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path: root/include/linux/drbd_limits.h
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2017-08-29drbd: new disk-option disable-write-sameLars Ellenberg
Some backend devices claim to support write-same, but would fail actual write-same requests. Allow to set (or toggle) whether or not DRBD tries to support write-same. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2016-06-13drbd: allow larger max_discard_sectorsLars Ellenberg
Make sure we have at least 67 (> AL_UPDATES_PER_TRANSACTION) al-extents available, and allow up to half of that to be discarded in one bio. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-13drbd: when receiving P_TRIM, zero-out partial unaligned chunksLars Ellenberg
We can avoid spurious data divergence caused by partially-ignored discards on certain backends with discard_zeroes_data=0, if we translate partial unaligned discard requests into explicit zero-out. The relevant use case is LVM/DM thin. If on different nodes, DRBD is backed by devices with differing discard characteristics, discards may lead to data divergence (old data or garbage left over on one backend, zeroes due to unmapped areas on the other backend). Online verify would now potentially report tons of spurious differences. While probably harmless for most use cases (fstrim on a file system), DRBD cannot have that, it would violate our promise to upper layers that our data instances on the nodes are identical. To be correct and play safe (make sure data is identical on both copies), we would have to disable discard support, if our local backend (on a Primary) does not support "discard_zeroes_data=true". We'd also have to translate discards to explicit zero-out on the receiving (typically: Secondary) side, unless the receiving side supports "discard_zeroes_data=true". Which both would allocate those blocks, instead of unmapping them, in contrast with expectations. LVM/DM thin does set discard_zeroes_data=0, because it silently ignores discards to partial chunks. We can work around this by checking the alignment first. For unaligned (wrt. alignment and granularity) or too small discards, we zero-out the initial (and/or) trailing unaligned partial chunks, but discard all the aligned full chunks. At least for LVM/DM thin, the result is effectively "discard_zeroes_data=1". Arguably it should behave this way internally, by default, and we'll try to make that happen. But our workaround is still valid for already deployed setups, and for other devices that may behave this way. Setting discard-zeroes-if-aligned=yes will allow DRBD to use discards, and to announce discard_zeroes_data=true, even on backends that announce discard_zeroes_data=false. Setting discard-zeroes-if-aligned=no will cause DRBD to always fall-back to zero-out on the receiving side, and to not even announce discard capabilities on the Primary, if the respective backend announces discard_zeroes_data=false. We used to ignore the discard_zeroes_data setting completely. To not break established and expected behaviour, and suddenly cause fstrim on thin-provisioned LVs to run out-of-space, instead of freeing up space, the default value is "yes". Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-13drbd: Introduce new disk config option rs-discard-granularityPhilipp Reisner
As long as the value is 0 the feature is disabled. With setting it to a positive value, DRBD limits and aligns its resync requests to the rs-discard-granularity setting. If the sync source detects all zeros in such a block, the resync target discards the range on disk. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-07-10drbd: New net configuration option socket-check-timeoutPhilipp Reisner
In setups involving a DRBD-proxy and connections that experience a lot of buffer-bloat it might be necessary to set ping-timeout to an unusual high value. By default DRBD uses the same value to wait if a newly established TCP-connection is stable. Since the DRBD-proxy is usually located in the same data center such a long wait time may hinder DRBD's connect process. In such setups socket-check-timeout should be set to at least to the round trip time between DRBD and DRBD-proxy. I.e. in most cases to 1. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10drbd: implement csums-after-crash-onlyLars Ellenberg
Checksum based resync trades CPU cycles for network bandwidth, in situations where we expect much of the to-be-resynced blocks to be actually identical on both sides already. In a "network hickup" scenario, it won't help: all to-be-resynced blocks will typically be different. The use case is for the resync of *potentially* different blocks after crash recovery -- the crash recovery had marked larger areas (those covered by the activity log) as need-to-be-resynced, just in case. Most of those blocks will be identical. This option makes it possible to configure checksum based resync, but only actually use it for the first resync after primary crash. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2013-06-28drbd: Allow online change of al-stripes and al-stripe-sizePhilipp Reisner
