[LU-5931] Deactivated OST still contains data

• Type: Bug
• Resolution: Duplicate
• Priority: Major
• Affects Version/s: Lustre 2.4.1
• Labels: zfs
• Environment: ZFS on Linux 0.6.2, Scientific Linux 6.4

Epic/Theme

zfs

• Severity: 3

Epic

zfs

• Assignee: WC Triage
• Reporter: Eric Kolb

Description

Not sure this is the appropriate location for this issue but have little evidence elsewhere of a similar nature.

We have two ZFS backed OSTs (1 and 2) which we would like to remove from our Lustre environment for maintenance purposes. So we ran a 'lfs find /RSF1 --ost 1,2' to locate any stripes and subsequently copied the data to new files and removed the old. Running "lfs getstripe" confirms the new file resides and the remaining OSTs. The mystery is that the original OSTs still indicate that they house a significant amount of data.

UUID                   1K-blocks        Used   Available Use% Mounted on
RSF1-MDT0000_UUID       76477312     6747648    69727616   9% /RSF1[MDT:0]
RSF1-MDT0001_UUID       76416000     7168256    69245696   9% /RSF1[MDT:1]
* RSF1-OST0001_UUID     8053647744  3711864960  4341780736  46% /RSF1[OST:1]
* RSF1-OST0002_UUID     8053646848  3706844416  4346767616  46% /RSF1[OST:2]
RSF1-OST2776_UUID    12387717248  6162569728  6225144320  50% /RSF1[OST:10102]
RSF1-OST2840_UUID    12387719040  5993136000  6394579328  48% /RSF1[OST:10304]
RSF1-OST290a_UUID    12387720832  6174761856  6212955520  50% /RSF1[OST:10506]
RSF1-OST29d4_UUID    12387713408  6129103104  6258606848  49% /RSF1[OST:10708]
RSF1-OST2a9e_UUID    12387713536  5944379008  6443330944  48% /RSF1[OST:10910]
RSF1-OST2b68_UUID    12387710464  5959099904  6428606592  48% /RSF1[OST:11112]
RSF1-OST2c32_UUID    12387712384  6011423872  6376284800  49% /RSF1[OST:11314]

On the OSS nodes mounting those ZFS backed OSTs we run 'zdb -dd OST1 | grep "ZFS plain file"' for example and using the zfsobj2fid utility to map the resultant list of ZFS OID to FIDs. Then on a Lustre client we run:

lfs fid2path /RSF1 [0x280005221:0x11424:0x0]
fid2path error: No such file or directory

on all the FIDs but nothing is found.

This situation is concerning us as we will be permanently removing the two OSTs in question but is valid data still housed there?

Does the data still reside on the two OSTs in question because they are deactivated and thus read-only?

Sorry if this is a duplicate or an inappropriate location but have few avenues left to try and seems like a bug to us.

Issue Links

• is related to: LU-4825 lfs migrate not freeing space on OST