[lustre-discuss] Lustre-2.15.X with ldiskfs cannot mount MGS/MDT

[Tung-Han Hsieh]

Dear All,

We manually compiled and installed Lustre-2.15.0 and 2.15.1,
with backend file system ldiskfs. We found that it cannot mount
the MGT/MDT partition at all (we formatted MGT and MDT in the
same partition).

The symptom is following. After installation, we partitioned and
formatted the Lustre file system using the following commands:

# mkfs.lustre --fsname ctest --mdt --mgs --index=0 /dev/sdb1
# mkfs.lustre --fsname ctest --ost --mgsnode=<host>@tcp0 --index=0 /dev/sdb2

Then trying to mount /dev/sdb1, we got the error message:

=========================================
# mount -t lustre /dev/sdb1
mount.lustre: /dev/sdb1 has not been formatted with mkfs.lustre or the backend filesystem type is not supported by this tool
=========================================

We further tried tunefs.lustre, and found that sdb2 seemed normal, but sdb1
failed:

=========================================
# tunefs.lustre /dev/sdb1
checking for existing Lustre data: not found

tunefs.lustre FATAL: Device /dev/sdb1 has not been formatted with mkfs.lustre
tunefs.lustre: exiting with 19 (No such device)

# /opt/lustre/sbin/tunefs.lustre /dev/sdb2
checking for existing Lustre data: found

   Read previous values:
Target:     ctest-OST0000
Index:      0
Lustre FS:  ctest
Mount type: ldiskfs
Flags:      0x2
              (OST )
Persistent mount opts: ,errors=remount-ro
Parameters: mgsnode=192.168.50.3 at tcp

   Permanent disk data:
Target:     ctest-OST0000
Index:      0
Lustre FS:  ctest
Mount type: ldiskfs
Flags:      0x2
              (OST )
Persistent mount opts: ,errors=remount-ro
Parameters: mgsnode=192.168.50.3 at tcp

Writing CONFIGS/mountdata
=========================================

Even if both partitions were pre-formatted and successfully mounted, stored
data by Lustre-2.12.6 with ldiskfs, the MGT/MDT partition still cannot be
mounted by Lustre-2.15.X.

On the other hand, there is no problem to mount MGT/MDT partition with
ldiskfs in Lustre-2.15.X. If the partition is newly formatted, there is
only CONFIG/mountdata with 12288 bytes. If it is pre-formatted and used
by previous Lustre version, it contains.

=========================================
BATCHID             lost+found/  oi.16.22  oi.16.4   oi.16.57
CATALOGS            lov_objid    oi.16.23  oi.16.40  oi.16.58
CONFIGS/            lov_objseq   oi.16.24  oi.16.41  oi.16.59
LFSCK/              nodemap      oi.16.25  oi.16.42  oi.16.6
NIDTBL_VERSIONS/    oi.16.0      oi.16.26  oi.16.43  oi.16.60
O/                  oi.16.1      oi.16.27  oi.16.44  oi.16.61
OI_scrub            oi.16.10     oi.16.28  oi.16.45  oi.16.62
PENDING/            oi.16.11     oi.16.29  oi.16.46  oi.16.63
REMOTE_PARENT_DIR/  oi.16.12     oi.16.3   oi.16.47  oi.16.7
ROOT/               oi.16.13     oi.16.30  oi.16.48  oi.16.8
changelog_catalog   oi.16.14     oi.16.31  oi.16.49  oi.16.9
changelog_users     oi.16.15     oi.16.32  oi.16.5   quota_master/
fld                 oi.16.16     oi.16.33  oi.16.50  quota_slave/
hsm_actions         oi.16.17     oi.16.34  oi.16.51  reply_data
index_backup/       oi.16.18     oi.16.35  oi.16.52  seq_ctl
last_rcvd           oi.16.19     oi.16.36  oi.16.53  seq_srv
lfsck_bookmark      oi.16.2      oi.16.37  oi.16.54  update_log
lfsck_layout        oi.16.20     oi.16.38  oi.16.55  update_log_dir/
lfsck_namespace     oi.16.21     oi.16.39  oi.16.56
=========================================

We manually compiled Lustre-2.15.X with the following steps:

1. Install vanilla Linux kernel kernel 5.4.135, because we saw:

   lustre-2.15.X/ldiskfs/kernel_patches/series/ldiskfs-5.4.136-ml.series

   The Linux kernel source was not patched by Lustre code.

2. In lustre-2.15.X source tree, we run:

   ./configure --prefix=/opt/lustre --with-linux=/usr/src/linux-5.4.135 \
               --with-o2ib=no --enable-mpitests=no
   make
   make install
   depmod -a 5.4.136
   export PATH="/opt/lustre/sbin:/opt/lustre/bin:$PATH"
   export LD_LIBRARY_PATH="/opt/lustre/lib:$LD_LIBRARY_PATH"
   ( cd /usr/sbin; ln -s /opt/lustre/sbin/ko2iblnd-probe . )
   ( cd /usr/sbin; ln -s /opt/lustre/sbin/l_getidentity . )
   ( cd /usr/sbin; ln -s /opt/lustre/sbin/l_tunedisk . )
   ( cd /usr/sbin; ln -s /opt/lustre/sbin/lctl . )

   The contents of /etc/modprobe.d/lustre.conf is:

   options lnet networks="tcp0(eth0)"

   During the compilation and installation, there is no errors.

3. We compiled and installed e2fsprogs-1.46.2.wc5.


Could anyone see how to solve this problem ? Thank you very much.

Best Regards,

T.H.Hsieh