[LU-6152] zfs large block support

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.8.0
• Labels: llnl patch zfs
• Assignee: Nathaniel Clark
• Reporter: Minh Diep

Description

upstream zfs is about to land large block support (> 128k). see https://github.com/zfsonlinux/zfs/pull/2865

Lustre need to change to be able to compile with zfs.

Issue Links

• is related to: LU-6038 ZFS 0.6.4 Compatibility
• is related to: LU-4865 osd-zfs: increase object block size dynamically as object grows

Comments

[Rick Wagner (Inactive)]

I believe I found the issue: spa_maxblocksize was not exported in spa_misc.c from ZFS. I've rebuilt ZFS and successfully mount a ZFS-backed MDT and OST. I'll drop an issue at the GitHub ZFS repo.

[Rick Wagner (Inactive)]

The config step did not detect spa_maxblocksize, so the LB_CHECK_COMPILE macro is failing. Next step is for me is to see if config and my build of ZFS are correct.

configure:26062: checking if zfs defines spa_maxblocksize
WARNING: "spa_maxblocksize" [/home/build/lustre-release/build/conftest.ko] undefined!
lb_cv_compile_spa_maxblocksize=yes

[Rick Wagner (Inactive)]

A diff of the currents state of my source tree and the configure and build commands. I'm going to look at the LB_CHECK_COMPILE macro.

$ ./configure --with-zfs=/usr/src/zfs-0.6.3 --with-spl=/usr/src/spl-0.6.3 --with-linux=/usr/src/linux-3.10 --without-ldiskfs  --with-linux-config=/boot/config-3.10.65 
$ make rpms

[Rick Wagner (Inactive)]

Confirmed. After successfully mounting a ZFS-backed MDT, attempting to mount a ZFS-backed OST gives the following error and related dmesg output

[root@seahorse-oss-19-2 ~]# mount -t lustre ost0/ost0 /mnt/ost0
mount.lustre: mount ost0/ost0 at /mnt/ost0 failed: No such device
Are the lustre modules loaded?
Check /etc/modprobe.conf and /proc/filesystems

osd_zfs: Unknown symbol spa_maxblocksize (err 0)
osd_zfs: Unknown symbol spa_maxblocksize (err 0)
LustreError: 158-c: Can't load module 'osd-zfs'
LustreError: Skipped 1 previous similar message
LustreError: 15813:0:(genops.c:312:class_newdev()) OBD: unknown type: osd-zfs
LustreError: 15813:0:(genops.c:312:class_newdev()) Skipped 1 previous similar message
LustreError: 15813:0:(obd_config.c:369:class_attach()) Cannot create device ddragon-OST0000-osd of type osd-zfs : -19
LustreError: 15813:0:(obd_config.c:369:class_attach()) Skipped 1 previous similar message
LustreError: 15813:0:(obd_mount.c:199:lustre_start_simple()) ddragon-OST0000-osd attach error -19
LustreError: 15813:0:(obd_mount.c:199:lustre_start_simple()) Skipped 1 previous similar message
LustreError: 15813:0:(obd_mount_server.c:1750:server_fill_super()) Unable to start osd on ost0/ost0: -19
LustreError: 15813:0:(obd_mount_server.c:1750:server_fill_super()) Skipped 1 previous similar message
LustreError: 15813:0:(obd_mount.c:1340:lustre_fill_super()) Unable to mount  (-19)
LustreError: 15813:0:(obd_mount.c:1340:lustre_fill_super()) Skipped 1 previous similar message

[Rick Wagner (Inactive)]

When installing RPMs built with patch and linked against the ZFS on Linux master built with the [large block patch https://github.com/zfsonlinux/zfs/pull/2865], I'm receiving the following warning. I have not tested the Lustre build, but I'm suspicious that I'm about to see errors.

  Installing : lustre-osd-zfs-2.6.92-3.10.65_g98c5043.x86_64
WARNING: /lib/modules/3.10.65/extra/kernel/fs/lustre/osd_zfs.ko needs unknown symbol spa_maxblocksize

[Gerrit Updater]

Brian Behlendorf ([e-mail]) uploaded a new patch: http://review.whamcloud.com/13544
Subject: LU-6152 osd-zfs: ZFS large block compat
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: f5bab98f77036493bd96c2b05a19247d15fab328