ReiserFS Mount Options

conv

Instructs 3.6 ReiserFS code to mount 3.5 filesystem, using 3.6 format for newly created objects. After this you cannot use it through 3.5 ReiserFS tools anymore.

Example:

mount -t reiserfs -o conv /dev/sdb1 /mnt/scsi-disk-b

dontpanic

Ignore IO errors during journal committing. Without this option ReiserFS will panic on IO errors.
Only available when reiserfs-raw is used. Not in the stock kernels.

Example:

mount -t reiserfs -o dontpanic /dev/sdb1 /cache/squid-cache-1

hash=rupasov|tea|r5|detect

Choose hash function ReiserFS will use to find files within directories. Long time ago ReiserFS had only one hash, so hash code was not marked in filesystem superblock. Then additional hashes became available so we had to put hash code into super block. Also, old hash was made notdefault. At that time there were already a number of filesystems with not set hash code in super block. So, mount option was created to make it possible to write proper hash value into super block. Relative merits of hash functions were subjected to discussions of great length on the ReiserFS mailing list. (Try this query.) A special page describes how to choose hash function. Roughly speaking:

rupasov is hash invented by Yury Yu. Rupasov <yura@yura.polnet.botik.ru>. It is fast and preserves locality, mapping lexicographically close file names to the close hash values. Never use it, as it has high probability of hash collisions.
tea is a Davis-Meyer function implemented by Jeremy Fitzhardinge <jeremy@zip.com.au>. It is hash permuting bits in the name thoroughly. It gets high randomness and, therefore, low probability of hash collision, but this costs performance. Use this if you got EHASHCOLLISION with r5 hash.
r5 is a modified version of rupasov hash. It is used by default and it is better to stick here until you have to support huge directories and unusual file-name patterns.
detect instructs mount to detect hash function in use by instance of filesystem being mounted and write this information into superblock. This is only useful on the first mount of old filesystem.

Example:

mount -t reiserfs -o hash=r5 /dev/sdb1 /mnt/scsi-disk-b

hashed_relocation

Tunes block allocator. This may give you performance improvements in some situations.

Example:

mount -t reiserfs -o hashed_relocation /dev/sdb1 /mnt/scsi-disk-b

no_unhashed_relocation

Tunes block allocator. This may give you performance improvements in some situations.

Example:

mount -t reiserfs -o no_unhashed_relocation /dev/sdb1 /mnt/scsi-disk-b

noborder

Disable `border allocator algorithm' invented by Yury Yu. Rupasov <yura@yura.polnet.botik.ru>. This may give you performance improvements in some situations.

Example:

mount -t reiserfs -o noborder /dev/sdb1 /mnt/scsi-disk-b

nolog

Disable journalling. This will get you slight performance improvement in some situations at the cost of losing fast recovery from crashes. Actually even with this option turned on, ReiserFS still performs all journalling paraphernalia, save for actual writes into journalling area. Implementation of real nolog is work in progress.

Example:

mount -t reiserfs -o nolog /dev/sdb1 /mnt/scsi-disk-b

notail

By default, ReiserFS stores small files and `file tails' directly into the tree. This confuses some utilities like LILO. This option is used to disable packing of files into the tree.

Example:

mount -t reiserfs -o notail /dev/sdb1 /mnt/scsi-disk-b

pgc=LOW,HIGH

Activate Passive Garbage Collector.
Only available when reiserfs-raw is used. Not in the stock kernels.

Example:

mount -t reiserfs -o pgc=50,75 /dev/sdb1 /cache/squid-cache-1

raw

Mount filesystem in `raw' access mode.
Only available when reiserfs-raw is used. Not in the stock kernels.

Example:

mount -t reiserfs -o raw /dev/sdb1 /cache/squid-cache-1

replayonly

Replay transactions in journal, but don't actually mount filesystem. Used by fsck, mostly.

Example:

mount -t reiserfs -o replayonly /dev/sdb1 /mnt/scsi-disk-b

resize=NUMBER

Remount option allowing to expand ReiserFS partition on-line. Make ReiserFS think that device has NUMBER blocks. Useful with LVM devices. There is a special resizer utility which can be obtained from ftp://ftp.namesys.com/pub/reiserfsprogs

Example:

mount -t reiserfs -o resize=680000 /dev/sdb1 /mnt/scsi-disk-b

Maintainer: Danilov Nikita