Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
On Mon, Oct 24, 2011 at 10:23 PM, David Boreham david_l...@boreham.orgwrote: A few quick thoughts: 1. 320 would be the only SSD I'd trust from your short-list. It's the only one with proper protection from unexpected power loss. 2. Multiple RAID'ed SSDs sounds like (vast) overkill for your workload. A single SSD should be sufficient (will get you several thousand TPS on pgbench for your DB size). 3. Consider not using the magnetic disks at all (saves on space, power and the cost of the RAID controller for them). 4. Consider using Intel 710 series rather than 320 (pay for them with the money saved from #3 above). Those devices have much, much higher specified endurance than the 320s and since your DB is quite small you only need to buy one of them. On 10/24/2011 8:09 AM, Amitabh Kant wrote: Hello I need to choose between Intel 320 , Intel 510 and OCZ Vertex 3 SSD's for my database server. From recent reading in the list and other places, I have come to understand that OCZ Vertex 3 should not be used, Intel 510 uses a Marvel controller while Intel 320 had a nasty bug which has been rectified. So the list narrows down to only 510 and 320, unless I have understood the OCZ Vertex reviews incorrectly. The server would itself be built along these lines: Dual CPU Xeon 5620, 32 or 48 GB RAM, 2 SAS 10K disk in RAID 1 for OS, 2 SAS 10K disk in RAID 1 for pg_xlog and 4 SSD in RAID 10 for data directory (overkill??). OS would be FreeBSD 8.2 (I would be tuning the sysctl variables). PG version would be 9.1 with replication set to another machine (Dual CPU Xeon 54xx, 32 GB RAM, 6 15K SAS 146 GB: 4 in RAID 10 for data and 2 in RAID 1 for OS + pg_xlog). The second machine hosts my current db , and there is not much of an issue with the performance. We need better redundancy now(current was to take a dump/backup every 12 hours), so the new machine. My database itself is not very big, approx 40 GB as of now, and would not grow beyond 80 GB in the next year or two. There are some tables where insert updates are fairly frequent. From what I could gather, we are not doing more than 300-400 tps at the moment, and the growth should not be very high in the short term. Hope someone can give some pointers to which SSD I should go for at the moment. Amitabh Sadly, 710 is not that easily available around here at the moment. Amitabh
Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
On 10/28/2011 12:40 AM, Amitabh Kant wrote: Sadly, 710 is not that easily available around here at the moment. All three sizes are in stock at newegg.com, if you have a way to export from the US to your location. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
Am 24.10.2011 16:09, schrieb Amitabh Kant: while Intel 320 had a nasty bug which has been rectified Be careful with that Intel SSD. This one is still very buggy. Take a look at the Intel forums http://communities.intel.com/community/tech/solidstate?view=discussions#/ about users who are complaining that they´ve lost all their data. Even the firmware upgrade didn´t completely resolved the issues. Regards Thilo -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
On Mon, Oct 24, 2011 at 11:37 PM, David Boreham david_l...@boreham.org wrote: What about redundancy? How do you swap an about-to-die SSD? Software RAID-1? The approach we take is that we use 710 series devices which have predicted reliability similar to all the other components in the machine, therefore the unit of replacement is the entire machine. We don't use trays for example (which saves quite a bit on data center space). If I were running short endurance devices such as 320 series I would be interested in replacing the drives before the machine itself is likely to fail, but I'd do so by migrating the data and load to another machine for the replacement to be done offline. Note that there are other operations procedures that need to be done and can not be done without downtime (e.g. OS upgrade), so some kind of plan to deliver service while a single machine is down for a while will be needed regardless of the storage device situation. Interesting. But what about unexpected failures. Faulty electronics, stuff like that? I really don't think a production server can work without at least raid-1. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
On 10/25/2011 8:55 AM, Claudio Freire wrote: But what about unexpected failures. Faulty electronics, stuff like that? I really don't think a production server can work without at least raid-1. Same approach : a server either works or it does not. The transition between working and not working may be expected or not expected. The solution is the same : use another machine to perform the work the now not working machine was doing. The big benefit of this approach is that you now do not need to worry about specific kinds of failure or individual components, including storage. If it helps, think of this architecture as raid-1, but with the whole machine being the drive rather than individual storage devices. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
