Hello Shreyansh Shah, I’m assuming you configured this as a test system, since there’s no redundancy in this setup? From my own experience I’d say that gluster tries to fill bricks evenly, i.e. the 10TB disk should get 2.5 times more data than the 4TB disk in a perfect world with lots of smallish files. I say “should”, because this really depends on the hashing algorithm that Gluster uses to decide on where to store a file. If you have lots of little files, you’ll get a good distribution across all disks. If you have large files, however, you might end up with several of them put together on the smallest drive. That might happen when you rebalance, too.
There is an option – feature.sharding - to split large files into smaller parts (“shards”) that are then in turn distributed across the bricks in your gluster. It might help with overfilling on your smaller drives. However, at least until Gluster 7.9 it was severely broken in that delete operations didn’t actually delete all of the shards that were allocated for large files.
As for rebalance breaking down – yeah, been there, done that. We were in the unenviable position of having to add two more nodes to a 4x2 distribute-replicate gluster of about 60TB with ~ 150M of small files. Rebalancing took 5 weeks, mainly because we had to restart it twice. Best regards, i.A. Thomas Bätzler -- BRINGE Informationstechnik GmbH Zur Seeplatte 12 D-76228 Karlsruhe Germany Fon: +49 721 94246-0 Fon: +49 171 5438457 Fax: +49 721 94246-66 Web: http://www.bringe.de/ Geschäftsführer: Dipl.-Ing. (FH) Martin Bringe Ust.Id: DE812936645, HRB 108943 Mannheim Von: Shreyansh Shah <shreyansh.shah@xxxxxxxxxxxxxx>
Gesendet: Freitag, 12. November 2021 08:42
An: Thomas Bätzler <t.baetzler@xxxxxxxxxx>
Cc: gluster-users <gluster-users@xxxxxxxxxxx>
Betreff: Re: Rebalance Issues Hi Thomas,
Thank you for your response. Adding the required info below: Volume Name: data
Type: Distribute
Volume ID: 75410231-bb25-4f14-bcde-caf18fce1d31
Status: Started
Snapshot Count: 0
Number of Bricks: 35
Transport-type: tcp
Bricks:
Brick1: 10.132.1.12:/data/data
Brick2: 10.132.1.12:/data1/data
Brick3: 10.132.1.12:/data2/data
Brick4: 10.132.1.12:/data3/data
Brick5: 10.132.1.13:/data/data
Brick6: 10.132.1.13:/data1/data
Brick7: 10.132.1.13:/data2/data
Brick8: 10.132.1.13:/data3/data
Brick9: 10.132.1.14:/data3/data
Brick10: 10.132.1.14:/data2/data
Brick11: 10.132.1.14:/data1/data
Brick12: 10.132.1.14:/data/data
Brick13: 10.132.1.15:/data/data
Brick14: 10.132.1.15:/data1/data
Brick15: 10.132.1.15:/data2/data
Brick16: 10.132.1.15:/data3/data
Brick17: 10.132.1.16:/data/data
Brick18: 10.132.1.16:/data1/data
Brick19: 10.132.1.16:/data2/data
Brick20: 10.132.1.16:/data3/data
Brick21: 10.132.1.17:/data3/data
Brick22: 10.132.1.17:/data2/data
Brick23: 10.132.1.17:/data1/data
Brick24: 10.132.1.17:/data/data
Brick25: 10.132.1.18:/data/data
Brick26: 10.132.1.18:/data1/data
Brick27: 10.132.1.18:/data2/data
Brick28: 10.132.1.18:/data3/data
Brick29: 10.132.1.19:/data3/data
Brick30: 10.132.1.19:/data2/data
Brick31: 10.132.1.19:/data1/data
Brick32: 10.132.1.19:/data/data
Brick33: 10.132.0.19:/data1/data
Brick34: 10.132.0.19:/data2/data
Brick35: 10.132.0.19:/data/data
Options Reconfigured:
performance.cache-refresh-timeout: 60
performance.cache-size: 8GB
transport.address-family: inet
nfs.disable: on
performance.client-io-threads: on
storage.health-check-interval: 60
server.keepalive-time: 60
client.keepalive-time: 60
network.ping-timeout: 90
server.event-threads: 2 Hello Shreyansh Shah, How is your gluster set up? I think it would be very helpful for our understanding of your setup to see the output of “gluster v info all” annotated with brick sizes.
Otherwise, how could anybody answer your questions? Best regards, i.A. Thomas Bätzler -- BRINGE Informationstechnik GmbH Zur Seeplatte 12 D-76228 Karlsruhe Germany Fon: +49 721 94246-0 Fon: +49 171 5438457 Fax: +49 721 94246-66 Web: http://www.bringe.de/ Geschäftsführer: Dipl.-Ing. (FH) Martin Bringe Ust.Id: DE812936645, HRB 108943 Mannheim Hi All,
I have a distributed glusterfs 5.10 setup with 8 nodes and each of them having 1 TB disk and 3 disk of 4TB each (so total 22 TB per node).
Recently I added a new node with 3 additional disks (1 x 10TB + 2 x 8TB). Post this I ran rebalance and it does not seem to complete successfully (adding result of gluster volume rebalance data status below). On a few nodes it shows failed and on the node it is showing as completed the rebalance is not even. root@gluster6-new:~# gluster v rebalance data status
Node Rebalanced-files size scanned failures skipped status run time in h:m:s
--------- ----------- ----------- ----------- ----------- ----------- ------------ --------------
localhost 22836 2.4TB 136149 1 27664 in progress 14:48:56
10.132.1.15 80 5.0MB 1134 3 121 failed 1:08:33
10.132.1.14 18573 2.5TB 137827 20 31278 in progress 14:48:56
10.132.1.12 607 61.3MB 1667 5 60 failed 1:08:33
gluster4.c.storage-186813.internal 26479 2.8TB 148402 14 38271 in progress 14:48:56
10.132.1.18 86 6.4MB 1094 5 70 failed 1:08:33
10.132.1.17 21953 2.6TB 131573 4 26818 in progress 14:48:56
10.132.1.16 56 45.0MB 1203 5 111 failed 1:08:33
10.132.0.19 3108 1.9TB 224707 2 160148 completed 13:56:31
Estimated time left for rebalance to complete : 22:04:28
Adding 'df -h' output for the node that has been marked as completed in the above status command, the data does not seem to be evenly balanced.
root@gluster-9:~$ df -h /data*
Filesystem Size Used Avail Use% Mounted on
/dev/bcache0 10T 8.9T 1.1T 90% /data
/dev/bcache1 8.0T 5.0T 3.0T 63% /data1
/dev/bcache2 8.0T 5.0T 3.0T 63% /data2
I would appreciate any help to identify the issues here:
1. Failures during rebalance.
2. Im-balance in data size post gluster rebalance command. 3. Another thing I would like to mention is that we had to re-balance twice as in the initial run one of the new disks on the new node (10 TB), got 100% full. Any thoughts as to why this could happen during rebalance? The disks on the new node were completely blank disks before rebalance.
4. Does glusterfs rebalance data based on percentage used or absolute free disk space available?
I can share more details/logs if required. Thanks. -- Regards,
Shreyansh Shah AlphaGrep Securities Pvt. Ltd.
-- Regards,
Shreyansh Shah AlphaGrep Securities Pvt. Ltd. |
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