Re: [ceph-users] Performance counters oddities, cache tier and otherwise

It seems that temperature / recency estimation haven't worked properly at some point. Cheers, Shinobu - Original Message - From: "Christian Balzer" To: ceph-users@lists.ceph.com Sent: Thursday, April 7, 2016 11:51:38 AM Subject: [ceph-users] Performance counters

Re: [ceph-users] adding cache tier in productive hammer environment

Hello, On Wed, 6 Apr 2016 20:35:20 +0200 Oliver Dzombic wrote: > Hi, > > i have some IO issues, and after Christian's great article/hint about > caches i plan to add caches too. > Thanks, version 2 is still a work in progress, as I keep running into unknowns. IO issues in what sense, like

[ceph-users] Performance counters oddities, cache tier and otherwise

Hello, Ceph 0.94.5 for the record. As some may remember, I phased in a 2TB cache tier 5 weeks ago. About now it has reached about 60% usage, which is what I have the cache_target_dirty_ratio set to. And for the last 3 days I could see some writes (op_in_bytes) to the backing storage (aka HDD

Re: [ceph-users] Maximizing OSD to PG quantity

Hello, On Wed, 6 Apr 2016 18:15:57 + David Turner wrote: > You can mitigate how much it affects the IO but for the cost of how long > it will take to complete. > > ceph tell osd.* injectargs '--osd-max-backfills #' > Also have a read of:

Re: [ceph-users] cephfs rm -rf on directory of 160TB /40M files

On Wed, Apr 6, 2016 at 10:42 PM, Scottix wrote: > I have been running some speed tests in POSIX file operations and I noticed > even just listing files can take a while compared to an attached HDD. I am > wondering is there a reason it takes so long to even just list files. If

Re: [ceph-users] cephfs rm -rf on directory of 160TB /40M files

On Wed, Apr 6, 2016 at 2:42 PM, Scottix wrote: > I have been running some speed tests in POSIX file operations and I noticed > even just listing files can take a while compared to an attached HDD. I am > wondering is there a reason it takes so long to even just list files. > >

Re: [ceph-users] cephfs rm -rf on directory of 160TB /40M files

I have been running some speed tests in POSIX file operations and I noticed even just listing files can take a while compared to an attached HDD. I am wondering is there a reason it takes so long to even just list files. Here is the test I ran time for i in {1..10}; do touch $i; done

[ceph-users] adding cache tier in productive hammer environment

Hi, i have some IO issues, and after Christian's great article/hint about caches i plan to add caches too. So now comes the troublesome question: How much dangerous is it to add cache tiers in an existing cluster with around 30 OSD's and 40 TB of Data on 3-6 ( currently reducing ) nodes. I

Re: [ceph-users] Maximizing OSD to PG quantity

You can mitigate how much it affects the IO but for the cost of how long it will take to complete. ceph tell osd.* injectargs '--osd-max-backfills #' Where # is the most pgs any osd can participate backfill data for at any given time. This is the same setting that is used when you add,

[ceph-users] Ceph Day Sunnyvale Presentations

Hey cephers, I have all but one of the presentations from Ceph Day Sunnyvale, so rather than wait for a full hand I went ahead and posted the link to the slides on the event page: http://ceph.com/cephdays/ceph-day-sunnyvale/ The videos probably wont be processed until after next week, but I’ll

Re: [ceph-users] Maximizing OSD to PG quantity

Will changing the replication size from 2 to 3 cause huge I/O resources to be used, or does this happen quietly in the background? On 2016-04-06 00:40, Christian Balzer wrote: Hello, Brian already mentioned a number very pertinent things, I've got a few more: On Tue, 05 Apr 2016 10:48:49

Re: [ceph-users] ceph rbd object write is atomic?

If you can guarantee that your write will be wholly contained within an object (and within a stripe), you should be able to consider the writes to be atomic between two clients since the OSD will process the two writes in sequence (all ops are execute in order for a given placement group). --

Re: [ceph-users] ceph rbd object write is atomic?

Thanks Jason, yes, I also do not think they can guarantee atomic in extent level. But for a stripe unit in a object, can the atomic write be guaranteed? thanks. 2016-04-06 19:53 GMT+08:00 Jason Dillaman : > It's possible for a write to span one or more blocks -- it just