Hello, On 5/28/19 8:03 AM, Oleksiy Evin wrote: > The linbit's article dated 2012 says the current maximum is 1PiB, but > when I'm trying to create a 3 node replication with 527TiB each, it > gets me to the bitmap size error. > > I have an assumption that overall bitmap size limit is divided for 2 > replicas.
An investigation of the issue in the source code of the current drbd-utils release 9.9.0 confirmed that you are right with your assumption. > Is there any technical reason behind it? We will have to discuss the issue internally, I believe that this is an unintentional limitation, possibly a left-over from DRBD 8.x code, since DRBD 8 was limited to a single peer, but please allow us some time to double-check whether or not removing this limitation causes any problems. > Is there any other way to create this volume without splitting it up > and joining by LVM on the top (LVM-> DRBD -> LVM)? Unfortunately, I do not think there is at this time. If we can determine that this limitation is unnecessary, then we will follow up with a new release of the drbd-utils that will fix this problem and allow the creation of larger volumes. > Can anyone please clarify what's the actual volume size limit for DRBD? With the current version of the drbd-utils (drbdmeta program), the actual limits I have calculated are: 1 peers: 1099510448128 kiB (~ 1,048,574.87 GiB) 2 peers: 549755224064 kiB (~ 524,287.43 GiB) 3 peers: 366503482624 kiB (~ 349,524.95 GiB) 4 peers: 274877612032 kiB (~ 262,143.71 GiB) 5 peers: 219902089472 kiB (~ 209,714.97 GiB) 6 peers: 183251741184 kiB (~ 174,762.47 GiB) 7 peers: 157072921088 kiB (~ 149,796.41 GiB) 8 peers: 137438806016 kiB (~ 131,071.85 GiB) 9 peers: 122167827456 kiB (~ 116,508.31 GiB) 10 peers: 109951044608 kiB (~ 104,857.48 GiB) 11 peers: 99955495168 kiB (~ 95,324.98 GiB) 12 peers: 91625870592 kiB (~ 87,381.23 GiB) 13 peers: 84577726720 kiB (~ 80,659.60 GiB) 14 peers: 78536460544 kiB (~ 74,898.20 GiB) 15 peers: 73300696320 kiB (~ 69,904.99 GiB) 16 peers: 68719403008 kiB (~ 65,535.92 GiB) 17 peers: 64677085184 kiB (~ 61,680.87 GiB) 18 peers: 61083913728 kiB (~ 58,254.15 GiB) 19 peers: 57868970752 kiB (~ 55,188.15 GiB) 20 peers: 54975522304 kiB (~ 52,428.74 GiB) 21 peers: 52357640192 kiB (~ 49,932.13 GiB) 22 peers: 49977747456 kiB (~ 47,662.49 GiB) 23 peers: 47804802048 kiB (~ 45,590.21 GiB) 24 peers: 45812935168 kiB (~ 43,690.61 GiB) 25 peers: 43980417792 kiB (~ 41,942.99 GiB) 26 peers: 42288863232 kiB (~ 40,329.80 GiB) 27 peers: 40722609152 kiB (~ 38,836.10 GiB) 28 peers: 39268230144 kiB (~ 37,499.10 GiB) 29 peers: 37914153216 kiB (~ 36,157.75 GiB) 30 peers: 36650348032 kiB (~ 34,952.49 GiB) 31 peers: 35468078848 kiB (~ 33,824.99 GiB) If in your case a volume size of 511 TiB would be sufficient, that should work with 2 peers. Best regards, Robert _______________________________________________ drbd-user mailing list [email protected] http://lists.linbit.com/mailman/listinfo/drbd-user
