Quantum 6-01376-07 manual

6-01376-07 StorNext 3.1 ® StorNext File System T uning Guide File System T uning Guide File System T uning Guide[...]

StorNext 3.1 File System Tuning Guide, 6-01376-07 , Ver. A, Rel. 3.1 , October 2007, 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. Quantum Corporation may re[...]

StorNext File System Tuning Gu ide i Content s Chapter 1 StorNext File System Tuning 1 The Underlying Storage System ............. ... ......... .............. .............. .............. ... 1 RAID Cache Configuration .............. .............. .............. ............... .............. 2 RAID Write-Back Caching .... .............. .......[...]

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. Howe[...]

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. Contemporary RAID systems such as the EMC CX series and the various Engenio systems provide exce[...]

StorNext File System T uning The Underlying Storage System StorNext File System Tuning Guide 3 File System Mana ger (FSM) stati stics reports in the cvlog file. For example, here is a message line from the cvlog file: PIO HiPriWr SUMMAR Y SnmsMetaDisk0 sysavg/350 sysmin/333 sysmax/367 This statistics message rep orts av erage, minimum, and maximum [...]

StorNext File System T uning The Underlying Storage System StorNext File System Tuning Guide 4 unusual cases, it severely degrades typical sce narios. Therefore, it is unsuitable for most environments. RAID Level, Segment Size, and S tripe Size 0 Configuration settings such as RAID level, segment si ze, and stripe size are very important and cannot[...]

StorNext File System T uning File Size Mix and Application I/O Characteristics StorNext File System Tuning Guide 5 File Size Mix and Application I/O Characteristics It is always valuabl e to understand th e file size mix of the target dataset as well as the application I/O characte ristics. This includes t he number of concurrent streams, proportio[...]

StorNext File System T uning File Size Mix and Application I/O Characteristics StorNext File System Tuning Guide 6 It is usually best to configure the RA ID stripe size no greater than 256K for optimal small file buffer cache performance. For more buffer cache configuration settings, see Mount Command Options on page 17. NFS / CIFS 0 It i s b es t [...]

StorNext File System T uning The Metadata Network StorNext File System Tuning Guide 7 The Metadat a Network As with any client/server protocol, SNFS perfor mance is subject to the limitations of the underlying network. Therefore, it is recommended that you use a dedicated Metadata Networ k to avoid contention with other network traffic. Either 100B[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 8 Some metadata operations such as fi le creation can be CPU intensive, and benefit from increased CPU power. The MDC platform is important in these scenarios because lower clock- speed CPUs such as Sparc and M ips degrade performance. Other operations can[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 9 Example: [stripeGroup RegularFiles] S tatus UP Exclusive No ##Non-Exclusive stripeGroup for all Fi les## Read Enabled Wr it e Enabled S trip eBreadth 256K MultiPathMethod Rotate Node CvfsDisk6 0 Node CvfsDisk7 1 Affinities 0 Affinities are another stripe[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 10 Str i p eB re a dth 0 T h i s s e t t i n g m u s t m a t c h t h e R A I D s t r i p e s i z e o r b e a m u l t i p l e o f t h e R A I D stripe size. Matching th e RAID stripe size i s usually the most optimal setting. However, depending on the RAID [...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 11 InodeCacheSize 0 This setting consumes about 800-1000 bytes of memory times the nu mber specified. Increasing t his value can reduce latency of any metadat a operation by performing a hot cache access to inode information instead of an I/O to get inode [...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 12 Settings greater than 64K are not recommended because performance will be adversel y impacted due to in efficient metad ata I/O operations. Values less than 16K are not reco mmended in most scenarios because startup and failover time may be ad versely i[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 13 man cvfs_config page.) T he snfsdefrag man page explains the command options in greater detail. FSM hourly statistics reporting is another very useful tool. This can show you the mix of metadata operations be ing invoked by cl ient processes, as well as[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 14 SNFS supports the Windows Perfmon utility. This provides many useful statistics counters for the SNFS client component. To instal l, obtain a copy of cvfsperf .dll from the SCM team in Denver and copy it into the c:/ winnt/system32 directory on the SN F[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 15 The “PERF: VFS” trace shows throughput measured for the read or write system call and significant aspects of the I/O, incl uding: •D m a : D M A •B u f : B u f f e r e d • Eof: File extended • Algn: Well-formed DMA I/O • Shr: File is share[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 16 • Identify read/modify/w rite condition. If buffered VFS writes are causing De vice reads, it might be beneficial to match I/O request size to a multiple of t he “cachebufsize” (default 64KB; see mount_cvfs man page). Another way to avoid this is [...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Guide 17 Mount Command Options 0 The following SNFS mount command settings are explained in greater detail in the mount_cvfs man page. The default size of the buffer cache varies by platform and main memory size, and ranges between 32MB and 256M B. And, by defau[...]

