Re: [PERFORM] Tuning guidelines for server with 256GB of RAM and SSDs?

2016-07-07 Thread Wes Vaske (wvaske)
?The Crucial drive does not have power loss protection. The Samsung drive does. (The Crucial M550 has capacitors to protect data that's already been written to the device but not the entire cache. For instance, if data is read from the device during a garbage collection operation, the M550

Re: [PERFORM] Tuning guidelines for server with 256GB of RAM and SSDs?

2016-07-07 Thread Merlin Moncure
On Wed, Jul 6, 2016 at 4:48 PM, Scott Marlowe wrote: > On Wed, Jul 6, 2016 at 12:13 PM, Merlin Moncure wrote: >> Disabling write back cache for write heavy database loads will will >> destroy it in short order due to write amplication and will

Re: [PERFORM] Tuning guidelines for server with 256GB of RAM and SSDs?

2016-07-07 Thread Scott Marlowe
On Thu, Jul 7, 2016 at 10:27 AM, Merlin Moncure wrote: > On Wed, Jul 6, 2016 at 4:48 PM, Scott Marlowe wrote: >> On Wed, Jul 6, 2016 at 12:13 PM, Merlin Moncure wrote: >>> Disabling write back cache for write heavy database loads

Re: [PERFORM] Tuning guidelines for server with 256GB of RAM and SSDs?

2016-07-07 Thread Kaixi Luo
It's a Crucial CT250MX200SSD1 and a Samsung MZ7LM480HCHP-3. Regards, Kaixi On Thu, Jul 7, 2016 at 6:59 AM, Mark Kirkwood wrote: > On 06/07/16 07:17, Mkrtchyan, Tigran wrote: > >> Hi, >> >> We had a similar situation and the best performance was with 64MB

Re: [PERFORM] DELETE takes too much memory

2016-07-07 Thread Kouber Saparev
I was using the pg_activity monitoring tool, which I find quite awesome. https://github.com/julmon/pg_activity There are 3 btree indexes, here's the definition of the table itself: Table "audits.audits" Column |Type

Re: [PERFORM] Tuning guidelines for server with 256GB of RAM and SSDs?

2016-07-07 Thread Kaixi Luo
> Regarding write back cache: > Disabling the write back cache won't have a real large impact on the > endurance of the drive unless it reduces the total number of bytes written > (which it won't). I've seen drives that perform better with it disabled and > drives that perform better with it

Re: [PERFORM] Tuning guidelines for server with 256GB of RAM and SSDs?

2016-07-07 Thread Mark Kirkwood
On 08/07/16 02:09, Wes Vaske (wvaske) wrote: ?The Crucial drive does not have power loss protection. The Samsung drive does. (The Crucial M550 has capacitors to protect data that's already been written to the device but not the entire cache. For instance, if data is read from the device