Justin, "My concerns are that we will slow down the client backups when we have so many clients running in a small backup window. If we use SATA or FC ATA drive for the primary disk storage pool."
We use ATA in an EMC Clariion as primary disk storage pools. We keep TSM caching turned OFF, simply because the disks are so large that caching doesn't buy us much. We have found that using EMC five-disk RAID-3 arrays for disk pools yields a consistent 40-50 MB/s when pushed by our 2-way 6H1. We use EMC PowerPath to load-balance the data paths to the LUNs. On the other hand, because the ATA hot spare is in the TSM pod, we also created a four-disk RAID-5 array. On that array, we're lucky if we peak at 18 MB/s and sustained performance is usually 12 MB/s or less. All measurements obtained via topas. EMC Clariion code is optimized for (4 x n + 1) disk arrays. I don't know about IBM's. So that's a factor in the performance difference between the two types of arrays. Our two RAID-3 arrays are 1188 GB each, and our one RAID-5 array is 891 GB. We target our file servers to the RAID-3 arrays and have not observed any performance issues. Our Domino and Oracle databases write straight to LTO-1 tape. We point small application servers and CAD workstations at the RAID-5 array, and for those clients, performance is not really an concern. If a backup takes a few minutes longer, so what? We have about 160 clients backing up between 8 pm and 6 am. We have no issues about meeting backup windows since all backups are "hot". Our largest file server has almost two million files, and a typical backup takes about five hours. Most of that is client directory scanning and we are considering using journaling when we go to TSM 5.3 in a couple months. Also, that server is now hosted by VMWare so all I/O has to pass through the VMWare kernel. We have seen a performance drop using VMWare, especially when sending to ATA disks. On last night's backup of that file server, the average network data transfer rate was just under 10 MB/s. We can live with that. I've personally seen the 6H1 swallow 70 MB/s through its NIC so I know the TSM server is not a bottleneck. Just info. Tab Trepagnier TSM Administrator Laitram, L.L.C. "ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> wrote on 07/12/2005 03:54:18 PM: > OK May be I was not clear what we would use the SATA or FC ATA for would > be the primary disk storage pools for nightly backup window > then next morning we would be migrating the backup data to tapes ( FC 3592 > jaguar drives ), current primary storage pools are Enterprise class > (shark disks) and our disk storage pool is currently 1.7 TB for nightly > backup that is what we call cache pool, on one TSM Server and another > TSM server we have 1.6 TB of primary storage pool, then we have a small TSM > server that has 1/2 TB of primary storage pool. In all we backup up 513 > clients nightly with the 3 TSM servers and data that is backed up runs > between 2.7 TB to 3.2 TB. in a backup window of 6 to 8 hours. We do have > about 100 > Oracle RMAN backups included in the backup window running TSM TDPO backups. > If you need more information please let me know. > > My concerns are that we will slow down the client backups when we have so > many clients running in a small backup window. > If we use SATA or FC ATA drive for the primary disk storage pool. > Thanks > > Justin Case > > > > > > > > > > Jin Bae Chi > <[EMAIL PROTECTED] > > To > Sent by: "ADSM: ADSM-L@VM.MARIST.EDU > Dist Stor cc > Manager" > <[EMAIL PROTECTED] Subject > .EDU> Re: How are TSM admins using SATA > for cache pools? > > 07/12/2005 08:24 > AM > > > Please respond to > "ADSM: Dist Stor > Manager" > <[EMAIL PROTECTED] > .EDU> > > > > > > > Justin, > > You may need to tell us more about your configuration and how much data and > how long you need to keep the data before any migration with cache turned > on/off. As you mentioned, you may not need the enterprise class stg for > these particular diskpools unless your SLA requires certain strictness in > performance. Because of the nature of SATA, write I/Os will be troublesome > in any case, so make sure that the controller have enough cache and destage > it later. Some people make mistake buying with single controller config, > but remember that you can't afford to lose it during client backups. Look > for the new SATA II which comes with a lot of fixes and also, > > TSM takes pretty much any disks that OS sees as available so consider > giving multiple diskpools. Depending on what tape storage you have, but > writing direct to tape device today is not a bad idea in many cases, so > consider not only diskpool for immediate writes, but also tape devices such > as FC LTO2 or LTO3. For the better pricing, ATA drives with proper RAID > config could be considered. > > When configured correctly, SATA drives will be performing as good as other > types of disks. I've been running and happy with them for a while for TSM > and other applications. Hope this helps. > > > Gus > > > >>> [EMAIL PROTECTED] 07/11/05 10:01 PM >>> > > How are TSM admins using SATA disks for cache pools ? > > What type of SATA disks are being used and at what raid levels ? > > How satisfied are you with the backup times with SATA disks for cache pools > on TSM ? > > We are looking at SATA for TSM cache pools is why the questions because > we are using enterprise class storage for cache pools on TSM currently at a > high cost. > > Looking for cheaper disks for TSM cache pools. > Thanks > > Justin Case > TSM Administrator/Storage Administrator > IT Analyst OIT Infrastructure Support > 334 Blackwell Street > 2nd floor Suite 2108 Durham,NC 27701 > Duke University > Email: [EMAIL PROTECTED]
