On 02/10/12 01:35, Stephen Thompson wrote: > > > Correction, the non-problem drive has a higher "ECC fast" error count, > but the problem drive has a significantly higher "Corrective algorithm > invocations" count. >
What that means is that it rewrote the data, which accounts for the lower throughput. LTO drives read as they write and if there are errors, they write again. If a cleaning tape doesn't work then you need to get the drive looked at/replaced under warranty. > On 10/1/12 5:33 PM, Stephen Thompson wrote: >> >> On 10/1/12 4:06 PM, Alan Brown wrote: >>> On 01/10/12 23:38, Stephen Thompson wrote: >>>> More importantly, I realized that my testing 6 months ago was not on >>>> all 4 of my drives, but only 2 of them. Today, I discovered one of my >>>> drives (untested in the past) is getting 1/2 the throughput for random >>>> data writes as the others!! >>> "smartctl -a /dev/sg(drive)" will tell you a lot >>> >>> Put a cleaning tape in it.... >>> >>> >>> >>> >>> >> >> Cleaning tape did not improve results. >> >> I see some errors in the counter log on the problem drive, but I see >> even more errors on another drive which isn't having a throughput >> problem (specifically SL500 Drive 1 is the lower throughput, but C4 >> Drive 1 actually has a higher error count). >> >> >> >> SL500 Drive 0 (~60MB/s random data throughput) >> ============= >> Error counter log: >> Errors Corrected by Total Correction >> Gigabytes Total >> ECC rereads/ errors algorithm >> processed uncorrected >> fast | delayed rewrites corrected invocations [10^9 >> bytes] errors >> read: 0 0 0 0 0 0.000 >> 0 >> write: 0 0 0 0 0 0.000 >> 0 >> >> >> SL500 Drive 1 (~30MB/s random data throughput) >> ============= >> Error counter log: >> Errors Corrected by Total Correction >> Gigabytes Total >> ECC rereads/ errors algorithm >> processed uncorrected >> fast | delayed rewrites corrected invocations [10^9 >> bytes] errors >> read: 0 0 0 0 0 0.000 >> 0 >> write: 10454 0 0 0 821389 0.000 >> 0 >> >> >> C4 Drive 0 (~60MB/s random data throughput) >> ========== >> Error counter log: >> Errors Corrected by Total Correction >> Gigabytes Total >> ECC rereads/ errors algorithm >> processed uncorrected >> fast | delayed rewrites corrected invocations [10^9 >> bytes] errors >> read: 2 0 0 0 2 0.000 >> 0 >> write: 0 0 0 0 0 0.000 >> 0 >> >> >> C4 Drive 1 (~60MB/s random data throughput) >> ========== >> Error counter log: >> Errors Corrected by Total Correction >> Gigabytes Total >> ECC rereads/ errors algorithm >> processed uncorrected >> fast | delayed rewrites corrected invocations [10^9 >> bytes] errors >> read: 2 0 0 0 2 0.000 >> 0 >> write: 18961 0 0 0 48261 0.000 >> 0 >> >> >> >> >> Stephen >> ------------------------------------------------------------------------------ Don't let slow site performance ruin your business. Deploy New Relic APM Deploy New Relic app performance management and know exactly what is happening inside your Ruby, Python, PHP, Java, and .NET app Try New Relic at no cost today and get our sweet Data Nerd shirt too! http://p.sf.net/sfu/newrelic-dev2dev _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
