Firebird и база на SSD диске

Встретилось в fb-devel интересное сообщение, о переходе на SSD диск. Если кратко - то значительно увеличилась производительность при большой загрузке дисковой подсистемы, когда основное время тратится на позиционирование головок диска при большом потоке конкурентных обращений.

"Если на обычном 5-то рейде в таких ситуация(более 1000 коннектов) ответ ждали до минуты, то в ssd это время оставалось константным, порядка 4сек."

Естественно не для всяких систем это будет верно, но все же...

Hi Pays,

I can't give you exact figures, but we switched

from
HP 585 4 processor AMD Opteron 850/16GB with raid5 HP SCSI Ultra320 15krpm 8
disk array for the DB

to
HP 385 2 x quad core AMD Opteron 2384 and an FusionIO IODrive, an 80GB SSD
formatted as 40GB so it can continously prepare the remaining 40GB for write
operations which gives it a performance advantage.

The performance gain was noticable. We are btw running FB2.1 classic, AMD 2
x quad core/20GB ram. A "big" query taking around 8 seconds on the SCSI took
only 4 seconds on the FusionIO. Thus the pure performance gain was just
around 2 times faster. It was a query primarily putting load on the disks,
not the CPU, so I guess the new and better server hardware didn't influence
the result too much.

But the really interesting part comes under higher load! As there is no
latency in positioning the heads on a SSD, it really doesn't seem to care
about number of connections (at least not in our case). So where the SCSI
raid dramatically dropped performance and went to around one minute for the
above query during heavy load (>1000 connections), the SSD still answered in
4 seconds. That makes all the difference to us - and not least our users :)

I hope you can use the above informations in your research. Only
disadvantage for the IODrive, at least for now, is that it isn't mounted
until the server loads the drivers for it. So you can't really boot from it.

Kind regards

Poul Dige
Tabulex