… that’s maybe just normal. We didn’t try too hard to get better performance because we already had more than… data will compress much more. That gives us much more disk space than we expected so even more snapshots! Integrity With… from the other drive in the mirror. Better availability and disk usage On purpose, I allocated mirror pairs using drives from…
Post: MySQL 5.6 Compatible Percona Toolkit 2.2 Released
March 25, 2013 By 2 Comments
… make it “try harder”, even though it already tried pretty hard to keep working despite recoverable errors and such. Whereas pt… highly configurable, so you can make the tool try very hard to keep working. pt-upgrade is brand-new pt-upgrade… on a server. Granted, this can take a lot of disk space, but it allows you to “run now, compare later…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 18 Comments
… had were rotating hard disk drives. I think the reason is very simple – when systems only had one bearing hard disk drive (HDD) as in RAID1 or one disk drive at all, you couldn’t really… decide on very early when configuring RAID. Disk sectors Most if not all hard disk drives available on the market these days use…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
… Size ========== ==== ======= ====== ======= ============ =========== Hard Disk SAS Online 0/0/0 SEAGATE ST3600057SS 558.911 Hard Disk SAS Online 0/0/0 SEAGATE ST3600057SS 558.911 Hard Disk SAS Online 0/0/0 SEAGATE ST3600057SS 558.911 Hard Disk SAS…
Post: InnoDB Flushing: a lot of memory and slow disk
March 31, 2011 By 57 Comments
… problem here is that the system has quite slow hard drives (2 hard disks in software RAID0). As you can see, after the… makes calculating how many pages we need to flush extremely hard (read “impossible”), and this is one of the reasons why…)? Well, it may help to some extent, but remember that hard disks love sequential operations, and your throughput in this case may…
Post: How multiple disks can benefit for single client workload ?
April 26, 2008 By 4 Comments
… necessary means single outstanding disk IO request at all times. So natively it can benefit from multiple hard drives this way. But… take N tracks on this disk. Now if we stripe the same data among couple of hard drives it will take N… will be far from sequential disk access performance. First you should consider what has to happen with hard drive to read/write…
Post: Is disk Everything for MySQL Performance ?
April 25, 2008 By 7 Comments
… many systems they have” on MySQL UC2008 Scalability Panel ? Indeed disks MAY be the most important part in your system performance… always the case. There are whole classes of systems where Disk performance is not that important – consider for example systems where… serialization issues along you need enough concurrency to utilize multiple hard drives and with 50 drives you would need at least…
Comment: InnoDB Flushing: a lot of memory and slow disk
April 1, 2011 By 57 Comments
… it comes to rotating disks. For blocks physically close to each other, head move isn’t necessary, the hard drive only has… on the whole hard disk, and run the same benchmark again on a small partition at the beginning of the disk. The number… with a sequential io benchmark too, the beginning of the disk will be always faster, you can see “steps pattern” when…
Comment: InnoDB Flushing: a lot of memory and slow disk
March 31, 2011 By 57 Comments
… it comes to rotating disks. For blocks physically close to each other, head move isn’t necessary, the hard drive only has… on the whole hard disk, and run the same benchmark again on a small partition at the beginning of the disk. The number… with a sequential io benchmark too, the beginning of the disk will be always faster, you can see “steps pattern” when…
Comment: Finding out largest tables on MySQL Server
April 24, 2012 By 27 Comments
… these queries compare to the size of the tables on disk? For example, using file_per_table, if the total_size… a good opportunity to run OPTIMIZE and thus reclaim some hard disk space? Taking real-world data, I have for example a… mysql 58G 2012-04-24 13:41 tablename.ibd On disk vs the information_schema query, there is around 9GB discrepancy…