StorNext File System T uning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Guide 18 SNFS External API 0 The SNFS External API might be useful in some scenarios because it offers programmatic use of special SN FS performance capabilities such as affinities, preallocation, and quality of service. For more information, see the [...]

StorNext File System T uning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Guide 19 is set to auto-detect but the host is set to 1000Mb/full , you will observe a high error rate and extremely poor perfor mance. On Linux the ethto ol command can be very useful to invest igate and a djust speed/duplex settings. In some cases, [...]

StorNext File System T uning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Guide 20 Figure 1 Multi-NIC Hardware and IP Configurati on Diagram 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[...]

StorNext File System T uning Distributed LAN Servers StorNext File System Tuning Guide 21 Distributed LAN Servers Distributed LAN Servers must ha ve suff icient memory. When a Distributed LAN Server does not have sufficient me mory, its performance in servicing Distributed LAN I/O requests might suffer. In some cases (particul arly on Windows,) it [...]

StorNext File System T uning Distributed LAN Client Vs. Legacy Network Attached Storage StorNext File System Tuning Guide 22 Performance 0 DLC outperforms NFS and CIFS for single-stream I/O and provides higher aggregate bandwidth. For in ferior NFS client implementations, the difference can be more th an a factor of two. DLC also makes extremely ef[...]

StorNext File System T uning Windows Memory Requirements StorNext File System Tuning Guide 23 Therefore, DLC provides incr eased st abilit y that is comparable to the StorNext SAN Client. Consistent Security Model 0 DLC clients hav e the same security mo del as StorNext SAN clients. When CIFS and NFS are used, some security models aren’t supporte[...]

StorNext File System T uning Windows Memory Requirements StorNext File System Tuning Guide 24 The first is the Directory Cach e Size . The default is 10 (MB). If you do not have large directories, or do not pe rform lots of directory scans, this number can be reduced to 1 or 2 MB. The impact wil l be slightly slower directory lookups in directories[...]

StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 25 Sample FSM Configuration File This sample configuration file is locat ed in the SNFS install directory under the examples subdirectory named example.cfg. # **************************************************************************** # A global section fo[...]

StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 26 MAX(StripeBreadth) # MaxMBPerClientReserve 50 # in MBs, default 100 MB reserved per client # OpHangLimitSecs 300 # default 180 secs # DataMigrationThreadPoolSize 128 # Managed only, default 8 # ************************************************************[...]

StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 27 [Disk CvfsDisk4] Status UP Type VideoDrive [Disk CvfsDisk5] Status UP Type VideoDrive [Disk CvfsDisk6] Status UP Type VideoDrive [Disk CvfsDisk7] Status UP Type VideoDrive [Disk CvfsDisk8] Status UP Type VideoDrive [Disk CvfsDisk9] Status UP Type VideoDr[...]

StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 28 [Disk CvfsDisk17] Status UP Type DataDrive # **************************************************************************** # A stripe section for defining stripe groups. # **************************************************************************** [Strip[...]

StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Guide 29 [StripeGroup AudioFiles] Status UP Exclusive Yes ##Exclusive StripeGroup for Audio File Only## Affinity AudioFiles Read Enabled Write Enabled StripeBreadth 1M MultiPathMethod Rotate Node CvfsDisk10 0 Node CvfsDisk11 1 Node CvfsDisk12 2 Node CvfsDisk13 3 [...]