btape getting 89 MBs, so maybe my disk and sql updating is effecting the speed? note drive has a 16384 blocksize, ran tapeinfo on the drive...gary
[root@genepi1 bacula]# btape -c /etc/bacula/bacula-sd.conf /dev/nst0 Tape block granularity is 1024 bytes. btape: butil.c:284 Using device: "/dev/nst0" for writing. 01-Dec 12:29 btape JobId 0: 3301 Issuing autochanger "loaded? drive 0" command. 01-Dec 12:29 btape JobId 0: 3302 Autochanger "loaded? drive 0", result is Slot 12. btape: btape.c:476 open device "LTO-4" (/dev/nst0): OK *speed file_size=3 skip_raw btape: btape.c:1082 Test with zero data and bacula block structure. btape: btape.c:960 Begin writing 3 files of 3.221 GB with blocks of 2097152 bytes. +++4 btape: btape.c:608 Wrote 1 EOF to "LTO-4" (/dev/nst0) btape: btape.c:410 Volume bytes=3.221 GB. Write rate = 89.47 MB/s +++ btape: btape.c:608 Wrote 1 EOF to "LTO-4" (/dev/nst0) btape: btape.c:410 Volume bytes=3.221 GB. Write rate = 89.47 MB/s +++ btape: btape.c:608 Wrote 1 EOF to "LTO-4" (/dev/nst0) btape: btape.c:410 Volume bytes=3.221 GB. Write rate = 89.47 MB/s btape: btape.c:384 Total Volume bytes=9.663 GB. Total Write rate = 89.47 MB/s btape: btape.c:1094 Test with random data, should give the minimum throughput. btape: btape.c:960 Begin writing 3 files of 3.221 GB with blocks of 2097152 bytes. +++ btape: btape.c:608 Wrote 1 EOF to "LTO-4" (/dev/nst0) btape: btape.c:410 Volume bytes=3.221 GB. Write rate = 16.02 MB/s +++ btape: btape.c:608 Wrote 1 EOF to "LTO-4" (/dev/nst0) btape: btape.c:410 Volume bytes=3.221 GB. Write rate = 33.90 MB/s +++ btape: btape.c:608 Wrote 1 EOF to "LTO-4" (/dev/nst0) btape: btape.c:410 Volume bytes=3.221 GB. Write rate = 44.12 MB/s btape: btape.c:384 Total Volume bytes=9.663 GB. Total Write rate = 26.18 MB/s [root@genepi1 bacula]# tapeinfo Usage: tapeinfo -f <generic-device> [root@genepi1 bacula]# tapeinfo -f /dev/changer Product Type: Medium Changer Vendor ID: 'OVERLAND' Product ID: 'NEO Series ' Revision: '0504' Attached Changer API: No SerialNumber: '2B81000045' SCSI ID: 1 SCSI LUN: 1 Ready: yes [root@genepi1 bacula]# tapeinfo -f /dev/nst0 Product Type: Tape Drive Vendor ID: 'HP ' Product ID: 'Ultrium 4-SCSI ' Revision: 'B12H' Attached Changer API: No SerialNumber: 'HU17450M8L' MinBlock: 1 MaxBlock: 16777215 SCSI ID: 1 SCSI LUN: 0 Ready: yes BufferedMode: yes Medium Type: Not Loaded Density Code: 0x46 BlockSize: 16384 DataCompEnabled: yes DataCompCapable: yes DataDeCompEnabled: yes CompType: 0x1 DeCompType: 0x1 BOP: yes Block Position: 0 Partition 0 Remaining Kbytes: 799204 Partition 0 Size in Kbytes: 799204 ActivePartition: 0 EarlyWarningSize: 0 NumPartitions: 0 MaxPartitions: 0 On Thu, Dec 1, 2011 at 10:49 AM, <mark.berg...@uphs.upenn.edu> wrote: > In the message dated: Thu, 01 Dec 2011 16:27:33 GMT, > The pithy ruminations from Alan Brown on > <Re: [Bacula-users] tuning lto-4> were: > => gary artim wrote: > => > You guys/gals are great, very responsive! I did try > => > spooling/despooling and my run times shot up. > => > => They will - you're copying everything twice (disk to disk to tape), but > => this is the only way to achieve fast despooling speeds - if you don't do > => this then your LTO drive will start to "shoe shine" and speeds drop off > => rapidly when it happens. > > And you increase wear & tear on the drive and media. > > => > => The trick is to run multiple jobs at once - you have to spool to achieve > => this anyway or extracting will be a nightmare. > => > => Spooling is a net gain when you're running incrementals. > => > > Not necessarily. Spooling is a gain if you are measuring the speed > of writing to tape. Spooling may be a net loss for end-to-end (client > machine-->spool server-->tape drive) speed. > > For backups clients where the total volume being backed up is less than > the spool size, then there's a very good chance of a performance gain. As > soon as a job requires multiple rounds of spooling and de-spooling, > there's a good chance of a performance loss because bacula stops reading > from the client machine (stops spooling that job) as soon as despooling > begins. Of course, spooling allows you to run multiple jobs in parallel, a > clear win over running them in series. > > > See: > > [1] http://copilotco.com/mail-archives/bacula-devel.2007/msg02642.html > [2] > http://www.bacula.org/git/cgit.cgi/bacula/plain/bacula/projects?h=Branch-5.1 > > [3] > http://www.mail-archive.com/bacula-users@lists.sourceforge.net/msg49366.html > > > => Spooling MUST happen on a fast dedicated drive. You're best off dropping > => in a fast SSD such as a 64/128Gb OCZ vertex3 or similar to handle it. > > Hmm...for LTO4 (large spool files are good), you might want more space > than that, particularly if you have multiple clients (multiple spool > files). A more cost-effective option might be several fast drives (10K > or 15K SAS or SCSI) in RAID-0. It doesn't take very many drives in RAID0 to > have an aggregate drive throughput that is greater than the bus interface. > > => > => > I was using a simple > => > 7200 drive though, no ssd or raid...I assume the performance gain > > Yeah, the sustained read speed from a 7.2k RPM drive is lower than the > possible write speed to an LTO-4 drive: > > > http://www.seagate.com/www/en-us/support/before_you_buy/speed_considerations > > => > happens when your networks multi machines...wearing multiple hats so > => > will report back on btape next week, unless I get some time. gary > => > => Even on a single host, if the heads are thrashing then spooling will > => save time overall. The big advantage is being able to run multiple jobs > => so that several are spooling data at the same time one is despooling. > > Absolutely. Spooling is a big win for multiple jobs, and for reducing > wear&tear on the tape drive. It may or may not give a performance increase for > any single backup job. > > Mark > > ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
