William Ferrell
2019-Sep-25 12:32 UTC
[Gluster-users] Add single brick to dispersed volume?
Hello, I'm just getting started with GlusterFS, so please forgive what's probably a newbie question. I searched the mailing list archives and didn't see anything about this, so I figured I'd just ask. I'm running four VMs on a single machine to learn the ropes a little bit. Each VM is set up the same way, with an OS disk and a separate disk (formatted as xfs) for use as a brick. Initially I created a dispersed volume using three bricks with replication 1. That seems to work pretty well. Now I'm trying to add a fourth brick to the volume, but am receiving an error when I try: root at gluster1:~# gluster volume add-brick test1 gluster4:/export/gfs/brick volume add-brick: failed: Incorrect number of bricks supplied 1 with count 3 Have I misunderstood how dispersed volumes work? I was under the impression (from the documentation at https://docs.gluster.org/en/latest/Administrator%20Guide/Managing%20Volumes/#expanding-volumes) that bricks could be added to dispersed volumes so long as they were added N at a time, where N is the replication value. This error message makes it sound like I need to add three bricks at once instead. Is it possible to expand dispersed volumes like this? Or would I be better off doing this with a "regular" replicated volume? I'm interested in using dispersed volumes because of the space savings, but I'm a bit confused about how expansion works for them. Thanks for you help!
Hi William, If you want to increase capacity of a disperse volume, you have to add bricks to your existing disperse volume. The number of bricks you add should be in multiple of the existing configuration. For example: If you have created a disperse volume like this - gluster volume create myvol disperse 3 redundancy 1 host1:brick1 host2:brick2 host3:brick3 This is a 1 x (2+1) disperse volume. Now if you want to add some bricks to this volume, you have to do following - gluster volume add-brick myvol host1:brick11 host2:brick22 host3:brick33 which will add 3 bricks in the form of one new sub volume - 2 x (2+1) or you can do this gluster volume add-brick myvol host1:brick11 host2:brick22 host3:brick33 host1:brick111 host2:brick222 host3:brick333 which will add 6 bricks in the form of two new sub volume - 3 x (2+1) You mixed replication and disperse words so I am not sure which type of volume you have created. However, for replica volume also you have to add bricks in multiple. In these type of queries, it would be better to provide information about volumes which would help us to understand your questions. gluster v <volume name> info gluster v <volume name> status --- Ashish ----- Original Message ----- From: "William Ferrell" <willfe at gmail.com> To: gluster-users at gluster.org Sent: Wednesday, September 25, 2019 6:02:37 PM Subject: [Gluster-users] Add single brick to dispersed volume? Hello, I'm just getting started with GlusterFS, so please forgive what's probably a newbie question. I searched the mailing list archives and didn't see anything about this, so I figured I'd just ask. I'm running four VMs on a single machine to learn the ropes a little bit. Each VM is set up the same way, with an OS disk and a separate disk (formatted as xfs) for use as a brick. Initially I created a dispersed volume using three bricks with replication 1. That seems to work pretty well. Now I'm trying to add a fourth brick to the volume, but am receiving an error when I try: root at gluster1:~# gluster volume add-brick test1 gluster4:/export/gfs/brick volume add-brick: failed: Incorrect number of bricks supplied 1 with count 3 Have I misunderstood how dispersed volumes work? I was under the impression (from the documentation at https://docs.gluster.org/en/latest/Administrator%20Guide/Managing%20Volumes/#expanding-volumes) that bricks could be added to dispersed volumes so long as they were added N at a time, where N is the replication value. This error message makes it sound like I need to add three bricks at once instead. Is it possible to expand dispersed volumes like this? Or would I be better off doing this with a "regular" replicated volume? I'm interested in using dispersed volumes because of the space savings, but I'm a bit confused about how expansion works for them. Thanks for you help! ________ Community Meeting Calendar: APAC Schedule - Every 2nd and 4th Tuesday at 11:30 AM IST Bridge: https://bluejeans.com/118564314 NA/EMEA Schedule - Every 1st and 3rd Tuesday at 01:00 PM EDT Bridge: https://bluejeans.com/118564314 Gluster-users mailing list Gluster-users at gluster.org https://lists.gluster.org/mailman/listinfo/gluster-users -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.gluster.org/pipermail/gluster-users/attachments/20190925/81f79216/attachment.html>