Instruction/ maintenance manual of the product 3.5.2 Quantum
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6-01376-14 StorNext 3.5.2 ® StorNext File System T uning Guide File System T uning Guide File System T uning Guide.
StorNext 3.5.2 File Syst em Tuning Guide, 6-01376-14 , Ver. A, Rel. 3.5.2 , February 2010, Made in USA. Quantum Corporation provides this publ ication “as is” without warranty of an y kind, either express or implied, including but not limited to the implied warranties of merc hantability or fitness for a particular purpose.
StorNext File System Tuning Gu ide i Content s Chapter 0 StorNext File System Tuning 1 The Underlying Storage System ............. ... ......... .............. .............. .............. ... 1 RAID Cache Configuration .............. .............. .
StorNext File System Tuning Guide 1 0 S torNext File System T uning The StorNext File System (SNFS) pr ovides extremely high performance for widely varying scenarios. Many factors determine the level of performance you will realiz e. In particular, the performance characteristics of the underlying st orage system are the most critical factors.
StorNext File System T uning The Underlying Storage System StorNext File System Tuning Guide 2 RAID Cache Configuration 0 The single most i mportant RAID tuning component is the cache configuration. This is particular ly t rue for small I/O operat ions.
StorNext File System T uning 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 critical perf ormance factor. Write-back caching can be an effective approach to mini mizing I/O latency and optimizing metadata operations throughput.
StorNext File System T uning The Underlying Storage System StorNext File System Tuning Guide 4 While read-ahead caching improves sequ ential read performance, it does not help highly transactional perf ormance. Furthermore, some SNFS customers actually observe maximum large sequential read throughput by disabling caching .
StorNext File System T uning File Size Mix and Application I/O Characteristics StorNext File System Tuning Guide 5 example, varying the stripe size an d running lmdd with a range of I/O sizes might be useful to determine an optimal stripe size multiple to configure the SNFS StripeBreadth .
StorNext File System T uning File Size Mix and Application I/O Characteristics StorNext File System Tuning Guide 6 Buffer Cache 0 Reads and writes that aren't well-for med utilize the SNFS buffer cache. This also includes NFS or CIFS -bas ed traffic because the NFS and CIFS daemons defeat well-formed I/Os issued by the application.
StorNext File System T uning SNFS and Virus Checking StorNext File System Tuning Guide 7 It can be useful to use a tool such as netperf to help verify network performance characteristics. SNFS and V irus Checking Virus-ch ecking so ftware can se vere ly degrade the performance of any file system, including SNFS .
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 8 It can be useful to use a tool like netperf to help verify the Metadata Network performance characte ristics. For example, if netperf -t TCP_RR reports less than 15,000 transactions per second capacity, a performance penalty may be incurred.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 9 However, it is critical that the MDC system have e nough physical memory available to ensure that the FSM process do esn’t get swap ped out. Otherwise, severe performance degradation and syst em instability can result.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 10 MultiPathMethod Rotate Node CvfsDisk6 0 Node CvfsDisk7 1 [S tripeGroup MetaFiles] S tatus UP Meta D ata.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 11 For optimal performance, files that are accessed using large D MA-based I/O could be steered to wide-strip e stripe groups. Less performance- critical file s could be steered to slow disk stripe groups.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 12 Example: [stripeGroup VideoFiles] S tatus UP Exclusive Y es ##These T wo lines set Exclusive stripeGrou.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 13 ThreadPoolSize 0 This setting consumes u p to 512 KB memory times the number specified. Increasing this value can improve c oncurrency of metadata operations.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 14 For metadata disk size, you must have a minimum of 25 G B, with more space allocated depending on the numb er of files per directory and the size of your fi le system.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 15 JournalSize 0 The optimal settings for JournalSize are in the range between 16M and 64M, depending on the FsBlockSize . Avoid val ues greater than 64M due to potentially severe impacts on startu p and failover times.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 16 The following items are a few things to watch out for: • A non-zero value for FSM wait SUMMAR Y journal waits indicates insufficient IOPS performance of th e disks assigned to the metadata stripe group.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 17 preallocation and stripe alignment. In the directory-to-directory copy mode (for example, cvcp source_dir destination _dir ,) cvcp conditionally uses the Bulk Create API to provide a dramatic small file copy performance boost.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 18 Sample use cases: • Verify that I/O properties are as expe cted. You can use the VFS trace to ensure th at the displayed properties are consistent with expectations, such as being well formed; buffered versus DMA; shared/non-shared; or I/O size.
StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 19 displayed by the cvadmin who command). If all is specified, the test is run against each client in turn. The test is run for 2 seconds, unle ss a value for seconds is specified.
StorNext File System T uning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Guide 20 background for improved performance. The default setting is optimal in most scenarios.
StorNext File System T uning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Guide 21 anticipated traffic between all Di stributed LAN clients and servers connected to them. A network switch that is dropping pack ets will cause TCP retransmissions.
StorNext File System T uning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Guide 22 It can be useful to use a tool like netperf to help verify the performance characteristics of each Distri buted LAN network.
StorNext File System T uning Distributed LAN Servers StorNext File System Tuning Guide 23 In the diagram there are two subnetwork s: the blue subnetwork (10.0.0.x) and the red subnetwork (192.168.9.x). Se rvers such as S1 are connecte d to both the blue and red subnetwork s, and can each provide up to 2 GByte/s of throughput to clients.
StorNext File System T uning Distributed LAN Client Vs. Legacy Network Attached Storage StorNext File System Tuning Guide 24 Distributed LAN Client Vs. Legacy Network Attached S torage 0 StorNext provides support for lega cy Network Attached Storage (NAS) protocols, including Network File Sys tem (NFS) and Common Interne t File System (CIFS).
StorNext File System T uning Distributed LAN Client Vs. Legacy Network Attached Storage StorNext File System Tuning Guide 25 Load Balancing 0 DLC automatically ma kes use of all available Dist ributed LAN Servers in an active/active fashion, and evenly spreads I/O across them.
StorNext File System T uning Windows Memory Requirements StorNext File System Tuning Guide 26 Windows Memory Requirements Beginning in version 2.6.1, StorNext includes a number of performance enhancements that enable it to bette r react to changing customer load.
StorNext File System T uning Windows Memory Requirements StorNext File System Tuning Guide 27 The more cvnodes that there are encached on the client, the fewer trips the client has to make over the wire to contact the FSM. Each cvnode is approximately 1462 bytes in size and is allocated from the non-paged pool.
StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 28 Sample FSM Configuration File This sample configuration file is locat ed in the SNFS install directory under the examples subdirectory named example.
StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 29 # # ThreadP oolSize 64 # defaul t 16, 2 MB m emory per thre ad # InodeCacheSize 32K # 800-1000 bytes eac.
StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 30 ****************** ************** ******************* ****************** **** [Disk CvfsDisk0] S tatus U.
StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 31 [Disk CvfsDisk8] S tatus UP T ype VideoDrive [Disk CvfsDisk9] S tatus UP T ype VideoDrive [Disk CvfsDisk.
StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 32 S tatus UP T ype Da taDrive [Disk CvfsDisk17] S tatus UP T ype Da taDrive # ****************** *************** *** *************** **** ****************** # A stripe section for defining stripe groups.
StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 33 S tatus UP Exclusive Y es##Exclusive StripeGroup for V ideo Files Only## Affinity VidFiles Read Enabled .
StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 34 Wr it e Enabled S trip eBreadth 256K MultiPathMethod Rotate Node CvfsDisk14 0 Node CvfsDisk15 1 Node Cvf.
An important point after buying a device Quantum 3.5.2 (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 3.5.2 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 3.5.2 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Quantum 3.5.2 you will learn all the available features of the product, as well as information on its operation. The information that you get Quantum 3.5.2 will certainly help you make a decision on the purchase.
If you already are a holder of Quantum 3.5.2, 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 3.5.2.
However, one of the most important roles played by the user manual is to help in solving problems with Quantum 3.5.2. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Quantum 3.5.2 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