A few quick thoughts: 1. 320 would be the only SSD I'd trust from your short-list. It's the only one with proper protection from unexpected power loss. 2. Multiple RAID'ed SSDs sounds like (vast) overkill for your workload. A single SSD should be sufficient (will get you several thousand TPS on pgbench for your DB size). 3. Consider not using the magnetic disks at all (saves on space, power and the cost of the RAID controller for them). 4. Consider using Intel 710 series rather than 320 (pay for them with the money saved from #3 above). Those devices have much, much higher specified endurance than the 320s and since your DB is quite small you only need to buy one of them. On 10/24/2011 8:09 AM, Amitabh Kant wrote: Hello I need to choose between Intel 320 , Intel 510 and OCZ Vertex 3 SSD's for my database server. From recent reading in the list and other places, I have come to understand that OCZ Vertex 3 should not be used, Intel 510 uses a Marvel controller while Intel 320 had a nasty bug which has been rectified. So the list narrows down to only 510 and 320, unless I have understood the OCZ Vertex reviews incorrectly. The server would itself be built along these lines: Dual CPU Xeon 5620, 32 or 48 GB RAM, 2 SAS 10K disk in RAID 1 for OS, 2 SAS 10K disk in RAID 1 for pg_xlog and 4 SSD in RAID 10 for data directory (overkill??). OS would be FreeBSD 8.2 (I would be tuning the sysctl variables). PG version would be 9.1 with replication set to another machine (Dual CPU Xeon 54xx, 32 GB RAM, 6 15K SAS 146 GB: 4 in RAID 10 for data and 2 in RAID 1 for OS + pg_xlog). The second machine hosts my current db , and there is not much of an issue with the performance. We need better redundancy now(current was to take a dump/backup every 12 hours), so the new machine. My database itself is not very big, approx 40 GB as of now, and would not grow beyond 80 GB in the next year or two. There are some tables where insert updates are fairly frequent. From what I could gather, we are not doing more than 300-400 tps at the moment, and the growth should not be very high in the short term. Hope someone can give some pointers to which SSD I should go for at the moment. Amitabh -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
On Mon, Oct 24, 2011 at 11:53 AM, David Boreham david_l...@boreham.org wrote: A few quick thoughts: 1. 320 would be the only SSD I'd trust from your short-list. It's the only one with proper protection from unexpected power loss. yeah. 2. Multiple RAID'ed SSDs sounds like (vast) overkill for your workload. A single SSD should be sufficient (will get you several thousand TPS on pgbench for your DB size). Also, raid controllers interfere with TRIM. 3. Consider not using the magnetic disks at all (saves on space, power and the cost of the RAID controller for them). Agree. If one SSD did not deliver the tps, I'd consider buying more and optimizing with jbod/tablespaces -- really doubt that's necessary however. Maybe a single large slow magnetic disk is a good idea for retaining backups though. 4. Consider using Intel 710 series rather than 320 (pay for them with the money saved from #3 above). Those devices have much, much higher specified endurance than the 320s and since your DB is quite small you only need to buy one of them. 710 is good idea if and only if you are worried about write durability (in which case it's a great idea). merlin -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
On Mon, Oct 24, 2011 at 6:31 PM, Merlin Moncure mmonc...@gmail.com wrote: 2. Multiple RAID'ed SSDs sounds like (vast) overkill for your workload. A single SSD should be sufficient (will get you several thousand TPS on pgbench for your DB size). Also, raid controllers interfere with TRIM. What about redundancy? How do you swap an about-to-die SSD? Software RAID-1? -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
On 10/24/2011 3:31 PM, Merlin Moncure wrote: 4. Consider using Intel 710 series rather than 320 (pay for them with the money saved from #3 above). Those devices have much, much higher specified endurance than the 320s and since your DB is quite small you only need to buy one of them. 710 is good idea if and only if you are worried about write durability (in which case it's a great idea). I disagree with this (that it is the only reason to select 710 series). The write endurance (specified at least) is orders of magnitude higher. Doing 100's of TPS constantly it is possible to burn through the 320's endurance lifetime in a year or two. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Choosing between Intel 320, Intel 510 or OCZ Vertex 3 SSD for db server
On 10/24/2011 4:47 PM, Claudio Freire wrote: What about redundancy? How do you swap an about-to-die SSD? Software RAID-1? The approach we take is that we use 710 series devices which have predicted reliability similar to all the other components in the machine, therefore the unit of replacement is the entire machine. We don't use trays for example (which saves quite a bit on data center space). If I were running short endurance devices such as 320 series I would be interested in replacing the drives before the machine itself is likely to fail, but I'd do so by migrating the data and load to another machine for the replacement to be done offline. Note that there are other operations procedures that need to be done and can not be done without downtime (e.g. OS upgrade), so some kind of plan to deliver service while a single machine is down for a while will be needed regardless of the storage device situation. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
