I have a strange performance issue that I am trying to work out involving network attached storage being used for TSM stgpool volumes.
The TSM server is AIX 5.3, and the network is a dedicated Gbit. We started out using iSCSI for the storage pool volumes creating 10 X 250GB volumes and placing a single logical volume per 250GB physical volume, and letting TSM do the load balancing. We are a small shop, and the 30-40 MB/s performance that we were seeing in backups was acceptable. That is until we had to audit some volumes. For the audit, we are seeing abysmal performance. Approximately 3-5 MB/s per volume. Adding volumes increases the total throughput, but the performance per volume remains around 3-5 MB/s. From the command line we can get 30-60 MB/s using dd to and from an iSCSI volume. So we did some testing on NFS. Using NFS, we are able to get 60-80 MB/s from the AIX OS using dd both read and write. So we decided to create volumes on the NFS mount. The "define vol" command ran for 10+ hours on a 100 GB volume at 2 MB/s. Thinking it was just the def vol that was a problem, I ran a move data to the new volume, and it ran at 3-5 MB/s. I then ran an audit on the volume, and again I am only getting 3-5 MB/s. This seems like a tuning issue inside TSM, but I could not tell you what parameter would cause such a slow down. I have done my homework on this, and have not found any relevant posts. If anyone has some suggestions, I would love to hear them. As a side note, defining a volume on the local root drive runs at 16-20 MB/s. tsm: TSM>q option Server Option Option Setting Server Option Option Setting ----------------- -------------------- ----------------- -------------------- CommTimeOut 60 IdleTimeOut 15 BufPoolSize 32768 LogPoolSize 512 MessageFormat 1 Language AMENG Alias Halt HALT MaxSessions 25 ExpInterval 24 ExpQuiet No EventServer Yes ReportRetrieve No DISPLAYLFINFO No MirrorRead DB Normal MirrorRead LOG Normal MirrorWrite DB Sequential MirrorWrite LOG Parallel TxnGroupMax 256 MoveBatchSize 1000 MoveSizeThresh 2048 RestoreInterval 1,440 DisableScheds No NOBUFPREfetch No AuditStorage Yes REQSYSauthoutfile Yes SELFTUNEBUFpools- No ize DBPAGEShadow No DBPAGESHADOWFile dbpgshdw.bdt MsgStackTrace On QueryAuth None LogWarnFullPerCe- 90 ThroughPutDataTh- 0 nt reshold ThroughPutTimeTh- 0 NOPREEMPT ( No ) reshold Resource Timeout 60 TEC UTF8 Events No AdminOnClientPort Yes NORETRIEVEDATE No IMPORTMERGEUsed Yes DNSLOOKUP Yes NDMPControlPort 10,000 NDMPPortRange 0,0 SHREDding Automatic SanRefreshTime 0 TCPPort 1500 TcpAdminport 1500 HTTPPort 1580 TCPWindowsize 64512 TCPBufsize 32768 TCPNoDelay Yes CommMethod TCPIP MsgInterval 1 ShmPort 1510 FileExit UserExit FileTextExit AssistVCRRecovery Yes AcsAccessId AcsTimeoutX 1 AcsLockDrive No AcsQuickInit Yes SNMPSubagentPort 1521 SNMPSubagentHost 127.0.0.1 SNMPHeartBeatInt 5 TECHost TECPort 0 UNIQUETECevents No UNIQUETDPTECeven- No ts Async I/O No SHAREDLIBIDLE No 3494Shared No CheckTrailerOnFr- On ee SANdiscovery On SSLTCPPort SSLTCPADMINPort SANDISCOVERYTIME- 15 Server Name: Server host name or IP address: Server TCP/IP port number: 1500 Crossdefine: On Server Password Set: Yes Server Installation Date/Time: 11/11/08 15:01:10 Server Restart Date/Time: 12/28/09 11:50:39 Authentication: On Password Expiration Period: 9,999 Day(s) Invalid Sign-on Attempt Limit: 0 Minimum Password Length: 0 Registration: Closed Subfile Backup: No Availability: Enabled Accounting: Off Activity Log Retention: 5 Day(s) Activity Log Number of Records: 9243 Activity Log Size: 1 M Activity Summary Retention Period: 30 Day(s) License Audit Period: 1 Day(s) Last License Audit: 12/28/09 23:50:44 Server License Compliance: Valid Central Scheduler: Active Maximum Sessions: 25 Maximum Scheduled Sessions: 12 Event Record Retention Period: 30 Day(s) Client Action Duration: 5 Day(s) Schedule Randomization Percentage: 25 Query Schedule Period: Client Maximum Command Retries: Client Retry Period: Client Scheduling Modes: Any Log Mode: Normal Database Backup Trigger: Disabled BufPoolSize: 32,768 K Active Receivers: CONSOLE ACTLOG Configuration manager?: Off Refresh interval: 60 Last refresh date/time: Context Messaging: Off Table of Contents (TOC) Load Retention: 120 Minute(s) Machine Globally Unique ID: 00.00.00.00.b0.33.11.dd.b0.f9.08.63.01.02.03.02 Archive Retention Protection: Off Encryption Strength: AES