> -----Original Message----- > From: Fred Liu > Sent: 星期三, 三月 09, 2016 13:02 > To: smartos-discuss@lists.smartos.org > Cc: illumos-developer > Subject: RE: [smartos-discuss] Samsung 950 Pro on SmartOS? > > > > From: Dirk Steinberg [mailto:d...@steinbergnet.net] > Sent: 星期三, 三月 09, 2016 0:06 > To: smartos-discuss@lists.smartos.org > Subject: Re: [smartos-discuss] Samsung 950 Pro on SmartOS? > > > Am 07.03.2016 um 06:48 schrieb Fred Liu <fred.f...@gmail.com>: > > > 2016-03-05 21:19 GMT+08:00 Dirk Steinberg <d...@steinbergnet.net>: > > Apart from that: is NVMe support in SmartOS considered stable? > > > There is driver support for it in the system. I have not heard many > reports positively or negatively about it. > > [Fred]: I am testing some Intel P3600 NVMe SSD. In normal workload, they just > work . But in burning mode like continuous scrubbings, I have got lots of > checksum errors. And I tested the same scrubbings under Linux, no checksum > errors were found. > Fred > > Hi Fred, > > do you attribute these errors to the SmartOS NVMe driver? > Sounds like it since you are saying that the same SSD works under Linux. > > So have you given up on NVMe on SmartOS? > > [Fred]: I personally attribute those errors to the immaturity of the NVMe > driver > in Illumos. But that is not so severe based on the fact that there are no > substantial data loss with those checksum errors. > I used to get some some kernel panics under "too may check sum erros" and > after disabling "sha512|skeun|edonr" checksum algorithm, the server has > been running well for more than two weeks. > It looks like "sha512|skeun|edonr" checksum algorithm still has some glitches. > > Thanks. >
[Fred]: With the patch 7321 (https://www.illumos.org/issues/7312), I can confirm these checksum errors are all gone. Thanks. Fred > > Sorry, I am not quite sure what you are trying to tell me. > > I am running the sha512 hash on a regular disk pool without problems. I have > also > run a number of scrubs. I assume the the sha512 hash is working correctly. > If I had a ton of checksum errors from ZFS I would be VERY concerned. > Just turning off the checksum may not be the solution… > I do not think that a bug in sha512 is generating these. > > Also, what do you mean by „no substantial data loss“? Either there is > data loss or there is no data loss. My policy here is that even a single > bit of data loss is not acceptable. This is why ZFS goes to all the > effort of using strong checksums and redundancy and scrubbing and so on… > > If you are willing to accept „some nonsubstantial data loss“ and turn > of checksums so as not to be bothered by all these checksum errors > there is not much point in using ZFS in the first place! > > Am I understanding something incorrectly? > > [Fred]: "NVMe support" and "[sha512|skein|edonr] hash algorithm" are the > major spot-lights > of Illumos in 2015. I am running 20160218T022556Z now. Disabling > "sha512|skein|edonr" > doesn't mean setting "checksum=off". In default("checksum=on"), > zfs automatically > selects an appropriate algorithm if these > features("[sha512|skein|edonr]") are enabled. > I met random server reboots(triggered by zfs deadman) and panics. > But I could not get > the nitty-gritty reason from core dump. And we do have very stable > running of release of > 2014. To reason by exclusive method, I recreated the zpool and set > "checksum=sha256". And > till now the server has been running well at least for two weeks. > This operation does > not intend to remove the *annoying* checksum errors. > As for "no substantial data loss", that means "zpool status" always > show "errors: No known data errors" even with "too many checksum errors". > > Thanks. > > Fred ------------------------------------------- smartos-discuss Archives: https://www.listbox.com/member/archive/184463/=now RSS Feed: https://www.listbox.com/member/archive/rss/184463/25769125-55cfbc00 Modify Your Subscription: https://www.listbox.com/member/?member_id=25769125&id_secret=25769125-7688e9fb Powered by Listbox: http://www.listbox.com
