Instruction/ maintenance manual of the product 3.1.4.1 Quantum
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6-01376-15 Rev A StorNext ® 3.1.4.1 StorNext File System T uning Guide File System T uning Guide.
ii Quantum Product Name User’s Guide Document Title, 6-0137 6-15 Rev A, May 2010, Product of USA. Quantum Corporation provides this publication “as is” without warranty of any kin d, either express or implied, including but not limited to the i mplied warranties of merchantability or fitness for a particular purpose.
StorNext File System Tuning Guide iii Contents The Underlying Storage System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 File Size Mix and Applicatio n I/O Characteristics . . . . . . . . . . . . . . . . . . 5 SNFS and Virus Checking .
Contents iv StorNext File System Tuning Guide.
StorNext File System Tuning Guide 1 StorNext File System T uning The StorNext File Syste m (SNFS) provides ex tremely high per formance for widely varying scenarios. Many factors determine the level of performance you will realize. In particular , the performance characteristics of the underlying stor age system are the most critical factors.
StorNext File System Tuning The Underlying Storage System 2 StorNext File System Tuning Guide RAID Cache Configuration The single most important RAID tuning component is the cache configuration.
StorNext File System Tuning The Underlying Storage System StorNext File System Tuning Guide 3 operations involve a very high rate of small writes to the metadata disk, so disk latency is the critic al perf ormance factor . Write-bac k caching can be an effective approach to mini mizing I/O latency and optimi zing metadata operations throughput.
StorNext File System Tuning The Underlying Storage System 4 StorNext File System Tuning Guide While read-ahead caching improves sequential read performance, i t does not help highly tra nsactional performance. F urthermore, some SNFS customers actually observe maximu m large seque ntial read throughput by disabling caching.
StorNext File System Tuning File Size Mix and Application I/O Characteristics StorNext File System Tuning Guide 5 It can be useful to use a tool such as lmdd to help determine the storage system performance characteristic s and choose optimal settings.
StorNext File System Tuning File Size Mix and Applic ation I/O Characteristics 6 StorNext File System Tuning Guide and auto_dma_write_length , described i n the Mount Command Options on page 19 . Buffer Cache Reads and writes that aren't well-formed util ize the SNFS buffer cache.
StorNext File System Tuning SNFS and Virus Checking StorNext File System Tuning Guide 7 If performance requirements canno t be achieved with NFS or CIFS, consider using a StorNext Distributed LAN client or fibre-chan nel attached client. It can be useful to use a tool such as netperf to help verify network performance characteristics.
StorNext File System Tuning The Metadata Controller System 8 StorNext File System Tuning Guide ethtool too l can be very useful to investigate and adjus t speed/dupl ex settings. It can be useful to use a tool like netpe rf to help verify the Metadata Network performance characteristics.
StorNext File System Tuning The Metadata Controller System StorNext File System Tuning Guide 9 used to realize performance gains from increased memory: BufferCacheSize , InodeCacheSize , and ThreadPoolSize . However , it is critical that the MDC system have enough physical memory available to ensure that the FSM process doesn’t get swapped out.
StorNext File System Tuning The Metadata Controller System 10 StorNext File System Tuning Guide StripeBreadth 256K MultiPathMethod Rotate Node CvfsDisk6 0 Node CvfsDisk7 1 [StripeGroup MetaFiles] Stat.
StorNext File System Tuning The Metadata Controller System StorNext File System Tuning Guide 11 Affinity AudFiles ##for Audio Fil es Only## Read Enabled Write Enabled StripeBreadth 1M MultiPathMethod Rotate Node CvfsDisk4 0 Node CvfsDisk5 1 Note: Affinity names cannot be lon ger than eight characters.
StorNext File System Tuning The Metadata Controller System 12 StorNext File System Tuning Guide BufferCacheSize This setting consumes up to 2X bytes of memory times the number specified.
StorNext File System Tuning The Metadata Controller System StorNext File System Tuning Guide 13 Example: ThreadPoolSize 32 # default 16, 512 KB memory per thread ForcestripeAlignment This setting should always be set to Y es. This is critical if the largest Str i pe Br e adt h defined is greater than 1MB.
StorNext File System Tuning The Metadata Controller System 14 StorNext File System Tuning Guide This setting is not adj ustable after initial file system creation, so i t is very important to give it careful consi deration during initi al configuration.
StorNext File System Tuning The Metadata Controller System StorNext File System Tuning Guide 15 This setting is adjustabl e using the cvup datefs utility . For more information, see the cvup datefs man page. Example: JournalSize 16M SNFS T ools The snfsdefrag tool is very useful to iden tify and correct file extent fragmentation.
