Bug 1277112
| Summary: | Data Tiering:File create and new writes to existing file fails when the hot tier is full instead of redirecting/flushing the data to cold tier | ||
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| Product: | [Red Hat Storage] Red Hat Gluster Storage | Reporter: | Nag Pavan Chilakam <nchilaka> |
| Component: | tier | Assignee: | Nithya Balachandran <nbalacha> |
| Status: | CLOSED WONTFIX | QA Contact: | Nag Pavan Chilakam <nchilaka> |
| Severity: | urgent | Docs Contact: | |
| Priority: | urgent | ||
| Version: | rhgs-3.1 | CC: | asrivast, jbyers, nbalacha, rcyriac, rgowdapp, rhinduja, rhs-bugs, sankarshan, smohan, vnosov |
| Target Milestone: | --- | Keywords: | Reopened, ZStream |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | tier-migration | ||
| Fixed In Version: | Doc Type: | Known Issue | |
| Doc Text: |
When hot tier storage is full, write operations such as file creation or new writes to existing files fail with a 'No space left on device' error, instead of redirecting writes or flushing data to cold tier storage.
Workaround: If the hot tier is not completely full, it is possible to work around this issue by waiting for the next CTR promote/demote cycle before continuing with write operations.
If the hot tier does fill completely, administrators can copy a file from the hot tier to a safe location, delete the original file from the hot tier, and wait for demotion to free more space on the hot tier before copying the file back.
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Story Points: | --- |
| Clone Of: | 1259312 | Environment: | |
| Last Closed: | 2018-02-06 17:34:55 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 1259312 | ||
| Bug Blocks: | 1260923, 1268895 | ||
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Description
Nag Pavan Chilakam
2015-11-02 12:07:42 UTC
The doc text looks fine. We might also want to say that if it does hit 100% , the admin should copy a file off the mount to some safe place, then wait for files to get demoted before copying it back to the volume. Thanks Laura. This looks good. Here is a summary of discussions I had with Rafi related to this problem: 1. Creates falling on full hot tier. We need to have a min-free-disk check when we create files on hot tier. The reason min-free-disk might not be working as of now is that we create a linkto file on cold subvol and then create data file blindly on hot tier. Before trying to create a linkto file on cold subvol, we should check whether hot tier has enough space and only if that is true we should create a linkto file on cold tier and a data file on hot tier. 2. Writes to a full hot tier. We can add a min-free-disk check in writev_cbk. If the hot tier is getting full, client can instruct ctr (by lowering the heat) to consider the file for demotion. More details can be worked out (like constant migration of files b/w hot and cold tier when large number of files are being accessed etc). The advantage with tier when compared to dht is that we don't have to change layout to initiate migration. We can leverage ctr to migrate files to cold tier. The bug is reproduced on GlusterFS 3.12.3. Thank you for your bug report. This bug has documentation updated on the problem reported. Further we are no longer releasing any bug fixes or, other updates for Tier. This bug will be set to CLOSED WONTFIX to reflect this. Shyamsundar, What does it mean to "no longer releasing any bug fixes or, other updates for Tier"? Is the Tiering feature being deprecated or desupported? Thanks! Viktor Nosov. |