Allow to change the AL layout with an resize operation. For that the reisze command gets two new fields: al_stripes and al_stripe_size. In order to make the operation crash save: 1) Lock out all IO and MD-IO 2) Write the super block with MDF_PRIMARY_IND clear 3) write the bitmap to the new location (all zeros, since we allow only while connected) 4) Initialize the new AL-area 5) Write the super block with the restored MDF_PRIMARY_IND. 6) Unfreeze all IO Since the AL-layout has no influence on the protocol, this operation needs to be beforemed on both sides of a resource (if intended). Signed-off-by: Andreas Gruenbacher <agruen@linbit.com> Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22drbd: adjust upper limit for activity log extentsLars Ellenberg
Now that the on-disk activity-log ring buffer size is adjustable, the maximum active set can become larger, and is now limited by the use of 16bit "labels". This increases the maximum working set from 6433 to 65534 extents, each of which covers an area of 4MiB. Which means that if you use the maximum, you'd have to resync more than 250 GiB after an unclean Primary shutdown. With capable backend storage and replication links, this is entirely feasible. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-11-08drbd: New disk option al-updatesPhilipp Reisner
By disabling al-updates one might increase performace. The price for that is that in case a crashed primary (that had al-updates disabled) is reintegraded, it will receive a full-resync instead of a bitmap based resync. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Load balancing of read requestsPhilipp Reisner
New config option for the disk secition "read-balancing", with the values: prefer-local, prefer-remote, round-robin, when-congested-remote. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: The minor_count module parameter is only a hint nowadaysPhilipp Reisner
* The max of minor_count is 255 * In drbdadm count the number of minors, instead of finding the highest minor number * No longer us the magic in the init script Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Fix the maximum accepted minor device numberAndreas Gruenbacher
The maximum minor device number allowed by the kernel is (1<<20 - 1). Reject device numbers higher than that to earlier catch possible errors. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Define scale factors in a single placeAndreas Gruenbacher
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Changed some defaultsPhilipp Reisner
* Enabled the resync controller, with a fill target of 50Kib. That gives reasonable resync speeds without tuning. A much better default than the 250KiB/s fixed. * Enable bitmap compression. It is save to use, and most people have more CPU power than network bandwidth. * ko-count of 7: Abort a connection if the peer fails to process a write request within 42 seconds. * al-extents of 1237: ~5 GiB seems to be a much more sane default these days. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: detach from frozen backing devicePhilipp Reisner
* drbd-8.3: documentation: Documented detach's --force and disk's --disk-timeout drbd: Implemented the disk-timeout option drbd: Force flag for the detach operation drbd: Allow new IOs while the local disk in in FAILED state drbd: Bitmap IO functions can not return prematurely if the disk breaks drbd: Added a kref to bm_aio_ctx drbd: Hold a reference to ldev while doing meta-data IO drbd: Keep a reference to the bio until the completion handler finished drbd: Implemented wait_until_done_or_disk_failure() drbd: Replaced md_io_mutex by an atomic: md_io_in_use drbd: moved md_io into mdev drbd: Immediately allow completion of IOs, that wait for IO completions on a failed disk drbd: Keep a reference to barrier acked requests Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Fixes from the 8.3 development branchPhilipp Reisner
* commit 'ae57a0a': drbd: Only print sanitize state's warnings, if the state change happens drbd: we should write meta data updates with FLUSH FUA drbd: fix limit define, we support 1 PiByte now drbd: fix log message argument order drbd: Typo in user-visible message. drbd: Make "(rcv|snd)buf-size" and "ping-timeout" available for the proxy, too. drbd: Allow keywords to be used in multiple config sections. drbd: fix typos in comments. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: allow ping-timeout of up to 30 secondsLars Ellenberg
Allow up to 300 centi-seconds to be configured for the "ping timeout". There may be setups where heavy congestion, huge buffers, and asymmetric bandwidth limitations may need a "huge" ping-timeout as work-around for "spurious connection loss" problems. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Use more generic constant namesAndreas Gruenbacher
These constants are useful for the same purpose in more than one place. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Rename DISK_SIZE_SECT -> DISK_SIZEAndreas Gruenbacher
