D.0 Comparison of NSS on NetWare and NSS on Linux

This section compares features and capabilities of Novell® Storage Services™ on the NetWare® and Linux platforms for OES.

Feature Description

NSS for OES NetWare and NetWare 6.5

NSS for OES Linux

Management interfaces

Novell iManager

Novell iManager

NSSMU for NetWare

NSSMU for Linux

EVMS (evmsgui)

Utilities in the server console (nssmu, rights, flag)

Utilities in the server console (nssmu, rights, nsscon, attrib, ravsui, ravview, nbackup)

Commands in the server console

Commands in the NSS Console (nsscon)

Novell Remote Manager for NetWare (primarily for trustee management, file and directory purge and salvage)

Novell Remote Manager for Linux (browse only)

Novell NetStorage

Novell NetStorage

ConsoleOne® (DFS junctions, VLDB, and file system trustees and trustee rights)

Not available (DFS junction support is not available for NSS on Linux.)

File system trustees and trustee rights to control access to directories and files

Novell Remote Manager for NetWare

Novell NetStorage (via Web browser only, not WebDAV)

Novell NetStorage (via Web browser only, not WebDAV)

Novell Client™. See Using the Novell Client to Manage Trustees and Trustee Rights in the File Systems Management Guide for OES .

Novell Client. Using the Novell Client to Manage Trustees and Trustee Rights in the File Systems Management Guide for OES .

Rights utility for NetWare. See Trustee Rights Utility for NetWare in the File Systems Management Guide for OES .

Rights utility for Linux. See Trustee Rights Utility for Linux in the File Systems Management Guide for OES .

ConsoleOne

File system directory and file attributes to control functions available for directories and files

Novell NetStorage

Novell Client (NCP™)

Rights Utility for Linux

Novell Remote Manager for NetWare. See Managing Attributes for Directories and Files in the File Systems Management Guide for OES .

ConsoleOne

Novell NetStorage

Novell Client (NCP)

Rights Utility for Linux

Novell Remote Manager for Linux. See Displaying Key NSS Directory and File Attributes as Linux POSIX Permissions in the File Systems Management Guide for OES

Directory quotas management (requires the Directory Quotas attribute for the volume)

Novell NetStorage

Novell Client

Novell Remote Manager for NetWare

Novell NetStorage

Novell Client

User space quota management (requires the User Space Quotas attribute for the volume )

Novell iManager

Novell iManager

Make sure to Linux-enable users with Linux User Management before you set the quota.

User space quotas are available in OES SP1 and later.

Default mount location for NSS pools

Not applicable

/opt/novell/nss/mnt/.pools/

Default mount location for NSS volumes

Server root

/media/nss/

Default mount location for devices managed by EVMS

Not applicable

/dev/evms/

File system type (as recognized and reported by the operating system)

nss

nssvol

File protocols

NCP

AFP, NFS, and CIFS

NCP

NFS and CIFS (Samba) require users to be Linux-enabled with Linux User Management.

AFP is available only through third-party software.

Interface

64-bit

64-bit

Character format

Unicode

Unicode

Maximum device size recognized (physical or logical)

2 TB

2 TB

Maximum partition size

2 TB

2 TB

Maximum number of partitions (logical or physical devices) per pool

No practical limit

A partition must have more than 10 MB and less than 2 TB of available space to be recognized by NSS.

No practical limit

A partition must have more than 10 MB and less than 2 TB of available space to be recognized by NSS.

Maximum pool size (using at least 4 partitions of up to 2 TB each)

8 TB

8 TB

Minimum pool size

10 MB

10 MB

Maximum size of a volume

Up to 8 TB, depending on the pool size and available space in the pool

Volume quotas can be overbooked. For information about overbooking, see Section 13.1, Understanding NSS Volumes. For information, see Section 18.2, Managing NSS Volume Quotas.

Up to 8 TB, depending on the pool size and available space in the pool

Volume quotas can be overbooked. For information about overbooking, see Section 13.1, Understanding NSS Volumes. For information, see Section 18.2, Managing NSS Volume Quotas.

Maximum file size

Up to 8 TB, depending on the volume size and available space in the volume

Up to 8 TB, depending on the volume size and available space in the volume

Maximum number of files per volume

Up to 8 trillion, regardless of how many name spaces are loaded

Up to 8 trillion, regardless of how many name spaces are loaded

Maximum number of files open concurrently

1 million

1 million

Maximum number of volumes per server

255 plus the sys: volume.

You can mount NSS volumes beyond 256, but they are not visable or accessible through the normal Netware APIs.

No practical limit on the number of NSS data volumes

Time to mount a volume

Requires only a few seconds

NSS uses a journaling file system and does not need to scan the entire file system to create a directory entry table (DET) and to load a File Allocation Table (FAT).

Requires only a few seconds

NSS uses a journaling file system and does not need to scan the entire file system to create a directory entry table (DET) and to load a File Allocation Table (FAT).

Volume name space

Accommodates all name spaces (DOS, Macintosh, Long, and UNIX).

In OES SP1 and later, you can use the Lookup Name Space attribute for the volume to specify the default name space to use when activating the volume.

Directory names and file names are case insensitive.

Accommodates all name spaces (DOS, Macintosh, Long, and UNIX).

In OES SP1 and later, you can use the Lookup Name Space attribute for the volume to specify the default name space to use when mounting the volume.

UNIX is the default name space, which is case sensitive. However, you can specify the Long name spaces on mounting the NSS volume to make its directory names and filenames case insensitive. For information, see Section 13.17, Mounting an NSS Volume on Linux to Support Case Insensitive File Names (Linux).

Minimum server memory required to activate a volume

Requires only 4 MB available RAM to activate a single volume of any size and any number of files. Loads a file’s metadata into memory only as you access the file.

