Need to format twice /dev/ramX with reiserfs to be able to mount it ?

sebastien cabaniols
2006-06-17T17:15:52Z

Hello list,

I am trying to format with reiserfs a ramdrive /dev/ramX (I want to nfs export
it, so tmpfs is not an option and ext2/ext3 is not an option for other
reasons)

After formating is okay I can't mount it, but If I reformat it, I usually can
mount it. I have also tried after first formating to dump it to a file and to
loopback mount the file, this works: I am puzzled.

Here is the sample session:

opteron:/home/seb # mkreiserfs -q /dev/ram8
mkreiserfs 3.6.18 (2003 www.namesys.com)

opteron:/home/seb # mount /dev/ram8 /tmp/mountpoint/
mount: wrong fs type, bad option, bad superblock on /dev/ram8,
missing codepage or other error
In some cases useful info is found in syslog - try
dmesg | tail or so

opteron:/home/seb # mkreiserfs -q /dev/ram8
mkreiserfs 3.6.18 (2003 www.namesys.com)

opteron:/home/seb # mount /dev/ram8 /tmp/mountpoint/

opteron:/home/seb # df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 18G 4.1G 13G 24% /
tmpfs 1004M 12K 1004M 1% /dev/shm
/dev/sda2 79G 9.9G 65G 14% /home
/dev/sda6 18G 2.5G 15G 15% /sys2
/dev/sda7 18G 2.5G 15G 15% /sys3
/dev/sda8 18G 129M 17G 1% /sys4
athlon:/data 111G 103G 1.6G 99% /data
/dev/ram8 125M 33M 93M 26% /tmp/mountpoint
opteron:/home/seb #

The filesystem looks usable (I have copied data into it and used it... it
looks functionnal)

I tried on several configurations:

32bit kernel 2.6.13-15.10 from SUSE 10 on a centrino laptop.
64bit kernel 2.6.13-15.10 from SUSE 10 on an opteron box.
64bit kernel 2.6.16 from kernel.org on an EMT64 box.

and when mount fails, dmesg tells me the following:

ReiserFS: ram8: warning: sh-2011: read_super_block: can't find a reiserfs
filesystem on (dev ram8, block 16, size 4096)

ReiserFS: ram8: warning: sh-2021: reiserfs_fill_super: can not find reiserfs
on ram8
ReiserFS: ram8: found reiserfs format "3.6" with standard journal
ReiserFS: ram8: using ordered data mode
ReiserFS: ram8: journal params: device ram8, size 8192, journal first block
18, max trans len 1024, max batch 900, max commit age 30, max trans age 30
ReiserFS: ram8: checking transaction log (ram8)
ReiserFS: ram8: Using r5 hash to sort names
ReiserFS: ram8: warning: Created .reiserfs_priv on ram8 - reserved for xattr
storage.

Thanks for any suggestion/idea.