We don't have the units in constant names in other places, either. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Fix the upper limit of resync-afterAndreas Gruenbacher
The 32-bit resync_after netlink field takes a device minor number as parameter, which is no longer limited to 255. We cannot statically verify which device numbers are valid, so set the ummer limit to the highest possible signed 32-bit integer. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Refer to resync-rate consistently throughout the codeAndreas Gruenbacher
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Also define the default values of boolean flags in a single placeAndreas Gruenbacher
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Remove left-over unused defineAndreas Gruenbacher
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: Introduce protocol version 100 headersAndreas Gruenbacher
The 8 byte header finally becomes too small. With the protocol 100 header we have 16 bit for the volume number, proper 32 bit for the data length, and 32 bit for further extensions in the future. Previous versions of drbd are using version 80 headers for all packets short enough for protocol 80. They support both header versions in worker context, but only version 80 headers in asynchronous context. For backwards compatibility, continue to use version 80 headers for short packets before protocol version 100. From protocol version 100 on, use the same header version for all packets. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08drbd: distribute former syncer_conf settings to disk, connection, and ↵Lars Ellenberg
resource level This commit breaks the API again. Move per-volume former syncer options into disk_conf. Move per-connection former syncer options into net_conf. Renamed the remainign sync_conf to res_opts Syncer settings have been changeable at runtime, so we need to prepare for these settings to be runtime-changeable in their new home as well. Introduce new configuration operations, and share the netlink attribute between "attach" (create new disk) and "disk-opts" (change options). Same for "connect" and "net-opts". Some fields cannot be changed at runtime, however. Introduce a new flag GENLA_F_INVARIANT to be able to trigger on that in the generated validation and assignment functions. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2011-10-14drbd: default to detach on-io-errorLars Ellenberg
Old default behaviour was "pass-on", which is not useful in production at all. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2011-10-14drbd: new on-disk activity log transaction formatLars Ellenberg
Use a new on-disk transaction format for the activity log, which allows for multiple changes to the active set per transaction. Using 4k transaction blocks, we can now get rid of the work-around code to deal with devices not supporting 512 byte logical block size. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2011-06-30drbd: fix limit define, we support 1 PiByte nowLars Ellenberg
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-10drbd: Corrected off-by-one error in DRBD_MINOR_COUNT_MAXPhilipp Reisner
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2011-03-10drbd: New configuration parameters for dealing with network congestionPhilipp Reisner
net { on_congestion {block|pull-ahead|disconnect}; congestion-fill {sectors}; congestion-extents {al-extents}; } Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2010-10-14drbd: Allow larger values for c-fill-target.Philipp Reisner
Connections through a compressing proxy might have more bits on the fly. 500MByte instead of 50MByte Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2010-10-14drbd: new configuration parameter c-min-rateLars Ellenberg
We now track the data rate of locally submitted resync related requests, and can thus detect non-resync activity on the lower level device. If the current sync rate is above c-min-rate, and the lower level device appears to be busy, we throttle the resyncer. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2010-10-14drbd: New sync parameters for the smart resync rate controllerPhilipp Reisner
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2010-10-14drbd: Finished the "on-no-data-accessible suspend-io;" functionalityPhilipp Reisner
When no data is accessible (no connection to the peer, nor a local disk) allow the user to select to freeze all IO operations instead of getting IO errors. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2010-05-18drbd: Four new configuration settings for resync speed controlPhilipp Reisner
To reasonably control resync speed over drbd-proxy connections, drbd has to measure the current delay of packets transmitted over the (possibly congested) data socket vs the meta-data socket. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2009-11-04change default: by default, use socket buffer auto tuningLars Ellenberg
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2009-10-01The DRBD driverPhilipp Reisner
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>