Requires only 4 MB available RAM to activate a single volume of any size and any number of files. Loads a file’s metadata into memory only as you access the file.

File access time

Same for each file, regardless of its location on the volume.

Same for each file, regardless of its location on the volume.

Error correction and data recovery time on system failure

Journaling file system logs changes.

On system failure, replays the most recent transactions to confirm validity, then repairs errors or rolls back to the original condition, typically in 15 to 60 seconds, unless the volume is corrupted.

Journaling file system logs changes.

On system failure, replays the most recent transactions to confirm validity, then repairs errors or rolls back to the original condition, typically in 15 to 60 seconds, unless the volume is corrupted.

Repair of corrupted volume

Ongoing journaling of the file system; if corrupted, use verify and rebuild functions.

Ongoing journaling of the file system; if corrupted, use the ravsui utility to verify and rebuild the volume.

Time to repair corrupted volume

From a few seconds to several hours, depending on the volume size.

From a few seconds to several hours, depending on the volume size.

Multiple connection paths to storage media

Yes, NSS multipath I/O

NSS multipath I/O is not supported; use a Linux-based multiple path I/O solution.

Software RAID support

RAID 0 (striping)

RAID 1 (mirroring)

RAID 5 (striping with parity)

RAID 10 (mirroring RAID 0 devices)

RAID 15 (mirroring RAID 5 devices)

RAID 0 (striping)

RAID 1 (mirroring)

RAID 10 (mirroring RAID 0 devices)

For OES SP1 and later, the following additional software RAIDs are supported:

  • RAID 5 (striping with parity)

  • RAID 15 (mirroring RAID 5 devices)

Volume encryption

Yes

Yes, for OES SP1 and later

You must mount encrypted volumes only from NSSMU on the first mount after a system reboot so that you can enter the password. The nsscon utility does not support entering a password from the command line.

Data shredding

Yes, up to 7 times

Yes, up to 7 times

File compression

Yes

Yes

Data migration

Yes

Yes

Directory quotas

Yes

Yes

User space quotas (user space restrictions)

Yes

Yes, only for OES SP1 and later

Make sure to Linux-enable users with Linux User Management before you set the quota.

Salvage or purge deleted files, directories, or volumes

Yes

Yes

Transaction Tracking System™ (TTS™)

Yes

Not supported

Read ahead blocks

Yes

Yes

File save time

Offers the Flush Files Immediately attribute for NSS volumes to write files to disk on save instead of waiting for the next disk write cycle. This helps prevent possible data loss between disk write cycles.

Offers the Flush Files Immediately attribute for NSS volumes to write files to disk on save instead of waiting for the next disk write cycle. This helps prevent possible data loss between disk write cycles.

File-level snapshot

(make a temporary snapshot copy of an open file for backup)

Yes; allows back up of a copy of a file that is open nonexclusively so that it is not necessary to deactivate the volume for backup

Not supported

Pool snapshot

(retain point-in-time version of a pool using block-level copy on write)

Yes; allows backup of block-level changes only, without deactivating the volume.

Uses a brief freeze-release process to capture information for last remaining open files.

Not supported

Backup support

Reviews only a list of files modified since the previous backup

No APIs are available.

Backup systems support

Novell Storage Management Services

SBCONI

Novell Storage Management Services

nbackup(1) and related utilities. For links to man pages, see Section 25.1, Using Novell Storage Management Services.

metamig, for saving and restoring trustee information when using third-party backup systems for data. For information, see Section A.8, METAMIG (Linux). metamig also supports restoring trustee information for NCP volumes that use the ReiserFS and EXT3 file systems.

In OES SP2 and later, NSS provides an extended attributes (XAttr) extension that supports listing, saving, and restoring the trustee information in the netware.metadata extended attribute. For information, see Section 23.22, Extended Attributes Commands (Linux).

In OES SP2 and later, NSS provides O_NOATIME support for the Linux open API command. For information, see Section 23.23, O_NOATIME Option Support for the Linux open Command (Linux).

Distributed File Services for moving and splitting NSS volumes

Yes

Not supported

Novell Archive and Version Services

Yes

Not supported

Device maintenance support

Activate and deactivate devices by pool.

Activate and deactivate devices by pool.

CD and DVD device recognition

Automatic process with full support for UDF, ISO 9660, and Macintosh HFS formats.

Use CDs and DVDs as read-only NSS volumes.

No; use Linux traditional file system options instead.

CD and DVD image files

Activate as read-only NSS volumes.

No; use Linux traditional file system options instead.

Operating system version detection

Default process

Default process

Cache balancing for NSS cache buffers

Cache is limited to about 85% (by default) of the memory that is not allocated elsewhere. NSS on NetWare uses HighMem and recognizes up to 64 GB of RAM.

You can set several tuning parameters for NSS on NetWare. For information, see Configuring the System Cache to Fine-Tune NSS Performance (NetWare).

For OES SP1 and later, for file data, NSS uses the Linux cache page manger to gain access to all available memory in the system. There are some limits in place so that when copying large files, NSS does not starve other user applications for memory, which is also how it works in NetWare. However, for metadata, NSS is still limited to what is assigned from the kernel below 1 GB cache, typically 60% of the kernel memory limit. (This is the same method used in other Linux file systems such as ReiserFS, Polyserve, XFS, with the exception of EXT.)

For OES, cache for NSS is limited to about 60% of the cache assigned to the Linux kernel memory, which has its own maximum of 1 GB. NSS does not use Linux HighMem. It does not provide autobalancing.

You can specify a minimum cache buffer size. For information, see Configuring the System Cache to Fine-Tune NSS Performance (Linux).

Ability to access DOS partitions on the NetWare server

Load dosfat.nss to treat the partition as a standard NSS volume

No; use Native Linux options instead