Quantum 6-01376-05 manuale d’uso

6-01376-05 StorNext 3.0 ® StorNext File System T uning Guide File System T uning Guide File System T uning Guide[...]

Document Title, 6-01376- 05 , Ver. A, Rel. 3.0 , March 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 revise this publicatio n f[...]

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

StorNext File System Tuning Gu ide 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. How[...]

StorNext File System T uning The Underlying Storage System StorNext File System Tuning Gu ide 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 exc[...]

StorNext File System T uning The Underlying Storage System StorNext File System Tuning Gu ide 3 metadata operations throughput. This is easily observed in the hourly 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 sysm[...]

StorNext File System T uning The Underlying Storage System StorNext File System Tuning Gu ide 4 it severely degrades typica l scenarios. 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 be changed af[...]

StorNext File System T uning File Size Mix and Application I/O Characteristics StorNext File System Tuning Gu ide 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, proporti[...]

StorNext File System T uning File Size Mix and Application I/O Characteristics StorNext File System Tuning Gu ide 6 Command Options on page 16). So, it is typically most important to optimize the RAID cache configurati on settings described earlier in thi s document. It is usually best to configure the RA ID stripe size no greater than 256K for opt[...]

StorNext File System T uning The Metadata Network StorNext File System Tuning Gu ide 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 100[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Gu ide 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 ca[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Gu ide 9 Example: [stripeGroup RegularFiles] S tatus UP Exclusive No ##Non-Exclusive stripeGroup for all Files## 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 Gu ide 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 Gu ide 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 metadata 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 Gu ide 12 severely consumes metadata space in cases where the file-to-directory ratio is less than 100 to 1. However, startup and fail over time can be minimized by incre asing FsBlockSize. This is very important for mult i- terabyte file systems, and especial l[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Gu ide 13 It also possible to trigger an instan t FSM st atistics report by setting t he Once Only debug flag using cvadmin . For example: cvadmin -F snfs1 -e ‘debug 0x01000000’ ; tail -100 /usr/cvfs/data/snfs1/log/cvlog The following items are a few things [...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Gu ide 14 The cvcp utility is a higher performance alternative to commands such as cp and ta r . The cvcp utilit y achieves high perf ormance by using threads, large I/O buffers, preallocation, stripe alignment, DMA I/O tr ansfer, and Bulk Create. Also, the cvcp[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Gu ide 15 • Zr: Hole in file was zeroed Both traces also report file offset, I/O size, latency (mics), and inode number. 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 c[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Gu ide 16 The latency -test command has the following syntax: latency-test index-number [ seconds ] latency-test all [ seconds ] If an index-number is specified, the test is r un between the currently- selected FSM and the specifie d client. (Clie nt index numbe[...]

StorNext File System T uning The Metadata Controller System StorNext File System Tuning Gu ide 17 The buffer cache I/O size is adjusted using the cachebufsize setti ng. The default setting is usually optimal; however, sometimes performance can be improved by increasing this setti ng to match the RAID5 stripe size. Unfortunately, this is often not p[...]

StorNext File System T uning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Gu ide 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 Gu ide 19 Wi t h i n e a c h Di s t r ib u t ed L A N n et w o rk , i t is b e st p r a c ti c e to h a v e a l l S NF S Distributed LAN clients and servers directly attached to the same network switch. A router betwe en a Distributed LAN client and s[...]

StorNext File System T uning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Gu ide 20 Network Configur at ion and T opology 0 A common source of difficult-to-diag nose issues with SNFS is improper IP network configuration. Many incorrect IP conf igurations might appear to work when tested with particular applications or parti[...]

StorNext File System T uning The Distributed LAN (Disk Proxy) Networks StorNext File System Tuning Gu ide 21 Figure 1 Multi-NIC Hardware and IP Configurati on Diagram SAN Distributed LAN Server A 10.0.0.27 172.16.47.27 192.168.1.27 192.168.2.27 Distributed LAN Server B 10.0.0.28 172.16.47.28 192.168.1.28 192.168.2.8 SNFS SAN Client 10.0.0.12 172.16[...]

StorNext File System T uning Distributed LAN Servers StorNext File System Tuning Gu ide 22 Distributed LAN Servers Distributed LAN Servers must ha ve sufficient memory. When a Distributed LAN Server does not have sufficient memory, its performance in servicing Distributed LAN I/O requests might suffer. In some cases (particul arly on Windows,) it m[...]

StorNext File System T uning Windows Memory Requirements StorNext File System Tuning Gu ide 23 mysteriously dying, repeated FSM reconnect attempts, and messages 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 i[...]

StorNext File System T uning Windows Memory Requirements StorNext File System Tuning Gu ide 24 water mark is reached, for example 128. The Max water m ark is for situations where memory is very tight. The normal purge algorithms takes access time into account when determining a candidate to evict from the cache; in tight memory situations (when the[...]

StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Gu ide 25 Sample FSM Configuration File This sample configuration file is locat ed in the SNFS install directory under the ex amples subdir ectory named example.cfg. # **************************************************************************** # A global section[...]

StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Gu ide 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 Gu ide 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 VideoD[...]

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

StorNext File System T uning Sample FSM Configuration File StorNext File System Tuning Gu ide 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[...]