StorNext File System Tuning The Metadata Controller System 16 StorNext File System Tuning Guide •L a r g e v a l u e f o r FSM threads SUMMAR Y max busy indicates the FSM configuration setting Threa dPoolSize is insufficient.
StorNext File System Tuning The Metadata Controller System StorNext File System Tuning Guide 17 The cvdbset utility has a special “Perf” trace flag that is very useful to analyze I/O performance.
StorNext File System Tuning The Metadata Controller System 18 StorNext File System Tuning Guide • Identify disk performance issues. If Device throughput is inconsistent or less than expected, it might indicate a slow disk in a stripe group, or that RAID tuning is necessary .
StorNext File System Tuning The Metadata Controller System StorNext File System Tuning Guide 19 slower CPU.) Differences in latency over time for the same system can indicate new hardware problems, such a s a network interface goin g bad.
StorNext File System Tuning The Distributed LAN (Disk Proxy) Networks 20 StorNext File System Tuning Guide The dircachesize option sets the size of th e directory information cache on the client. This cache can dramatically improve the speed of readdir operations by reducing metadata network message traffic between the SNFS client and FSM.
StorNext File System Tuning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Guide 21 It is best practice to have all SN FS Distributed LAN clients and servers directly attached to the same ne twork switch. A router be tween a Distributed LAN client and server co uld be easily overwhelmed by the data rates required.
StorNext File System Tuning The Distributed LAN (Disk Proxy) Networks 22 StorNext File System Tuning Guide Network Configuration and T opology Fo r maximum throughput, SNFS distributed LAN can utilize mult iple NICs on both clients and servers.
StorNext File System Tuning Distributed LAN Servers StorNext File System Tuning Guide 23 maximum of 1 GByte/s of throughput. SNFS automatically load- balances among NICs and se rvers to maximize throughput for all clients. Note: The diagram shows separate physic al switches used for the two subnetworks.
StorNext File System Tuning Distributed LAN Client Vs. Legacy Netwo rk Attached Storage 24 StorNext File System Tuning Guide •P e r f o r m a n c e •F a u l t T o l e r a n c e •L o a d B a l a .
StorNext File System Tuning Windows Memory Requirements StorNext File System Tuning Guide 25 Robustness and Stability The code pat h for DLC is simp ler , invo lves fewer file system stacks, and is not integrated with ke rnel components th at constantly change with every operating system release ( for example, the Linux NFS code).
StorNext File System Tuning Windows Memory Requirements 26 StorNext File System Tuning Guide being sent to the application log and cvlog.txt about socket failures with the status code (10555) which is ENOBUFS. The solution is to adjust a few parameters on the Cache Parameters tab in the SNFS control panel ( cvntclnt ).
StorNext File System Tuning Sample FSM Configuration F ile StorNext File System Tuning Guide 27 Sample FSM Configuration File This sample configuration f ile is lo cated in the SNFS in stall directo ry under the exampl es subdirectory name d example.cfg.
StorNext File System Tuning Sample FSM Configuration File 28 StorNext File System Tuning Guide # StripeAlignSize 2M # auto alignment, default MAX(StripeBreadth) # OpHangLimitSecs 300 # default 180 sec.
StorNext File System Tuning Sample FSM Configuration F ile StorNext File System Tuning Guide 29 [Disk CvfsDisk3] Status UP Type VideoDrive [Disk CvfsDisk4] Status UP Type VideoDrive [Disk CvfsDisk5] S.
StorNext File System Tuning Sample FSM Configuration File 30 StorNext File System Tuning Guide [Disk CvfsDisk15] Status UP Type DataDrive [Disk CvfsDisk16] Status UP Type DataDrive [Disk CvfsDisk17] Status UP Type DataDrive # ************************************ ************************ # A stripe section for defining stri pe groups.
StorNext File System Tuning Sample FSM Configuration F ile StorNext File System Tuning Guide 31 Node CvfsDisk3 1 Node CvfsDisk4 2 Node CvfsDisk5 3 Node CvfsDisk6 4 Node CvfsDisk7 5 Node CvfsDisk8 6 No.
StorNext File System Tuning Sample FSM Configuration File 32 StorNext File System Tuning Guide.
An important point after buying a device Quantum 3.1.4.1 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Quantum 3.1.4.1 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Quantum 3.1.4.1 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Quantum 3.1.4.1 you will learn all the available features of the product, as well as information on its operation. The information that you get Quantum 3.1.4.1 will certainly help you make a decision on the purchase.
If you already are a holder of Quantum 3.1.4.1, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Quantum 3.1.4.1.
However, one of the most important roles played by the user manual is to help in solving problems with Quantum 3.1.4.1. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Quantum 3.1.4.1 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
