacity information in their identifiers:

INTEL SSDSA2M080
INTEL SSDSA2M160
M4-CT256M4SSD2
WDC WD15EARS-00S
WDC WD15EARS-00Z
WDC WD20EARS-00M

The identifiers for different capacity models were extrapolated and
added under the assumption that those models also lie. Google was used
to verify that the extrapolated drive identifiers existed prior to their
inclusion.

2. The OCZ-VERTEX2 3.5 identifer applies to two drives that differ
solely in page size (and slightly in capacity). One uses 4096-byte pages
and the other uses 8192-byte pages. Both are set to use 8192-byte pages.
We could detect the page size by checking the capacity, but that would
unnecessarily complicate the code.

3. It is possible for updated drive firmware to correctly report the
sector size. There were reports of a few advanced format drives doing
that. One report stated that the vendor changed the identification
string while another was unclear on this. Both reports involved WDC
models.

4. Google was used to determine the size of pages in the listed flash
devices. Reports of 8192-byte pages took precedence over reports of
4096-byte pages.

5. Devices behind USB adapters can have their identification strings
altered. Identification strings obtained across USB adapters are
omitted and no attempt is made to correct for alterations made by USB
adapters when doing comparisons against the database. Two entries in the
Open Solaris database that appear to have been altered by a USB
adapter were omitted.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1652
2013-08-22 11:24:06 -07:00
cmd Implement database to workaround misreported physical sector sizes 2013-08-22 11:24:06 -07:00
config Linux 3.11 compat: fops->iterate() 2013-08-15 16:19:07 -07:00
dracut Refresh dracut module setup 2013-03-21 12:51:06 -07:00
etc Improve OpenRC init script 2013-06-18 17:03:25 -07:00
include Linux 3.11 compat: fops->iterate() 2013-08-15 16:19:07 -07:00
lib No point in rewind() mtab in zfs_unshare_proto(). We're not really 2013-08-15 10:18:31 -07:00
man Fix man page for the sync property 2013-08-07 16:10:21 -07:00
module Linux 3.11 compat: fops->iterate() 2013-08-15 16:19:07 -07:00
patches Adding grub2 mkconfig support patch 2012-07-30 16:17:23 -07:00
rpm Add kmod repo integration 2013-08-01 09:48:07 -07:00
scripts Add kmod repo integration 2013-08-01 09:48:07 -07:00
udev Open pools asynchronously after module load 2013-07-03 09:24:38 -07:00
.gitignore Ignore *.{deb,rpm,tar.gz} files in the top directory. 2013-04-24 16:18:59 -07:00
AUTHORS Fix minor typos and update marketing copy. 2013-03-21 12:51:06 -07:00
COPYRIGHT Refresh links to web site 2013-03-06 15:46:41 -08:00
DISCLAIMER Fix minor typos and update marketing copy. 2013-03-21 12:51:06 -07:00
META Tag zfs-0.6.1 2013-03-26 08:50:29 -07:00
Makefile.am build: do not call boilerplate ourself 2013-04-02 10:55:20 -07:00
OPENSOLARIS.LICENSE Add CDDL license file 2008-12-01 14:49:34 -08:00
README.markdown Fix minor typos and update marketing copy. 2013-03-21 12:51:06 -07:00
autogen.sh build: do not call boilerplate ourself 2013-04-02 10:55:20 -07:00
configure.ac Modified arcstat.py to run on linux 2013-06-18 15:43:15 -07:00
copy-builtin Consistent menuconfig name 2012-08-26 13:49:37 -07:00
zfs-script-config.sh.in Retire zpool_id infrastructure 2013-01-29 12:23:17 -08:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

README.markdown

Native ZFS for Linux!

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

ZFS on Linux, which is also known as ZoL, is currently feature complete. It includes fully functional and stable SPA, DMU, ZVOL, and ZPL layers.

Full documentation for installing ZoL on your favorite Linux distribution can be found at: http://zfsonlinux.org